ascii lcd display price
Mini-Box USB LCD is an intelligent 2x20 character USB LCD display module with InfraRed receiver and keypad interface. This USB LCD display device it"s a true USB HID device (not serial or parallel port to USB emulated) supporting high speed data transfers and easy application developmen without any special drivers needed.
Mini-Box has designed picoLCD with the ease of use in mind reducing the time and money needed for integrators to launch a new product with picoLCD. Our sample applications provides windows and linux platform support with open source code and SDK available.
Mini-Box USB LCD has built in 8x5 dots ASCII character font with 8 used definable characters and provides 8 GPO (General Purpose Output) pins. Internal EEPROM allows firmware upgrading and splash screen definition. On power on Mini-Box USB LCD is able to show up to 10 user defined splash screns with custom timing, order and led/gpo status.
- picoLCD OEM SDK(includes RC5/RC6 decoding functions, Keypad support, LCD display functions and custom widgets like histograms, vumeters, custom characters): picoLCD20x2-SDK-0.1.8.gz
Bought this from Robotshop retailer. Worked right away like a charm. I even changed splash screen to display my software version. However at some point it stopped displaying text, then backlight started spontaneously switching off several seconds after powering on. I connected LCD to different device and started experimenting just sending one command at a time.
ALL 0xFE commands work just fine. I am able to switch display on/off, change between underline and blinking cursor, directly position cursor on screen and scroll screen around. 0x7C commands work too, I can control backlight and turn splash screen on/off. Reset 0x12 also works.
The only thing that does not work is actual text display. I tried all acsii characters at different cursor locations. It seems that something is going on, at least cursor jumps to 2nd line after printing 16 characters (does not move otherwise), except characters are invisible. Note that splash screen still works, with exact text I put there!
My only complaint with this product is the difficulty in mounting. Finally had to drill out the holes to accept 4-40 standoffs. The Eagle files don"t include the complete board so making a screw hole template from the PCB is impossible. Otherwise works fine with my stand alone Atmega 328P using the SerLCD.h and SoftwareSerial.h libraries.
Does anybody know how to do a hard reset on this LCD? While I was uploading my code, I left it plugged into TX, and it doesn"t work anymore. I"m realizing that it probably got spammed with commands and the configuration got messed up. Does anybody know how to reset to factory defaults?
I have the same question. I now have the 3.3v serial enabled LCD (with backpack) and want to use this one for future usage. VDD of 5V can be supplied, but will the TTL work when its getting 3.3V signals from the TX from Netduino?
I"ve put together some python code for sending serial data to these LCD screens. In particular, the code pulls my twitter status and writes it to the LCD. To work with the extra characters, I wrote functions to page the text (vertical scroll) or scroll the text (horizontal scroll). Details are available here: http://dawes.wordpress.com/2009/12/23/twitter-to-lcd/
Is it possible to wire this up in parrellel rather than use the serial function? I ran into a snag and am unable to use the serial function of this lcd? I see the pinouts on the schematic but when wired it doesn"t seem to work.
I"ve created a new splash screen for the Serial LCD, now I want to save it to the Serial LCD memory. So, exactly how do I write a "control-j" to the Serial LCD. I"ve put in the required line to transmit special character 124, but I can figure out how to format the "control-j" line of code. I"ve Googled this for about an hour and can"t find an explanation or sample code anywhere. Here"s my code...void setup() {
I"m not sure if you"re referring to comments on the website, or on your LCD screen. You can contact techsupport@ and they"ll be able to assist you further.
I have used a Labview program for this LCD. When i send character "a", the display is "0". Does anyone having a same problem. How should I troubleshoot this problem.Tq
Has anyone managed to get the PWM backlighting working with an Arduino? I"m trying variations of this and nothing works except the standard On/Off commands using 0xFE as the escape. All my attempts turn the display off but the backlight LED is on full.
Why do I get power out of the VDD port with only RX and GND hooked up? I have a 5V rail that I use to power everything on my board - and when I added this SerLCD I now have a bridge between the arduino power and my 5v line ... which I dont want. Can I add a diode to the VDD to stop reverse voltage from powering my board?
It seems like the MCLR function has been disabled through the config bits. No pullup to Vdd is installed. This makes it really irritating to work with this display. Programming an arduino with this hooked the HW serial port will screw up the display, and without the reset line you have to pull power. A simple solution would just be to wire the PICs MCLR pin to the Arduinos reset line, but this isn"t possible without the MCLR function obviously.
Quick suggestion... It"d be very helpful for some people if you guys added a note in the description pointing people to the correct 3-pin JST jumper wire to be used with these serial LCDs. Two reasons... it"s not clear that the jumper is not included, and you have 3-pin jumpers in your catalog which don"t work with this serial LCD.
I have ported LiquidCrystal library for use with the serial LCD you can look at my code here. Still working on finishing all the documentation. But putting up for now hopefully someone will find it usefull.
I"m also having the same problem after accidentally sending the control character "|" followed by "\", "-", "/" to the LCD as I was trying to animate a rotating bar to indicate a busy status.
The baud rate problem can be solved by writing at 9600, at startup, a "change baud rate" command to the target rate. At worst, the display is already at the target rate and will misinterpret the command and display garbage, at best, it will be set to the right baud rate.
Does the serial version of the display still have the parallel pins available on it? I would like to use the serial access for the most part, but I might need regular old parallel for one project.
Yes you can, but you are limited to only 8 custom characters. First define 8 bytes that will hold your custom character, one byte per line (obviously only the lower 5 bits can be used since this is a 5x8 display). Then decide which character (from 0-7) you want to set. Call this "x". Then do this pseudocode:
I"m surprised that a mechanical drawing is not included in the data sheet. It"s not too hard to measure but seems like a documentation oversight for anyone who wants to integrate the display into a case.
Having ordered this exact LCD myself, I can say that aside from the issue mentioned in my other comment, it looks exactly like the picture. No bulky backpack module, everything is on a single board. Pretty sleek, really.
Hi...noob question. how do i send data on the fly via arduino? it only has 1 connection to tx. i tried using the serial monitor to send something, but it doesnt work...im looking for something which i guess is similar to liquidCrystal->SerialDisplay example.
Nevermind, my own fault. I calculated the wrong offset to the start of the second line when I repositioned the cursor. Although the second line was displayed correctly, the offset was wrong by -32.
The data stream I tapped into once inadvertently changed the backlight level to something less than 100%, and I noticed that the dimmed display had a noticeable flicker.
I have a couple of suggestions for a future version: On the PCB layout, please add a thermal to the ground pin for the user connectors to make it easier to hand solder. Please change the firmware to make it more difficult for a random serial stream to stumble upon a configuration sequence. Maybe pick a non-printable prefix character like ESC instead of the vertical bar. Please make the brightness values more user friendly, like 1, 2, 3, etc. Maybe have an option to make the display scroll when it gets full, instead of resetting the cursor to home and overwriting. All-in-all, a fun little platform. Thanks for using a PIC on this one! I think I may try my hand at writing some new firmware for it. Cheers!
Edit: Got mine fixed. If you checked the soldering on all the terminals, check them again. I also sometimes was getting strings of garbage if I wriggled the terminals on the LCD (I suspect because I was getting a partial connection on the bad terminal). Resoldered and it is working fine now.
Wait, so I get the 3 pins for power and control, but whats with all the other pins on the sides? Can it be used to control another LCD besides the one built in?
The other pins are used if you want to control the LCD without using the serial standard. There"s some tutorials on how to do that with the arduino below. You have more control over what you can do with it, but it takes up more pins on the arduino. If you want to wire it up this way, don"t spend the money on the serial interface, they have cheaper LCD"s that allow you to do it this way, without the serial.
This is20×4 Character LCD Displaywith Blue Backlight ASCII Alphanumeric Character. 20×4 character LCD Display can be Interface with almost All Digital Microcontroller such as Arduino, 8051, PIC, AVR, ARM, MSP, COP8, STM, Raspberry Pi etc. 4x20 Display also used in Industrial Research and Development R&D, Student Hobby DIY Project. About20×4 Character LCD Display: 20×4 LCD is a basic 20 character by 4 line display Blue White Back light.
