i’d searched related topics in the forum but none of them is useful to my situation, also i’m new to this forum, please correct me if i post this thread in the wrong place thanks! my question as follows.
i was going to modified some components and design from og teletype by replacing dip style led and 5v regulator into 78l05(maximum 1.5a output), which could encourge more diyer to handmade monome teletype. also soldering processed by my diy oven so i consider my assembly process were fine, no solder joint or any failure, finally i could download the firmware to mcu successfully without error message.
one additional thing, i’m using at32uc3b0256 rather than at32uc3b0512 so the command to flash, erase and start will be different from the instructions at monome official website. memory capacity is a little close to its limitation(84%) but still far away from insufficient.
once above is done, i installed the oled display screen to pcba, somehow there’s nothing on it after powering teletype up, just a black screen. i’d measured supply voltage, all of them is stable at 3.3v/5v/-12v/12v without any voltage drop(if the current consumption is too high there should be a voltage drop and heat came out). i haven’t measured mosi, sck, clk with oscilloscope but there’s readable signal in multi-meter, so i guess the peripheral at mcu were still working.
any hints or suggestions for troubleshooting? so far i don’t know what would be the next step to debug.