arduino lcd display serial monitor pricelist

Am pretty new to Arduino and could use some pointers. Am currently using an Arduino UNO to see a string of data and sending the data to the Serial Monitor in the ArduinoCC program for display.

Rather than needing a PC running a serial monitor connected to the Arduino, I would like the Arduino to send data to an LCD shield. I have just purchased a cheep one from ebay. Any ideas on where to start would be welcomb. Presumably I need to wire out of the USB connector and back into the LCD shield along with a code change to redirect the printed Ascii to shield or something ?

I am building a project that uses an HC-SR04 to detect distance and display it on an lcd screen. The distance is shown in the serial monitor. I hooked up the lcd screen and when i type in lcd.print("Justin") this will display. My question is how do I display serial data to the lcd screen. Here is my code.

If you do that, it will reboot the arduino but not reset the LCD (it still has power right?) -- the result will be bits sent to the LCD out of sequence to what the LCD controller chip is expecting. Who knows what the arduino could be telling the LCD to do! If this is the case, the LCD will never recover and will continue to display garbage.

I also have a Uno rev3 and with the same cable connection the LCD works fine as long as i dont open the serial monitor! So iam sure its not board problem and it looks farfetched to be coding problem. I guess if the cables are connected ok (as i wrote in first post) then it must be LCD problem.

The only way to temporally fix it is if i close the serial monitor, disconnect and reconnect the usb cable to arduino and then opening the serial monitor.. after 2 or 3 times doing that usually works with both open.

With this particular sketch i dont need to open the serial monitor but i have the same problem with all my sketches that include LCD. I just put this simple code (that also gives me the error i described) to see if we can pinpoint the problem.

Liquid crystal displays (LCDs) and LED displays offer a convenient and inexpensive way to provide a user interface for a project. This chapter explains how to connect and use common text and graphical LCD/LED panels with Arduino. By far the most popular LCD is the text panel based on the Hitachi HD44780 chip. This displays two or four lines of text, with 16 or 20 characters per line (32- and 40-character versions are available, but usually at higher prices). A library for driving text LCD displays is provided with Arduino, and you can print text on your LCD as easily as on the Serial Monitor (see Chapter 4), because LCD and serial share the same underlying print functions.

LCDs can do more than display simple text: words can be scrolled or highlighted and you can display a selection of special symbols and non-English characters.

You can create your own symbols and block graphics with a text LCD, but if you want fine graphical detail, you need a graphical display. Graphical LCD (GLCD) and graphical LED displays are available at a small price premium over text displays.

Graphical displays can have more wires connecting to Arduino than most other recipes in this book. Incorrect connections are the major cause of problems with graphical displays, so take your time wiring things up and triple-check that things are connected correctly. An inexpensive multimeter capable of measuring voltage and resistance is a big help for verifying that your wiring ...

