Open lpflpf889 opened 3 months ago
Hard to tell without seeing it directly, but first guess would be a soldering issue. If you have an oscilloscope or logic analyser you could probe the pins marked MOSI and SCK on the display daughterboard. If the microcontroller is outputting SPI data to the screen you will see activity on those pins. If you don't have an oscilloscope you could use a multimeter to probe the same pins. I would expect a voltage around 1.7V on the SCK pin (as it is a clock signal that is 3.3V for half the time and 0V the other half). MOSI should be slightly less.
Tracing those signals back to the main board and to the microcontroller will possibly give further clues as to where the issue is.
Another troubleshooting path is to check that the microcontroller is working. To do that you would need to download the firmware source code from Github and open the project in STM Cube IDE. With the ST-link connected to the module you can then start debugging the project. If part of the hardware is not working (eg the external oscillator) you will see the application halt in the clock initialisation code.
Sorry if this is a bit vague, but I would need a lot more information to provide decent assistance - higher resolution pictures of front and back would be a good start. Also if you can tell me what test equipment and experience you have I can tailor advice better.
I tested my 8MHz crystal oscillator with an oscilloscope, but it did not start oscillating. The IDE displayed as follows; measured input voltages of -12V and +11.3V using a multimeter. Attached is a picture of my PCB. Still not work,please help me~
<img width="1260" alt="20240607234412" src=https://github.com/dchwebb/Oscar/assets/91143125/c73569f9-3034-4135-a67f-35fce2b5fa0b">
From the photograph it looks like there might be some solder bridges at the top right of the microcontroller. In this area are the Reset line, the crystal and the LCD DC and LCD Reset lines. If it looks like there might be bridges you can use the continuity mode on the multimeter to test for shorts. If there are solder bridges some flux and desoldering braid should be able to clear up.
Another thing to test is the 3.3v power rail - without that the microcontroller won't function.
After assembling the hardware, I flashed the Oscar446.elf firmware directly, but the screen displays as white with no information. What could possibly be the issue here? Is it likely a problem with the bootloader or some other hardware malfunction?