I am trying to build a small weather station. Along with common sensors, I am using a Waveshare 128x128 OLED display with u8g2 library. My LCD init code looks like this: U8G2_SSD1327_WS_128X128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/27, /* data=*/5, /* cs=*/26, /* dc=*/25, /* reset=*/2);
I have tested the project on breadboard, and it seems to work well. Upon putting the same on a prototyping pcb, it doesn't work anymore. The display flickers and then shuts down.
I am using a power-bank to run the project, so no apparent issues with AC coupling as such, what I think. I cannot still get it to work. I am using ESP32-WROOM-D board for this. Please help!
In my opinion, it could be a soldering error. Possibly a "cold joint" or most likely a short. Very difficult to spot with this type of proto board.
Personally, once I had it working on breadboard, I would probably use stripboard, or maybe "perma-breadboard" or whatever it is called. I would keep the layout and wiring of the circuit as close as possible to the breadboard circuit to reduce the possibility of errors.
Indeed, everything runs off the 3.3V rail. I retouched the solder joints too. I had doubts regarding the overly long exposed reset wire, so I experimented by adding a pull down resistor to ground, but still no luck. I checked the draw, it was still in 68-110mA range, so probably no short. Maybe my wires are too long, but I don't know. I think I am going to tear this one apart, rebuild ensuring minimal routing distance for the OLED wires. Any other hints please? Thanks!
I would suspect a power supply issue -,looks as though the processor board is powering everything - is that exactly the same as when you breadboarded it ?
I would not power all that stuff from the board , it could be the on board regulator is shutting down . Check the voltages .
Failing that the only other thing is a board error .
Bit late now , but it’s best to check each part when it’s fitted , that it works , then add the next .
I think you are kidding yourself. If it worked on a breadboard, how much shorter do the wires really need to be?
Your soldering looks a bit blobby but it's hard to tell that there is really anything wrong with it. Those proto boards are really horrible - which excuses a lot of the soldering. And they are not even particularly cheap. Getting proper PCBs made will save you lot of stress, even if you just chuck out the spares. At least you have a working prototype to start with.
Agreed.....
The forum is really good, and the service and quality from JLC is excellent. I have given spare boards to the local Scouts. Your project looks like it will fit on a minimum order board.