Along 3 years I have been trying several leg mechanism, at first I decided to do a simple desing with tibial motor where placed on femur joint.This design had several problems, like it wasn"t very robust and the most importat is that having the motor (with big mass) that far from the rotating axis, caused that in some movements it generate unwanted dynamics to the robot body, making controlability worse.New version have both motors of femur/tibial limb at coxa frame, this ends with a very simple setup and at the same time, the heaviest masses of the mechanism are centered to the rotating axis of coxa limb, so even though the leg do fast movements, inertias won"t be strong enough to affect the hole robot mass, achieving more agility.Inverse Kinematics of the mechanismAfter building it I notice that this mechanism was very special for another reason, at the domain the leg normally moves, it acts as a diferential mecanism, this means that torque is almost all the time shared between both motor of the longer limbs. That was an improvent since with the old mechanism tibial motor had to hold most of the weight and it was more forced than the one for femur.To visualize this, for the same movement, we can see how tibial motor must travel more arc of angel that the one on the new version.In order to solve this mechanism, just some trigonometry is needed. Combining both cosine and sine laws, we can obtain desired angle (the one between femur and tibia) with respect to the angle the motor must achieve.Observing these equations, with can notice that this angle (the one between femur and tibia) depends on both servos angles, which means both motors are contributing to the movement of the tibia.Calibration of servosAnother useful thing to do if we want to control servo precisely is to print a calibration tool for our set up. As shown in the image below, in order to know where real angles are located, angle protactor is placer just in the origin of the rotating joint, and choosing 2 know angles we can match PWM signal to the real angles we want to manipulate simply doing a lineal relation between angles and PWM pulse length.Then a simple program in the serial console can be wrtten to let the user move the motor to the desired angle. This way the calibration process is only about placing motor at certain position and everything is done and we won"t need to manually introduce random values that can be a very tedious task.With this I have achieved very good calibrations on motors, which cause the robot to be very simetrial making the hole system more predictable. Also the calibration procedure now is very easy to do, as all calculations are done automatically. Check Section 1 for the example code for calibration.More about this can be seen in the video below, where all the building process is shown as well as the new leg in action.SECTION 1:In the example code below, you can see how calibration protocol works, it is just a function called calibrationSecuence() which do all the work until calibration is finished. So you only need to call it one time to enter calibration loop, for example by sending a "c" character thought the serial console.Also some useful function are used, like moving motor directly with analogWrite functions which all the calculations involved, this is a good point since no interrupts are used.This code also have the feature to calibrate the potentiometer coming from each motor.#define MAX_PULSE 2500 #define MIN_PULSE 560 /*---------------SERVO PIN DEFINITION------------------------*/ int m1 = 6;//FR int m2 = 5; int m3 = 4; int m4 = 28;//FL int m5 = 29; int m6 = 36; int m7 = 3;//BR int m8 = 2; int m9 = 1; int m10 = 7;//BL int m11 = 24; int m12 = 25; int m13 = 0;//BODY /*----------------- CALIBRATION PARAMETERS OF EACH SERVO -----------------*/ double lowLim[13] = {50, 30, 30, 50, 30, 30, 50, 30, 30, 50, 30, 30, 70}; double highLim[13] = {130, 150, 150, 130, 150, 150, 130, 150, 150, 130, 150, 150, 110}; double a[13] = { -1.08333, -1.06667, -1.07778, //FR -1.03333, 0.97778, 1.01111, //FL 1.03333, 1.05556, 1.07778, //BR 1.07500, -1.07778, -1.00000, //BL 1.06250 }; double b[13] = {179.0, 192.0, 194.5, //FR 193.0, 5.5, -7.5, //FL 7.0, -17.0, -16.0, //BR -13.5, 191.5, 157.0, //BL -0.875 }; double ae[13] = {0.20292, 0.20317, 0.19904 , 0.21256, -0.22492, -0.21321, -0.21047, -0.20355, -0.20095, -0.20265, 0.19904, 0.20337, -0.20226 }; double be[13] = { -18.59717, -5.70512, -2.51697, -5.75856, 197.29411, 202.72169, 185.96931, 204.11902, 199.38663, 197.89534, -5.33768, -32.23424, 187.48058 }; /*--------Corresponding angles you want to meassure at in your system-----------*/ double x1[13] = {120, 135, 90, 60, 135 , 90, 120, 135, 90, 60, 135, 90, 110}; //this will be the first angle you will meassure double x2[13] = {60, 90, 135, 120, 90, 135, 60, 90, 135, 120, 90, 135, 70};//this will be the second angle you will meassure for calibration /*--------You can define a motor tag for each servo--------*/ String motorTag[13] = {"FR coxa", "FR femur", "FR tibia", "FL coxa", "FL femur", "FL tibia", "BR coxa", "BR femur", "BR tibia", "BL coxa", "BL femur", "BL tibia", "Body angle" }; double ang1[13] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; double