arduino lcd displays garbage factory

The lcd.clear function is slow and can lead to screen flicker especially if done every time through loop(). Overwrite old data with spaces, reset the cursor position and print the new data and only update the screen when the data changes will help prevent flicker.

Hi, i have and LCD 16x2 connected to my Leonardo. I works properly with all the examples son the connection is ok. But I add the LCD to another sketch and it"s just showing garbage, and i have no idea why. I just want to show "Writing:" in the first row, and the variable nombrearchivo in the second row. All of this works using serial, so my only problem is the LCD.

Troubleshooting Code Problems: Start with a known good code base. Many times, pin port directions or the pin assignments have errors. One good technique is to write test code that toggles only one of the control pins, then verify that the correct pin at the LCD is toggling. Repeat this for each of the other pins. This exercise checks the signal path from the code all the way to the LCD.

If it is a serial LCD with a stream-style interface (CFA-632 or CFA_634) check to make sure that the baud rate set on the module matches the baud rate in your code.

Whether it is bringing up a new design, finding a new display for an existing design, or even getting an LCD to work on a Raspberry Pi or Arduino project, we are here to help.

Marlin deals with a variety of different displays and needs to display a lot of different languages in different scripts on them, within their capabilities. The system described here solves some of the related problems that need to be overcome with in a limited environment.

On all these displays you can define 8 custom symbols to display at once. In Marlin these characters are used on the Boot Screen, and on the Info Screen for the Bed Temp, Degree symbol, Thermometer, “FR” (feed-rate), Clock, and Progress Bar. On the SD Card listing screens some of these characters are re-used again for Up-level, Folder, and Refresh.

Graphical displays provide complete freedom to display whatever we want, so long as we provide a program for it. Currently we deal with 128x64 Pixel Displays and divide this area into ~5 Lines with ~22 columns. So we need monospace fonts with a bounding box of about 6x10. Until now we’ve been using a custom Marlin font similar to ISO10646-1 but with special symbols at the end, which made ‘ü’ and ‘ä’ inaccessible at 6x10 size.

The upshot of all this is that on Western displays you’ll see a ‘~’ while on Cyrillic an “arrow coming from top - pointing to left” (which is quite the opposite of what the programmer wanted). The Germans want to use “ÄäÖöÜüß”, the Finnish at least “äö”. Other European languages want to see their accents too. For other scripts like Cyrillic, Japanese, Greek, Hebrew, … you have to find totally different symbol sets.

The Japanese translator dealt with two scripts, introducing a special font for Graphical Displays and making use of the Japanese extended character displays. Thus he ended up with two pretty unreadable language.h files full of ‘\xxx’ definitions. Other languages either tried to avoid words that included special symbols or just used the basic symbols without the accents, dots… whatever.

Make output functions that count the number of chars written and switch the font to Marlin symbols and back when needed. (ultralcd_impl_DOGM.h) (ultralcd_impl_HD44780.h)

Make three fonts to simulate the HD44780 charsets on dogm-displays. With these fonts the translator can check how the translation will look on character-based displays.

If you make extensive use, your file will look like language_kana.h and your language file will only work on one of the displays (in this case DISPLAY_CHARSET_HD44780 == JAPANESE).

If you want to make use of more than a few symbols outside standard ASCII or want to improve the portability to more types of displays, use UTF-8 input. Which means defining another mapper.

Mapper functions will only catch the ‘lead-in’ described in the mapper’s name (e.g., C2C3). If the input doesn’t match, the mapper will output a ‘?’ or garbage.

In short: Choose a mapper that works with the symbols you want to use. Use only symbols matching the mapper. On Full Graphic Displays all symbols should be fine. Using the graphical display, you can test for bad substitutions or question-marks that would appear on character displays by defining SIMULATE_ROMFONT and trying the different variants.

If you get a lot of question marks on the Hitachi-based displays with your new translation, maybe creating an additional language file with the format language_xx_utf8.h is the way to go.

If there’s no existing mapper for your language then things get a bit more complex. With the Hitachi-based displays you can’t make something useful without a matching charset. For graphical display… let’s take the example of Greek: Find a matching charset. (Greek and Coptic)

The length of strings (for menu titles, edit labels, etc.) is limited. “17 characters” was a crude rule of thumb. Obviously 17 is too long for a 16x2 display. So, language files are free to check the LCD width and provide shorter strings in the following manner:

On 16x2 displays, strings suited to a 20x4 display will be chopped to fit. So if shorter string isn’t provided, at least make similar strings different early in the string. (‘Someverylongoptionname x’ -> ‘x Somverylongoptionname’)

To find out which character set your hardware uses, set #define LCD_LANGUAGE test and compile Marlin. In the menu you’ll see two lines from the upper half of the character set: JAPANESE displays “バパヒビピフブプヘベペホボポマミ”

If you get an error message about “missing mappers” during compilation - lie about your display’s hardware font to see at least some garbage, or select another language.

LCD_LANGUAGE: The LCD language and encoding to compile in. For example, pt-br_utf8 specifies Portuguese (Brazil) in UTF-8 format with a mapper. For a faster, lighter, but non-accented translation you might choose pt-br instead.

MAPPER_ONE_TO_ONE: Most character sets on graphical displays (including SIMULATE_ROMFONT) map the character index directly to its position in the upper half of the font. This is possible for character sets that have only 2 contiguous pages of Unicode containing all the special characters. Other mappers use logic or a lookup table to locate the glyph.

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.

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/

I spent more time today trying to use this to help in debugging an Arduino, than if I would have just soldered on a JTAG connector, installed linux, and used that.

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.

I"m using usb->rs232 adapter for data and an open wire usb cable for power and am getting garbage on all baud rates using code and putty. Am I doing something wrong?

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.

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.

I used a few of these in my IRcombat laser tag game with my arduino duemiloves and love them. I also used the Red and Black. I like the white and black better outdoors and the red/black indoors. I just wish I could figure out how to send the reset code to them. I know how to clear and change brightness in code, but the ctrl+ command boggles my mind. A few of them have to be unplugged and plugged back in to work after power on because of this issue. Not worth replacing them yet.

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.

I received mine just yesterday and hooked it up. It definitely works, but it occasionally "wigs out" in various ways. I set my own splash screen, which worked fine the first couple of times. The third time I powered it on I got a screen with one line of white blocks and one blank line. It has lost the baud rate setting on me several times. Sometimes I get reverse video garbage characters for some reason.

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 is a in-depth guide for the DS18B20 temperature sensor with ESP8266 using Arduino IDE. We’ll cover how to wire the sensor, install the required libraries, and write the code to get the sensor readings from one and multiple sensors. Finally, we’ll build a simple web server to display the sensor readings.

After installing the required libraries, you can upload the following code to the ESP8266. The code reads temperature from the DS18B20 temperature sensor and displays the readings on the Arduino IDE Serial Monitor.

After uploading the code, open the Arduino IDE Serial Monitor at a 9600 baud rate. You should get the temperature displayed in both Celsius and Fahrenheit: