Serlcd Serial LCD LCD-09568 printing line one and three with blocks

Components & Accessories Displays
1

Hi everybody,

I’m having an issue with a serial enabled LCD display which I have had laying around for a little while in my parts storage.

The display seems to now be discontinued but its a 20x4 LCD which connects to just the serial TX line of your microcontroller.

I was using the display as part of a debugger and programmer for an embedded project using the AtMega328p microcontroller. At first the programmer was working perfectly fine and I was able to use it to completely test and debug the project in development. However, if seems to have died after using the burn bootloader option in the Arduino IDE while attached to the circuit.

After this when powered on I dont get to see the usual splash screen rather it simply displays line 1 and 3 filled with black squares, this suggests that the LCD is not initializing and something has happened to the firmware.

You can see the state here:

IMG-20201122-150147.jpg5120×3840 2.19 MB
https://i.ibb.co/8NVTrjb/IMG-20201122-150147.jpg

I have confirmed that the fault is with the LCD and not the program by switching to a different albeit identical LCD which I cannibalized from a previous project as shown here:

IMG-20201122-151022.jpg3648×2736 1.31 MB
https://i.ibb.co/Mf1qTd8/IMG-20201122-151022.jpg

I’m told that this “could” be a symptom of the microncontroller on the LCD being reprogrammed while programing the target UC while the LCD is connected. This is of course good news as it should indicate that its possible to re-flash the UC on the LCD with the correct firmware and once again have the ability to resume work with the debugger while simultaneously keeping my LoRa which is currently in pieces providing the LCD for this project alive.

https://diyodemag.com/projects/lora_weather_station

So my question is as follows:

Is there a way to save the LCD by re-programming it with the correct firmware?

Is there someplace I can find this firmware?

Is there instructions for installing this firmware?

Can someone be so kind as to point me in the direction of the answers?

Kind regards,

Johann

2

Hi Johann.

The older PIC based LCDs had issues when connected to a pin that “random” data was flowing on and it would somehow corrupt the firmware on the LCD. Sometimes you can recover them by sending them some specific commands but usually you need to reflash the firmware.

Check the troubleshooting section for the old hookup guide at the link below for help in recovering the display. The HEX files containing the original firmware are also on that page.

  • https://learn.sparkfun.com/tutorials/pi … leshooting

    • If it’s not recoverable for some reason, the [newer version of this display uses an AVR micro controller and is immune to the bricking problem the PIC based displays had. They also can be sent data over UART, SPI and I2C and have a lot of firmware enhancements. :slight_smile: The only drawback to the new displays is that they are 3.3 volt logic only so if you have 5 volt logic, you’d need a level shifter.](https://www.sparkfun.com/products/16398)