ang2[13] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; float xi[500]; float yi[500]; float fineAngle; float fineL; float fineH; int motorPin; int motor = 0; float calibrationAngle; float res = 1.0; float ares = 0.5; float bres = 1.0; float cres = 4.0; float rawAngle; float orawAngle; char cm; char answer; bool interp = false; bool question = true; bool swing = false; int i; double eang; int freq = 100; // PWM frecuency can be choosen here. void connectServos() { analogWriteFrequency(m1, freq); //FR coxa digitalWrite(m1, LOW); pinMode(m1, OUTPUT); analogWriteFrequency(m2, freq); //femur digitalWrite(m2, LOW); pinMode(m2, OUTPUT); analogWriteFrequency(m3, freq); //tibia digitalWrite(m3, LOW); pinMode(m3, OUTPUT); analogWriteFrequency(m4, freq); //FL coxa digitalWrite(m4, LOW); pinMode(m4, OUTPUT); analogWriteFrequency(m5, freq); //femur digitalWrite(m5, LOW); pinMode(m5, OUTPUT); analogWriteFrequency(m6, freq); //tibia digitalWrite(m6, LOW); pinMode(m6, OUTPUT); analogWriteFrequency(m7, freq); //FR coxa digitalWrite(m7, LOW); pinMode(m7, OUTPUT); analogWriteFrequency(m8, freq); //femur digitalWrite(m8, LOW); pinMode(m8, OUTPUT); analogWriteFrequency(m9, freq); //tibia digitalWrite(m9, LOW); pinMode(m9, OUTPUT); analogWriteFrequency(m10, freq); //FR coxa digitalWrite(m10, LOW); pinMode(m10, OUTPUT); analogWriteFrequency(m11, freq); //femur digitalWrite(m11, LOW); pinMode(m11, OUTPUT); analogWriteFrequency(m12, freq); //tibia digitalWrite(m12, LOW); pinMode(m12, OUTPUT); analogWriteFrequency(m13, freq); //body digitalWrite(m13, LOW); pinMode(m13, OUTPUT); } void servoWrite(int pin , double angle) { float T = 1000000.0f / freq; float usec = float(MAX_PULSE - MIN_PULSE) * (angle / 180.0) + (float)MIN_PULSE; uint32_t duty = int(usec / T * 4096.0f); analogWrite(pin , duty); } double checkLimits(double angle , double lowLim , double highLim) { if ( angle >= highLim ) { angle = highLim; } if ( angle <= lowLim ) { angle = lowLim; } return angle; } int motorInfo(int i) { enc1 , enc2 , enc3 , enc4 , enc5 , enc6 , enc7 , enc8 , enc9 , enc10 , enc11 , enc12 , enc13 = readEncoders(); if (i == 0) { rawAngle = enc1; motorPin = m1; } else if (i == 1) { rawAngle = enc2; motorPin = m2; } else if (i == 2) { rawAngle = enc3; motorPin = m3; } else if (i == 3) { rawAngle = enc4; motorPin = m4; } else if (i == 4) { rawAngle = enc5; motorPin = m5; } else if (i == 5) { rawAngle = enc6; motorPin = m6; } else if (i == 6) { rawAngle = enc7; motorPin = m7; } else if (i == 7) { rawAngle = enc8; motorPin = m8; } else if (i == 8) { rawAngle = enc9; motorPin = m9; } else if (i == 9) { rawAngle = enc10; motorPin = m10; } else if (i == 10) { rawAngle = enc11; motorPin = m11; } else if (i == 11) { rawAngle = enc12; motorPin = m12; } else if (i == 12) { rawAngle = enc13; motorPin = m13; } return rawAngle , motorPin; } void moveServos(double angleBody , struct vector anglesServoFR , struct vector anglesServoFL , struct vector anglesServoBR , struct vector anglesServoBL) { //FR anglesServoFR.tetta = checkLimits(anglesServoFR.tetta , lowLim[0] , highLim[0]); fineAngle = a[0] * anglesServoFR.tetta + b[0]; servoWrite(m1 , fineAngle); anglesServoFR.alpha = checkLimits(anglesServoFR.alpha , lowLim[1] , highLim[1]); fineAngle = a[1] * anglesServoFR.alpha + b[1]; servoWrite(m2 , fineAngle); anglesServoFR.gamma = checkLimits(anglesServoFR.gamma , lowLim[2] , highLim[2]); fineAngle = a[2] * anglesServoFR.gamma + b[2]; servoWrite(m3 , fineAngle); //FL anglesServoFL.tetta = checkLimits(anglesServoFL.tetta , lowLim[3] , highLim[3]); fineAngle = a[3] * anglesServoFL.tetta + b[3]; servoWrite(m4 , fineAngle); anglesServoFL.alpha = checkLimits(anglesServoFL.alpha , lowLim[4] , highLim[4]); fineAngle = a[4] * anglesServoFL.alpha + b[4]; servoWrite(m5 , fineAngle); anglesServoFL.gamma = checkLimits(anglesServoFL.gamma , lowLim[5] , highLim[5]); fineAngle = a[5] * anglesServoFL.gamma + b[5]; servoWrite(m6 , fineAngle); //BR anglesServoBR.tetta = checkLimits(anglesServoBR.tetta , lowLim[6] , highLim[6]); fineAngle = a[6] * anglesServoBR.tetta + b[6]; servoWrite(m7 , fineAngle); anglesServoBR.alpha = checkLimits(anglesServoBR.alpha , lowLim[7] , highLim[7]); fineAngle = a[7] * anglesServoBR.alpha + b[7]; servoWrite(m8 , fineAngle); anglesServoBR.gamma = checkLimits(anglesServoBR.gamma , lowLim[8] , highLim[8]); fineAngle = a[8] * anglesServoBR.gamma + b[8]; servoWrite(m9 , fineAngle); //BL anglesServoBL.tetta = checkLimits(anglesServoBL.tetta , lowLim[9] , highLim[9]); fineAngle = a[9] * anglesServoBL.tetta + b[9]; servoWrite(m10 , fineAngle); anglesServoBL.alpha = checkLimits(anglesServoBL.alpha , lowLim[10] , highLim[10]); fineAngle = a[10] * anglesServoBL.alpha + b[10]; servoWrite(m11 , fineAngle); anglesServoBL.gamma = checkLimits(anglesServoBL.gamma , lowLim[11] , highLim[11]); fineAngle = a[11] * anglesServoBL.gamma + b[11]; servoWrite(m12 , fineAngle); //BODY angleBody = checkLimits(angleBody , lowLim[12] , highLim[12]); fineAngle = a[12] * angleBody + b[12]; servoWrite(m13 , fineAngle); } double readEncoderAngles() { enc1 , enc2 , enc3 , enc4 , enc5 , enc6 , enc7 , enc8 , enc9 , enc10 , enc11 , enc12 , enc13 = readEncoders(); eang1 = ae[0] * enc1 + be[0]; eang2 = ae[1] * enc2 + be[1]; eang3 = ae[2] * enc3 + be[2]; eang4 = ae[3] * enc4 + be[3]; eang5 = ae[4] * enc5 + be[4]; eang6 = ae[5] * enc6 + be[5]; eang7 = ae[6] * enc7 + be[6]; eang8 = ae[7] * enc8 + be[7]; eang9 = ae[8] * enc9 + be[8]; eang10 = ae[9] * enc10 + be[9]; eang11 = ae[10] * enc11 + be[10]; eang12 = ae[11] * enc12 + be[11]; eang13 = ae[12] * enc13 + be[12]; return eang1 , eang2 , eang3 , eang4 , eang5 , eang6 , eang7 , eang8 , eang9 , eang10 , eang11 , eang12 , eang13; } void calibrationSecuence( ) { //set servos at their middle position at firstt for (int i = 0; i <= 12; i++) { rawAngle , motorPin = motorInfo(i); servoWrite(motorPin , 90); } // sensorOffset0 = calibrateContacts(); Serial.println(" "); Serial.println("_________________________________SERVO CALIBRATION ROUTINE_________________________________"); Serial.println("___________________________________________________________________________________________"); Serial.println("(*) Don"t send several caracter at the same time."); delay(500); Serial.println(" "); Serial.println("Keyboard: "x"-> EXIT CALIBRATION. "c"-> ENTER CALIBRATION."); Serial.println(" "i"-> PRINT INFORMATION. "); Serial.println(" "); Serial.println(" "n"-> CHANGE MOTOR (+). "b" -> CHANGE MOTOR (-)."); Serial.println(" "m"-> START CALIBRATION."); Serial.println(" "q"-> STOP CALIBRATION."); Serial.println(" "); Serial.println(" "r"-> CHANGE RESOLUTION."); Serial.println(" "p"-> ADD ANGLE. "o"-> SUBTRACT ANGLE. "); Serial.println(" "s"-> SAVE ANGLE."); delay(500); Serial.println(" "); Serial.println("---------------------------------------------------------------------------------------------------"); Serial.print("SELECTED MOTOR: "); Serial.print(motorTag[motor]); Serial.print(". SELECTED RESOLUTION: "); Serial.println(res); while (CAL == true) { if (Serial.available() > 0) { cm = Serial.read(); if (cm == "x") { Serial.println("Closing CALIBRATION program..."); CAL = false; secuence = false; startDisplay(PAGE); angleBody = 90; anglesIKFR.tetta = 0.0; anglesIKFR.alpha = -45.0; anglesIKFR.gamma = 90.0; anglesIKFL.tetta = 0.0; anglesIKFL.alpha = -45.0; anglesIKFL.gamma = 90.0; anglesIKBR.tetta = 0.0; anglesIKBR.alpha = 45.0; anglesIKBR.gamma = -90.0; anglesIKBL.tetta = 0.0; anglesIKBL.alpha = 45.0; anglesIKBL.gamma = -90.0; } else if (cm == "i") { // + Serial.println(" "); Serial.println("---------------------------------------------------------------------------------------------------"); Serial.println("---------------------------------------------------------------------------------------------------"); Serial.println("(*) Don"t send several caracter at the same time."); delay(500); Serial.println(" "); Serial.println("Keyboard: "x"-> EXIT CALIBRATION. "c"-> ENTER CALIBRATION."); Serial.println(" "i"-> PRINT INFORMATION. "); Serial.println(" "); Serial.println(" "n"-> CHANGE MOTOR (+). "b" -> CHANGE MOTOR (-)."); Serial.println(" "m"-> START CALIBRATION."); Serial.println(" "q"-> STOP CALIBRATION."); Serial.println(" "); Serial.println(" "r"-> CHANGE RESOLUTION."); Serial.println(" "p"-> ADD ANGLE. "o"-> SUBTRACT ANGLE. "s"-> SAVE ANGLE."); Serial.println(" "); delay(500); Serial.println(" "); Serial.println("---------------------------------------------------------------------------------------------------"); Serial.println(" "); Serial.print("SELECTED MOTOR: "); Serial.print(motorTag[motor]); Serial.print(". SELECTED RESOLUTION: "); Serial.println(res); Serial.println("Actual parameters of the motor: "); Serial.print("High limit: "); Serial.print(highLim[motor]); Serial.print(" Low limit: "); Serial.print(lowLim[motor]); Serial.print(" Angle 1: "); Serial.print(ang1[motor]); Serial.print(" Angle 2: "); Serial.println(ang2[motor]); Serial.println("---------------------------------------------------------------------------------------------------"); } else if (cm == "m") { // + secuence = true; } else if (cm == "s") { // + } else if (cm == "n") { // + motor++; if (motor >= 13) { motor = 0; } Serial.print("SELECTED MOTOR: "); Serial.println(motorTag[motor]); } else if (cm == "b") { // + motor--; if (motor < 0) { motor = 13 - 1; } Serial.print("SELECTED MOTOR: "); Serial.println(motorTag[motor]); } else if (cm == "r") { // + if (res == ares) { res = bres; } else if (res == bres) { res = cres; } else if (res == cres) { res = ares; } Serial.print("SELECTED RESOLUTION: "); Serial.println(res); } } if (secuence == true) { Serial.print("Starting secuence for motor: "); Serial.println(motorTag[motor]); for (int i = 0; i <= 30; i++) { delay(20); Serial.print("."); } Serial.println("."); while (question == true) { unsigned long currentMicros = micros(); if (currentMicros - previousMicros >= 100000) { previousMicros = currentMicros; if (Serial.available() > 0) { answer = Serial.read(); if (answer == "y") { question = false; interp = true; secuence = true; } else if (answer == "n") { question = false; interp = false; secuence = true; } else { Serial.println("Please, select Yes(y) or No(n)."); } } } } answer = "t"; question = true; if (interp == false) { Serial.println("___"); Serial.println(" | Place motor at 1ts position and save angle"); Serial.println(" | This position can be the higher one"); rawAngle , motorPin = motorInfo(motor); calibrationAngle = 90; //start calibration at aproximate middle position of the servo. while (secuence == true) { /* find first calibration angle */ if (Serial.available() > 0) { cm = Serial.read(); if (cm == "p") { // + Serial.print(" | +"); Serial.print(res); Serial.print(" : "); calibrationAngle = calibrationAngle + res; servoWrite(motorPin , calibrationAngle); Serial.println(calibrationAngle); } else if (cm == "o") { // - Serial.print(" | -"); Serial.print(res); Serial.print(" : "); calibrationAngle = calibrationAngle - res; servoWrite(motorPin , calibrationAngle); Serial.println(calibrationAngle); } else if (cm == "r") { // + if (res == ares) { res = bres; } else if (res == bres) { res = cres; } else if (res == cres) { res = ares; } Serial.print("SELECTED RESOLUTION: "); Serial.println(res); } else if (cm == "q") { // quit secuence secuence = false; Serial.println(" | Calibration interrupted!!"); } else if (cm == "s") { // save angle ang1[motor] = calibrationAngle; secuence = false; Serial.print(" | Angle saved at "); Serial.println(calibrationAngle); } } } if (cm == "q") { Serial.println(" |"); } else { secuence = true; Serial.println("___"); Serial.println(" | Place motor at 2nd position and save angle"); Serial.println(" | This position can be the lower one"); } while (secuence == true) { /* find second calibration angle */ if (Serial.available() > 0) { cm = Serial.read(); if (cm == "p") { // + Serial.print(" | +"); Serial.print(res); Serial.print(" : "); calibrationAngle = calibrationAngle + res; servoWrite(motorPin , calibrationAngle); Serial.println(calibrationAngle); } else if (cm == "o") { // - Serial.print(" | -"); Serial.print(res); Serial.print(" : "); calibrationAngle = calibrationAngle - res; servoWrite(motorPin , calibrationAngle); Serial.println(calibrationAngle); } else if (cm == "r") { // + if (res == ares) { res = bres; } else if (res == bres) { res = cres; } else if (res == cres) { res = ares; } Serial.print("SELECTED RESOLUTION: "); Serial.println(res); } else if (cm == "q") { // quit secuence secuence = false; Serial.println(" | Calibration interrupted!!"); } else if (cm == "s") { // save angle ang2[motor] = calibrationAngle; secuence = false; Serial.print(" | Angle saved at "); Serial.println(calibrationAngle); } } } /*--------------------start calibration calculations------------------*/ if (cm == "q") { Serial.println("___|"); Serial.println("Calibration finished unespected."); Serial.println(" Select another motor."); Serial.print("SELECTED MOTOR: "); Serial.print(motorTag[motor]); Serial.print(". SELECTED RESOLUTION: "); Serial.println(res); } else { Serial.println("___"); Serial.println(" |___"); Serial.print( " | | Interpolating for motor: "); Serial.println(motorTag[motor]); secuence = true; //real angle is calculated interpolating both angles to a linear relation. a[motor] = (ang2[motor] - ang1[motor]) / (x2[motor] - x1[motor]); b[motor] = ang1[motor] - x1[motor] * (ang2[motor] - ang1[motor]) / (x2[motor] - x1[motor]); Serial.println(" | |"); } interp = true; } /*---------------------------make swing movement to interpolate motor encoder-----*/ if (interp == true and secuence == true) { delay(200); double x; int k = 0; int stp = 180; swing = true; i = 0; orawAngle , motorPin = motorInfo(motor); previousMicros = 0; while (swing == true) { // FIRST unsigned long currentMicros = micros(); if (currentMicros - previousMicros >= 10000) { // save the last time you blinked the LED previousMicros = currentMicros; x = x2[motor]; calibrationAngle = a[motor] * x + b[motor]; servoWrite(motorPin , calibrationAngle); rawAngle , motorPin = motorInfo(motor); if ((i % 3) == 0) { yi[k+1] = x; xi[k] = rawAngle; Serial.print(" | | Real ang: "); Serial.print(x); Serial.print(" -> Servo ang: "); Serial.print(calibrationAngle); Serial.print(" Enc: "); Serial.println(rawAngle); k++; } if (i >= stp) { swing = false; } i++; } } swing = true; i = 0; while (swing == true) { // moving unsigned long currentMicros = micros(); if (currentMicros - previousMicros >= 10000) { // save the last time you blinked the LED previousMicros = currentMicros; x = x2[motor] + float(i) * (x1[motor] - x2[motor]) / stp; calibrationAngle = a[motor] * x + b[motor]; servoWrite(motorPin , calibrationAngle); rawAngle , motorPin = motorInfo(motor); if ((i % 6) == 0) { yi[k+1] = x; xi[k] = rawAngle; Serial.print(" | | Real ang: "); Serial.print(x); Serial.print(" -> Servo ang: "); Serial.print(calibrationAngle); Serial.print(" Enc: "); Serial.println(rawAngle); k++; } if (i >= stp) { swing = false; } i++; } } swing = true; i = 0; while (swing == true) { // SECOND unsigned long currentMicros = micros(); if (currentMicros - previousMicros >= 10000) { // save the last time you blinked the LED previousMicros = currentMicros; x = x1[motor]; calibrationAngle = a[motor] * x + b[motor]; servoWrite(motorPin , calibrationAngle); rawAngle , motorPin = motorInfo(motor); if ((i % 3) == 0) { yi[k+1] = x; xi[k] = rawAngle; Serial.print(" | | Real ang: "); Serial.print(x); Serial.print(" -> Servo ang: "); Serial.print(calibrationAngle); Serial.print(" Enc: "); Serial.println(rawAngle); k++; } if (i >= stp) { swing = false; } i++; } } swing = true; i = 0; while (swing == true) { // moving unsigned long currentMicros = micros(); if (currentMicros - previousMicros >= 10000) { // save the last time you blinked the LED previousMicros = currentMicros; x = x1[motor] + float(i) * (x2[motor] - x1[motor]) / stp; calibrationAngle = a[motor] * x + b[motor]; servoWrite(motorPin , calibrationAngle); rawAngle , motorPin = motorInfo(motor); if ((i % 6) == 0) { yi[k+1] = x; xi[k] = rawAngle; Serial.print(" | | Real ang: "); Serial.print(x); Serial.print(" -> Servo ang: "); Serial.print(calibrationAngle); Serial.print(" Enc: "); Serial.println(rawAngle); k++; } if (i >= stp) { swing = false; } i++; } } swing = true; i = 0; while (swing == true) { // FIRST unsigned long currentMicros = micros(); if (currentMicros - previousMicros >= 10000) { // save the last time you blinked the LED previousMicros = currentMicros; x = x2[motor]; calibrationAngle = a[motor] * x + b[motor]; servoWrite(motorPin , calibrationAngle); rawAngle , motorPin = motorInfo(motor); if ((i % 3) == 0) { yi[k+1] = x; xi[k] = rawAngle; Serial.print(" | | Real ang: "); Serial.print(x); Serial.print(" -> Servo ang: "); Serial.print(calibrationAngle); Serial.print(" Enc: "); Serial.println(rawAngle); k++; } if (i >= stp) { swing = false; } i++; } } swing = true; i = 0; while (swing == true) { // moving unsigned long currentMicros = micros(); if (currentMicros - previousMicros >= 10000) { // save the last time you blinked the LED previousMicros = currentMicros; x = x2[motor] + float(i) * (x1[motor] - x2[motor]) / stp; calibrationAngle = a[motor] * x + b[motor]; servoWrite(motorPin , calibrationAngle); rawAngle , motorPin = motorInfo(motor); if ((i % 6) == 0) { yi[k+1] = x; xi[k] = rawAngle; Serial.print(" | | Real ang: "); Serial.print(x); Serial.print(" -> Servo ang: "); Serial.print(calibrationAngle); Serial.print(" Enc: "); Serial.println(rawAngle); k++; } if (i >= stp) { swing = false; } i++; } } swing = true; i = 0; while (swing == true) { // SECOND unsigned long currentMicros = micros(); if (currentMicros - previousMicros >= 10000) { // save the last time you blinked the LED previousMicros = currentMicros; x = x1[motor]; calibrationAngle = a[motor] * x + b[motor]; servoWrite(motorPin , calibrationAngle); rawAngle , motorPin = motorInfo(motor); if ((i % 3) == 0) { yi[k+1] = x; xi[k] = rawAngle; Serial.print(" | | Real ang: "); Serial.print(x); Serial.print(" -> Servo ang: "); Serial.print(calibrationAngle); Serial.print(" Enc: "); Serial.println(rawAngle); k++; } if (i >= stp) { swing = false; } i++; } } Serial.println(" | | Interpolation finished!"); /*-------Calculate linear interpolation of the encoder from 60 meassures done in swing------*/ double sx = 0; double sy = 0; double sx2 = 0; double sy2 = 0; double sxy = 0; double xmean = 0; double ymean = 0; int n = 300; for (int i = 0 ; i < n ; i++) { sx += xi[i+10]; sy += yi[i+10]; sx2 += xi[i+10] * xi[i+10]; sy2 += yi[i+10] * yi[i+10]; sxy += xi[i+10] * yi[i+10]; } ae[motor] = (n * sxy - sx * sy) / (n * sx2 - sx * sx); //sxy / sx2; // be[motor] = (sy - ae[motor] * sx) / n; //ymean - ae[motor] * xmean; Serial.println(" | | Moving back to ZERO position."); // turn the motor back to middle position swing = true; i = 0; while (swing == true) { unsigned long currentMicros = micros(); if (currentMicros - previousMicros >= 10000) { // save the last time you blinked the LED previousMicros = currentMicros; x = x1[motor] + float(i) * (90 - x1[motor]) / 60; calibrationAngle = a[motor] * x + b[motor]; servoWrite(motorPin , calibrationAngle); rawAngle , motorPin = motorInfo(motor); eang = ae[motor] * rawAngle + be[motor]; if ((i % 4) == 0) { Serial.print(" | | Servo ang: "); Serial.print(calibrationAngle); Serial.print(" -> Real ang: "); Serial.print(x); Serial.print(" -> Encoder ang: "); Serial.println(eang); } if (i >= 60) { swing = false; } i++; } } Serial.println("___|___|"); Serial.println(" | "); Serial.println("___"); Serial.println(" | Calibration finished satisfactory. Results data:"); Serial.print(" | HIGH lim: "); Serial.print(highLim[motor]); Serial.print(" LOW lim: "); Serial.println(lowLim[motor]); Serial.print(" | angle 1: "); Serial.print(ang1[motor]); Serial.print(" angle 2 "); Serial.println(ang2[motor]); Serial.print(" | Regression Motor a: "); Serial.print(a[motor], 5); Serial.print(" b: "); Serial.println(b[motor], 5); Serial.print(" | Regression Encoder a: "); Serial.print(ae[motor], 5); Serial.print(" b: "); Serial.println(be[motor], 5); Serial.println(" |"); Serial.println(" | ______________________________________________________________"); Serial.println(" | | |"); Serial.println(" | | This code won"t be able to save the updated parameters |"); Serial.println(" | | once the robot is shutted down. |"); Serial.println(" | | |"); Serial.println(" | | Please, write down the results |"); Serial.println(" | | and save them in the definition of each variable. |"); Serial.println(" | |_____________________________________________________________|"); Serial.println(" |"); Serial.println("___|"); Serial.println(" Select another motor."); Serial.print("SELECTED MOTOR: "); Serial.print(motorTag[motor]); Serial.print(". SELECTED RESOLUTION: "); Serial.println(res); } interp = false; secuence = false; } } SAFE = false; Serial.println("Calibration killed"); } // END OF CALIBRATION