Utilizes the extremely common AIP31066 interface chipset. You will need 7 general I/O pins (If use in 4-bit Mode) to interface to this LCD screen. Includes LED Backlight. Features of 20×4 LCD Display : Commonly Used in: Student Project, Collage, copiers, fax machines, laser printers, industrial test equipment, networking equipment such as routers and storage devices.SIZE: 20×4 (4 Rows and 20 Characters per Row), Can display 4-lines X 20-characters. Operate with 5V DC, Wide viewing angle and high contrast. Built-in industry standard HD44780 equivalent LCD controller. LCM type: Character, Package Contents: 1 X LCD 20×4.
5V DC 16 x 2 Lines ASCII Character LCD Display With Yellow Backlight Product Description: o LCD display module with Yellow Backlight o SIZE : 20x4 (2 Rows and 16 Characters Per Row) o Can display 2-lines X 16-characters o Operate with 5V DC o Wide viewing angle and high contrast o Built-in industry standard HD44780 equivalent LCD controller o Commonly Used in: Student Project, Collage,copiers, fax machines, laser printers, industrial test equipment, networking equipment such as routers and storage devices o LCM type: Characters ABOUT This is a basic 16 character by 2 line display Yellow Back light . Utilizes the extremely common HD44780 parallel interface chipset (datasheet). Interface code is freely available. You will need 7 general I/O pins(If use in 4-bit Mode) to interface to this LCD screen. Includes LED backlight. Package Contains: 1 X 16X2 LCD.
Displaying ASCII characters on MXN lcd is very easy. Where M represents number of coulombs and N number of rows. You just need to know about the internal structure of character lcds, registers of character lcds and the characters supported by lcd controller. Below tutorial will help you in knowing about the internal structure of lcd.
Normally lcd contains HD44780 controller in them. Hd44780 is responsible for all the communications with external controller and displaying text on lcd screen. HD44780 is designed by Hitachi and it supports 255 characters. Which means you can display 255 different characters on lcd directly through its controller. The supported characters are ASCII, Digits(0,9) and Japanese characters. Refer to data sheet of controller if you want to know about all characters and their address in ROM of hd44780 lcd controller.
Now to display ASCII character on 16×2 lcd simply pass the address of the ASCII characters present in 16×2 lcd controller ROM(read only memory). I did same in my code. Started from the first character and prints all of them one by one on lcd. Some characters are missing in ROM of hd44780 and special Japanese language characters are present on their locations. So some Japanese language characters will also be displaced on lcd. Few characters in ROM are greater than 5×10 font. These characters will not appear on lcd. Their decimal value will be displayed on lcd but they will not appear on the lcd.
NOTE: You will see some spaces and weird shape characters displayed on lcd. Those characters are present in controller of 16×2 lcd that’s why they are displayed on lcd. Some Japanese characters will also be displayed on lcd. All the characters present in lcd controller will be displayed on lcd. Characters present in HD44780 lcd controller are given below. Pic is taken from data sheet of hd44780 lcd controller.
Coming to the project code. On first row of 16×2 lcd decimal values of ASCII characters will be displayed and on second row ASCII characters will be displayed. ASCII characters start from 34 location of the hd44780 ROM location. So in code i started the ASCII characters from 34th location.
Each character will appear on 16×2 lcd for 1 second after 1 second it disappears and the next ASCII character will appear on 16×2 lcd with its corresponding decimal value.
Some more projects on displaying ASCII characters on 16×2 lcd using various microcontrollers. Each project code is open source. You an use and modify it according to your needs.
In this tutorial i am going to print/display ASCII characters on 16×2 lcd using pic16f877 microcontroller. Lcd is interfaced with pic microcontroller in 8-bit mode. Code is written in c language. High tech c compiler is used to compile code and code is written in Mp-lab ide. Interfacing 16×2 lcd with pic microcontroller and displaying characters on lcd is very easy. Only the portion which is little bit complex is how to generate/display ASCII characters on lcd. Well you don’t need to generate ASCII characters they are already present in the 16×2 lcd controller (HD44780) Ram, like other characters and numbers. You just need to know how to invoke the ASCII characters to be displayed on the lcd screen.
If you are new in the field of microcontrollers and lcd’s and don’t know about lcd pin out, working and internal structure of lcd then please go through the following tutorials. They will clear you about the working of 16×2 lcd. You will learn how to display characters on lcd? Difference between commands and data send to lcd? It will also explain you about how to use lcd in 4-bit and 8-bit mode.
The circuit diagram of the project is given below. Port-B of Pic16f877 microcontroller is connected with data pins of 16×2 lcd. It means Port-B is used to send commands and data to 16×2 lcd. Lcd control signals(read/write, enable, register select) are provided using individual bits of Port-D. All the other connections are normal connections applying +5 volts to microcontroller and lcd. You can see the circuit diagram given below. Rs(Register select) is connected to Port-D Pin#6. En(Enable) is connected to Port-D Pin#7. Read/Write pin is grounded. Lcd will always remain in write state since we made the R/W pin ground.
Coming to the code portion, I first include the header file htc.h. If you are using high tech c compiler always include this library, this library is necessary to be included in every project that is going to be compiled with high tech c compiler. It contains the compilers directives etc. Then the frequency of the oscillator is defined which is 20 MHz. Then individual pins of Port-D are defined. These pins are used to provide control signals to lcd. delay() function is used to generate some arbitrary delay where necessary. lcdcmd() function is sending commands to lcd with control signals. display() function is sending data to lcd with control signals. lcdint() function is initializing our lcd(8-bit mode, display on ,cursor off etc).
In the main function two instructions are invoking ascii characters. The instructioni=j/10; wherej is integer(int) and i is character(char). Now when we divide two integers and save result in character(char) variable. The result is stored in ascii format. Sincej is 0 and dividing 0 by 10 gives 0. So icontains 0, ASCII value of zero.
The ascii character 0 is present at address 0x30. To go to address 0x00 negate 0x30 from 0x30. The instruction i=i-0x30; is doing the same job. First i contains 0x30 after executing i=i-0x30 i contains 0x00. Hence we are at starting address of ascii characters. Now increment the address one by one and display the ascii character associated with that address on the lcd screen.
Notethat the ascii characters of the HD44780 controller differs from the standard ascii characters. The HD44780 controller contains ascii characters in the format given on the right side. Some addresses are also void. So don’t get confused when you see the characters like below displayed on your lcd screen.
Total digits in ram of 16×2 lcd are 256. So i decided to display them all. It contains ASCII, numeric, alphabet and special characters(Chinese). Some address are void so nothing will display on the lcd screen across these addresses.
LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications. A 16x2 LCD display is a very basic module and is very commonly used in various devices and circuits. These modules are preferred over seven segments and other multi-segment LEDs. The reasons being: LCDs are economical; easily programmable; have no limitation of displaying special & even custom characters (unlike in seven segments), animations and so on.
A 16x2 LCD means it can display 16 characters per line and there are 2 such lines. In this LCD each character is displayed in 5x7 pixel matrix. This LCD has two registers, namely, Command and Data.
The command register stores the command instructions given to the LCD. A command is an instruction given to LCD to do a predefined task like initializing it, clearing its screen, setting the cursor position, controlling display etc. The data register stores the data to be displayed on the LCD. The data is the ASCII value of the character to be displayed on the LCD. Click to learn more about internal structure of a LCD.
Do you want your Arduino projects to display status messages or sensor readings? Then these LCD displays can be a perfect fit. They are extremely common and fast way to add a readable interface to your project.
This tutorial will help you get up and running with not only 16×2 Character LCD, but any Character LCD (16×4, 16×1, 20×4 etc.) that is based on Hitachi’s LCD Controller Chip – HD44780.
When current is applied to these crystals, they become opaque, blocking the backlight that resides behind the screen. As a result that particular area will be dark compared to the others. And this is how the characters are displayed on the screen.
True to their name, these LCDs are ideal for displaying only text/characters. A 16×2 character LCD, for example, has an LED backlight and can display 32 ASCII characters in two rows of 16 characters each.
If you look closely you can see tiny rectangles for each character on the display and the pixels that make up a character. Each of these rectangles is a grid of 5×8 pixels.
The good news is that all of these displays are ‘swappable’, which means if you build your project with one you can just unplug it and use another size/color LCD of your choice. Your code will have to change a bit but at least the wiring remains the same!
Vo (LCD Contrast) controls the contrast and brightness of the LCD. Using a simple voltage divider with a potentiometer, we can make fine adjustments to the contrast.
RS (Register Select) pin is set to LOW when sending commands to the LCD (such as setting the cursor to a specific location, clearing the display, etc.) and HIGH when sending data to the LCD. Basically this pin is used to separate the command from the data.