In this tutorial, I’ll show how to perform I2C communication with two Arduino boards. The potentiometer and LCD are used to display the data sharing from a master Arduino to the slave one. The tutorial shows the simulation results for the potentiometer values read from the master and applied to the slave and vice versa, performed controlling the related LCD attached.

Inter-Integrated Circuit (I2C), also spelt IIC, is a synchronous, master/slave, packet-switched, single-ended serial communication bus that supports multiple controllers and targets. In order to transmit and receive data using the I2C protocol, it uses two lines: a serial clock pin (SCL), which pulses periodically by the Uno Controller (master) board, and a serial data pin (SDA), through which data pass between the transmitter and receiver.

Each Arduino will read the value from its nearest potentiometer and send it to the other Arduino. The 2 potentiometers on the LCDs are just to control the contrast and don’t affect the read value variable.

LCD wires are VCC=5V, GND= GND, rs=2, enable = 7, D4=8, D5=9, D6=10, D7=11 for both master and slave Contrast = Connected with a potentiometer to change the value for a contrast setting

Connect your PC to Arduino and open Arduino IDE. For the very first steps, you can refer to Connecting Windows PC with Arduino tutorial. You can get the .ino code and libraries from my download area with the following link:

You also need to install the LiquidCrystal library, according to my Install Arduino Libraries: methods to add libraries with Arduino IDE tutorial, available from the Library Manager in Arduino IDE:

In the setup, we open a the serial monitor at a baud rate of 9600 to visualize the data coming after receiving. The wire.begin() command enables an 8-bit data communication.

We also initialize our LCD with a welcome message that will last 5 seconds (5.000 milliseconds). Then, we’ll clear the LDC display in order to get it for receiving data:

In the loop section, the master requires to the I2C device with address “8” (our Arduino slave) 1 byte of data. We also start listening to the communication to get it stored in our MasterReceive variable. This will be the value that we’ll show in our Master LCD, received from the Slave:

All the data have been now shared between Master and Slave. The loop ends by managing their presentation on LCD (and in our serial monitor), finally adding a 500 milliseconds delay before running a new loop:

We also need a variable to store what values have been transmitted by Master, in order to get them from the receiveEvent() function and display them in our main loop:

When the potentiometer data from the master changes by rotating it, the changed data are sent to the slave to display on the slave LCD. Similarly, when the potentiometer at the slave rotates, values will show on the master LCD. The communication means between both boards I2C is set by pins A4 and A5.

Either for benchmarking purposes or as external telemetry to help you stay within the acceptable range for your computer power, super users usually have the desire to have a way of knowing what the performance numbers of your PC are. For today’s tutorial, we will build a PC Hardware monitor which is capable of obtaining several performance-related parameters from your computer and displaying them on a Nokia 5110 LCD display.

Our PC Hardware monitor tutorial is based on the Arduino Nano microcontroller and aNokia 5110 LCD Display. We have extensively used both of the components in past tutorials, especially the Nokia 5110 LCD Display for which we have done tutorials on displaying custom graphics, and several more tutorials on creating acustom menu on the display etc.

The principle of operation of today’s project is based on the “Grant Snatts” Hardware Serial Monitor project, which in turn, is based on the SerialSender utility which uses the open-source OpenHardwareMonitorLib.dll to sniff the sensors of the dedicated GPUs, graphic Cards, CPU and motherboards of most modern personal computers whilst, also pooling windows hardware stats. This stats and data are then obtained by the Arduino over the serial port and displayed on the Nokia 5110 LCD display.  To do a better than other versions of the project out there, rather than just displaying the data, we will plot performance graphs to show information the CPU Load and the CPU Clock.

At the end of today’s tutorial, you would know things like graph plotting etc on the Nokia 5110 as well as interacting with the PC directly using the Arduino.

The schematics for this project is simple and should be familiar if you have been following several of our tutorials. Since the project is made up of just two main components, all we need to do is connect the Nokia 5110 LCD Display to the Arduino as shown in the schematics below;

The code for this project is quite straight forward. We obtain PC performance information via serial communication from the hardware monitor utility and display on the LCD as a graph and in raw data form.

To achieve this, we use N5110_SPI.h minimalistic Arduino library by cbm80amiga. The library uses a very small amount of MCU resources and contains methods that reduce the amount of code you need to write to display data on the Nokia 5110 LCD.

Next, We write the void setup function. We start the function by initializing the serial monitor which we will use for debug purposes. Next, we initialize the LCD, set the font and display the string “Connecting” at the center of the screen.

With that done, we create the function readSerial. This function does 80% of the work involved in this project. The function picks up the data sent by the utility over serial and extracts the CPU Clock, the RAM usage, CPU temperature and CPU load information from the serial data stream.

Next, is the void loop() function. The void loop function checks to see if the serial data is available by calling the readserial function. If data is available from the PC, it then displays the extracted data from the readserial() function on the LCD Display, while also using the LCD.fillWin() and drawGraphBar() function to plot the graph.

With the code complete and the hardware connected as described under the schematics, connect the Arduino board to the computer and upload the code. Launch the hardware monitor software (attached under the download section) as an administrator and select the right com port to match the port on which your Arduino board is connected.

In a previous paper I described wiring up three MAX7219 8×8 dot led matrix devices with an Arduino microboard to create a news ticker running the latest headlines. Although being successful from the point of creating a news ticker device, that ticker is a static device, that is that the ticker headlines are embedded as a text string in the Arduino sketch. To change the ticker headlines one needs to edit the sketch.

I envisage that in the real world a news ticker operator sits behind a desk with a keyboard and a display in front of him. From this comfortable position the operator launches to the crowds sensational headlines displayed on the big news ticker mounted on the outside of the newspaper building.

In other words: is it possible to construct an interactive news ticker. It should run a fixed introductory text followed by a few dots and next by the big news headlines that do matter. For this purpose we need a computer running the Arduino Serial Monitor, a news ticker based on MAX7219 dot led matrix devices, and a display that shows the current headline being run on the big news ticker.

An Arduino Uno or Nano microcontroller board and three (or more, up to eight) MAX7219 controller 8×8 dot led matrix displays (shorthand: ‘8×8 dot matrix device’), and a lcd display. Prices in various internet shops of these devices are in the range of US$ 2-10 a piece. Further needed are jumper wires and three breadboards, a 220Ω resistor and a 10 kΩ potentiometer.

I made my news ticker by daisy-chaining three 8×8 dot matrix devices (Figure 1), and connecting this chain to an Arduino Nano. Each 8×8 dot matrix device operates under a SPI controller protocol. The entire chain is powered and controlled via five wires: 5V, GND, DIN, CS and CLK. 5V and GND are connected with the 5CV and GND pins of the Arduino; the pins DIN, CS and CLK are connected with digital pins 10, 8 and 9 of the Arduino, respectively. Note that the connectivity presented here of DIN, CS and CLK is different from the usual connectivity (12-10-11) because pins 11 and 12 are necessary to wire the lcd display.

The lcd display is connected to the Arduino in the standard way: pin 1 is connected to GND, pin 2 to 5V. Pin 3 is connected to the wiper of a 10 kΩ potentiometer (other pins of the potmeter connected to 5V and GND). Pins 4, 5 and 6 are connected to the Arduino pins 12, GND and 11, respectively. Data runs to the lcd via the lcd’s pins 11 through 14 which are connected to, respectively, pins 5, 4, 3 and 2 of the Arduino. Background light in the lcd is powered via pin 15 (either connected to 3,3V or via a 220Ω resistor to 5V. Don’t forget to connect pin 16 of the lcd display with GND.

I applied a 20×4 lcd display simply because it was available. A 16×2 lcd display can do the job as well. The display shows two lines: a fixed line “News ticker text:” and a line in the lower portion of the lcd display showing the actually running headline news. The characters for this headline need to be typed into the Serial Monitor  interface on the computer after starting the sketch. The lcd thus acts as a simple monitor.

4.    Compile the sketch to the microcontroller board. After successful compilation the lcd will display on row 1, “News ticker text:” and on row two a continuous line,

The lcd will display on lines 3 and 4 the ticker headline text, cut off at 35 characters in order to keep the display tidy. This action does not affect the headline running on the news ticker.

In the present sketch the news ticker is instructed to display a text string  “News Ticker . . .” followed by the news headline. To introduce a new running headline on the news ticker the sketch needs to be recompiled. It is possible to write a sketch for interactive, continuously running ticker where the running news headline can be replaced by a fresh headline while the ticker keeps running all the time. The challenge here is that the Arduino is a system that does not support multiple processes running simultaneously. It either runs the news ticker while Serial Monitor is silent, or it runs the Serial Monitor while the news ticker is silent. While text is being typed into the Serial Monitor window the news ticker runs slower or its running  ‘hiccups’. One solution is to ‘feed’ the Arduino’s working memory slowly by adding one character of a string at a time while the news ticker keeps running, at the cost of ticker running speed. The microprocessor in the Arduino platform is powerful enough to support this solution, although the response times between hitting the Enter key to send the typed-in text to the Arduino and the actual start of the headline being displayed in the running news ticker will be disappointingly long. I am inclined to research a solution that involves running each separate process on a separate, dedicated Arduino. Both Arduino’s are then connected via a serial or master-slave protocol: the master listens for headline text, the slave runs the news ticker.

Newbie here, working on a simple thermostat kinda project. A DHT22 and a 20 x 4 LCD display. Most of the code is copied from a tutorial and I have started modifying it.

The project would turn on a motor when the humidity reached a certain point. I have an LED on a breadboard (motor I"d like to turn on). And it works! At 70%, from me breathing heavily on the sensor, the LED turns on. But as you can see in the code below, the display shows the temp and humidity on the 2nd and 3rd lines. An "if" statement is supposed to add the text onto the first line "Monitoring Humidity" at 70%. It does print on the serial monitor but the display doesn"t change at all. I"m hoping some can point out how and where I went wrong.

I"m thinking, Do I have to rewrite the whole lcd.print paragraph a 2nd time, one for each possibility of the if statement? From what I"ve read so far the way I have it written should work, "if, turn led, else do nothing carry on with the program", the else doesn"t need to be there. So the flow seems logical to me.

Oled Arduino Display has been available at the following shops. For the best Oled Arduino Display deals, price and stock refer to the list of products and prices above in Lowpi.

Lowpi will tell you where to find stock of Oled Arduino Display in US and the curent price for each shop (MSRP manufacturer"s suggested retail price if available).