R/W (Read/Write) pin allows you to read data from the LCD or write data to the LCD. Since we are only using this LCD as an output device, we are going to set this pin LOW. This forces it into WRITE mode.
E (Enable) pin is used to enable the display. When this pin is set to LOW, the LCD does not care what is happening on the R/W, RS, and data bus lines. When this pin is set to HIGH, the LCD processes the incoming data.
D0-D7 (Data Bus) pins carry the 8 bit data we send to the display. For example, if we want to see an uppercase ‘A’ character on the display, we set these pins to 0100 0001 (as per the ASCII table).
Now we will power the LCD. The LCD has two separate power connections; One for the LCD (pin 1 and pin 2) and the other for the LCD backlight (pin 15 and pin 16). Connect pins 1 and 16 of the LCD to GND and 2 and 15 to 5V.
Most LCDs have a built-in series resistor for the LED backlight. You’ll find this near pin 15 on the back of the LCD. If your LCD does not include such a resistor or you are not sure if your LCD has one, you will need to add one between 5V and pin 15. It is safe to use a 220 ohm resistor, although a value this high may make the backlight a bit dim. For better results you can check the datasheet for maximum backlight current and select a suitable resistor value.
Next we will make the connection for pin 3 on the LCD which controls the contrast and brightness of the display. To adjust the contrast we will connect a 10K potentiometer between 5V and GND and connect the potentiometer’s center pin (wiper) to pin 3 on the LCD.
That’s it. Now turn on the Arduino. You will see the backlight lit up. Now as you turn the knob on the potentiometer, you will start to see the first row of rectangles. If that happens, Congratulations! Your LCD is working fine.
Let’s finish connecting the LCD to the Arduino. We have already made the connections to power the LCD, now all we have to do is make the necessary connections for communication.
We know that there are 8 data pins that carry data to the display. However, HD44780 based LCDs are designed in such a way that we can communicate with the LCD using only 4 data pins (4-bit mode) instead of 8 (8-bit mode). This saves us 4 pins!
The sketch begins by including the LiquidCrystal library. The Arduino community has a library called LiquidCrystal which makes programming of LCD modules less difficult. You can find more information about the library on Arduino’s official website.
First we create a LiquidCrystal object. This object uses 6 parameters and specifies which Arduino pins are connected to the LCD’s RS, EN, and four data pins.
In the ‘setup’ we call two functions. The first function is begin(). It is used to specify the dimensions (number of columns and rows) of the display. If you are using a 16×2 character LCD, pass the 16 and 2; If you’re using a 20×4 LCD, pass 20 and 4. You got the point!
After that we set the cursor position to the second row by calling the function setCursor(). The cursor position specifies the location where you want the new text to be displayed on the LCD. The upper left corner is assumed to be col=0, row=0.
There are some useful functions you can use with LiquidCrystal objects. Some of them are listed below:lcd.home() function is used to position the cursor in the upper-left of the LCD without clearing the display.
lcd.scrollDisplayRight() function scrolls the contents of the display one space to the right. If you want the text to scroll continuously, you have to use this function inside a for loop.
lcd.scrollDisplayLeft() function scrolls the contents of the display one space to the left. Similar to above function, use this inside a for loop for continuous scrolling.
If you find the characters on the display dull and boring, you can create your own custom characters (glyphs) and symbols for your LCD. They are extremely useful when you want to display a character that is not part of the standard ASCII character set.
CGROM is used to store all permanent fonts that are displayed using their ASCII codes. For example, if we send 0x41 to the LCD, the letter ‘A’ will be printed on the display.
CGRAM is another memory used to store user defined characters. This RAM is limited to 64 bytes. For a 5×8 pixel based LCD, only 8 user-defined characters can be stored in CGRAM. And for 5×10 pixel based LCD only 4 user-defined characters can be stored.
Parallax 20 x 4 serial backlit mono LCD display. The Parallax Serial LCDs are very functional, low-cost liquid crystal displays that can be easily interfaced to and controlled by a microcontroller using a I/O pin. Code examples are included for the BASIC Stamp® and Propeller™ chip. The LCD displays provide basic text wrapping so that your text looks correct on the display. Full control over all of their advanced LCD features allows you to move the cursor anywhere on the display with a single instruction and turn the display on and off in any configuration. They support the same visible characters as the BASIC Stamp Editor"s Debug Terminal (ASCII Dec 32-127). In addition, you may define up to eight of your own custom characters to display anywhere on the LCD. Clear 4 line x 20 character display Turn backlighting on or off with a single command Directly supports ASCII DEC characters 32-127 Eight user-definable custom characters Move the cursor anywhere on the display with a single command Baud mode selector and adjustable contrast on the back of the display Power requirement: +5Vdc, 20mA (light off), 80mA (light on) Selectable UART serial baud rates: 2400, 9600, 19200 Dimensions: 60.2 x 98.1mm Operating temp range: -20 to +70°C
Adam74 is a small ASCII terminal intended for hobbyist 8-bit computers. It has a simple, vintage-style interface: 7 pins for 7-bits of ASCII data and another "strobe" pin to tell the Adam74 to add the character to its buffer and display it. Special control characters allow cursor movement, etc. Additionally, inverted text is supported as well.
Who is this for? I imagine the audience would be people tinkering with Ben Eater style 8-bit computers. With a simple ASCII interface, 40 columns and 24 rows of text, it is ideal as an Apple I era computer terminal.
The Adam74 consists of a PCB with a (mounted) 2.8" or 3.2" ILI9341-based LCD display driven by an onboard Teensy microcontroller. Additionally it has a small speaker (beep) and can display 40 columns by 24 rows of text. Jumpers provide additional default configuration possibilities (as an example, displaying amber-colored rather than green text). Software on the Teensy handles text buffering, scrolling — recognizes a set of control codes to position and move the cursor.
In addition, I make use of an optimized library for talking with the ILI9341 (the chip on the LCD display) from Paul Stoffregen available from his GitHub repository here.
Notice that among the globals tft is defined and initialized. This is the object used to reference the LCD display. Also a TextBuffer instance is created.
In addition to defining GPIO pins, setup() most importantly defines an interrupt to be executed whenever the ASCII_STROBE goes high. This interrupt (strobe_interrupt()) is how the Adam74 is alerted to new ASCII data on the ASCII bus.
The code has a kind of ring buffer for holding incoming ASCII bytes and buffer_read and buffer_write point to indicees within the buffer indicating where the last ASCII byte was written to and where within the buffer we have last read from.
And so the loop() function checks if buffer_read and buffer_write are out of sync. If they are, an ASCII byte is read from the buffer and processed (handleCharacterInput()). Additionally, loop() handles flashing the cursor at a specific interval.
I decided to use the high bit (bit 7) of the char representing the character to display to indicate whether to invert the charachter when displayed. This is a bit of a hack that saved me having to have a more complex structure to keep track of which characters are inverted and which are normal. So you"ll see me masking or muxing 0x80 with the character from time to time in the code.
I am not a fan of state machines on output devices like this since there is no way for the caller to know the state of the Adam74. Nonetheless, to handle escape sequences that are popular with terminals I had to make a consession. The default state (ASCII_STATE) just grabs ASCII characters from the seven ASCII pins and pushes them to the display. However, if an escape character arrives, the Adam74 will ESCAPE_STATE and a rather dodgy and incomplete implementation in handle_escape_state() tries to handle the characters that follow.
This was about the best font I could find that was legible when very small (to get all of 24 rows by 40 columns on a 320 x 240 display the font must be legible at only 9 pixels tall and 7 pixels wide).
The pins across the top row are the seven bits of ASCII (D6 to D0). The Strobe pin is how you indicate to Adam74 to ingest the 7-bit ASCII value. Adam74 indicates it is busy with the next pin, BSY. The final pin is VCC: expected to be 3.3V to 5V.
To interface to your device you supply +3.3V to +5V to VCC and connect to GND. Then connect wires to, at a minimum, the ASCII pins and STR (strobe). Set high or low the ASCII pins (D0 to D6) representing the character you wish to display on the Adam74 and then trigger the strobe by pulsing STR for 10 or so milliseconds. The character should appear on the display.
I implemented, and in some cases redefined, a number of the control codes. As you may know, the first 32 ASCII characters (fully one-quarter of the 7-bit ASCII range) are non-printing "control codes" with names like "bell", "form feed", "file seperator", etc.
To add more functionality some of the other control codes that did not have a clear utility were repurposed for Adam74. Start of Text (
I provided three jumpers on the back of the Adam74. Currently only JMPR0 is implemented. Jumpering it will cause the Adam74 to boot to display amber(ish) colored text rather than the default green.
To generate the images seen in the photos here, I wrote a simple test app on a second Teensy to send ASCII characters to the Adam74. The code to send an ASCII character looks like this:
As you can see, it is a simple matter of setting high or low the pins corresponding to the ASCII bits and then follow that by bringing the STRB pin high and then low. The software on the Adam74 looks for a rising edge on the STRB pin. That will trigger the Adam74 to scoop the ASCII bits off the bus and display the character.
I wish scrolling were faster. I have experimented briefly with ILI9341 hardware scrolling but if I recall correctly, I could not get it to scroll vertically. Without hardware scrolling, all 40 x 24 characters have to be redrawn to the display when scrolling happens. This performance bottleneck in fact was why I went with the Teensy 4.0 rather than one of the less expensive but slower Teensy models.
The MDS100-BW is specially designed to allow a host computer board, a master PLC or a PC to display alphanumeric characters on its backlit 4 lines x 20 characters per line LCD display via RS485 bus.
You can connect up to 255 MDS100-BW together to a master PLC such as the Nano-10, FMD-Series or F-Series to a host PC. Each MDS100-BW can be programmed with a unique ID between 01-FF, and the master PLC is able to select which MDS100-BW to display what text simply by sending an ASCII string that includes the ID information of the display. Hence the MDS100-BW is ideal for implementing multiple remote displays for a host computer.
MDS100-BW comprises a daughter board (the “control board”) that is plugged onto the back (“piggy-backed”) of a high constrast, black characters on snow white background, 4 lines x 20 characters LCD module. The LCD module is rated for industrial temperature range of between -20oC to +70oC (-4oF to +158oF), making it suitable to be installed in some outdoor applications. The control board may be removed during installation of the LCD module but care must be taken to plug it back with all the pins correctly aligned before turning on the power, otherwise the LCD panel and/or the control board may be severely damaged.
We come across Liquid Crystal Display (LCD) displays everywhere around us. Computers, calculators, television sets, mobile phones, and digital watches use some kind of display to display the time.
An LCD screen is an electronic display module that uses liquid crystal to produce a visible image. The 16×2 LCD display is a very basic module commonly used in DIYs and circuits. The 16×2 translates a display of 16 characters per line in 2 such lines. In this LCD, each character is displayed in a 5×7 pixel matrix.
Contrast adjustment; the best way is to use a variable resistor such as a potentiometer. The output of the potentiometer is connected to this pin. Rotate the potentiometer knob forward and backward to adjust the LCD contrast.
A 16X2 LCD has two registers, namely, command and data. The register select is used to switch from one register to other. RS=0 for the command register, whereas RS=1 for the data register.
Command Register: The command register stores the command instructions given to the LCD. A command is an instruction given to an LCD to do a predefined task. Examples like:
Data Register: The data register stores the data to be displayed on the LCD. The data is the ASCII value of the character to be displayed on the LCD. When we send data to LCD, it goes to the data register and is processed there. When RS=1, the data register is selected.
Generating custom characters on LCD is not very hard. It requires knowledge about the custom-generated random access memory (CG-RAM) of the LCD and the LCD chip controller. Most LCDs contain a Hitachi HD4478 controller.
CG-RAM address starts from 0x40 (Hexadecimal) or 64 in decimal. We can generate custom characters at these addresses. Once we generate our characters at these addresses, we can print them by just sending commands to the LCD. Character addresses and printing commands are below.
LCD modules are very important in many Arduino-based embedded system designs to improve the user interface of the system. Interfacing with Arduino gives the programmer more freedom to customize the code easily. Any cost-effective Arduino board, a 16X2 character LCD display, jumper wires, and a breadboard are sufficient enough to build the circuit. The interfacing of Arduino to LCD display is below.
The combination of an LCD and Arduino yields several projects, the most simple one being LCD to display the LED brightness. All we need for this circuit is an LCD, Arduino, breadboard, a resistor, potentiometer, LED, and some jumper cables. The circuit connections are below.
Ms.Josey 
Ms.Josey