A few weeks later, and the PCBs have arrived. Unfortunately they weren't matte-black, as I originally ordered from @Elecrow, because I have panelized them, and apparently that is not allowed with matter-black — but they had no problems when I asked to change the color to red.
I tested how the angled headers as SMD pin headers work, and that was reasonably good:
(I included a module with a 0.96" display that I'm going to use here, for scale.)
The second attempt actually went much smoother, and I have a good technique of soldering them without too much work now, so I consider that experiment a success.
Next, I programmed an attiny24, soldered it in place, soldered all the passives, and added a display that, for now, I just desoldered from some module (I have proper, white, displays on order). A quick MicroPython script to test the display:
import machine spi = machine.SPI(1, baudrate=1000000) cs = machine.Pin(15, machine.Pin.OUT, value=1) dc = machine.Pin(12, machine.Pin.OUT, value=0) def write(data, command=True): cs(0) dc(not command) spi.write(data) cs(1) write( b'\xAE' # display enable = off b'\x8D\x14' # charge pump = enable b'\xAF' # display enable = on b'\x20\x02' # address mode = page b'\xB7' # page = 7 b'\x00x\x12' # column = 32 ) write( b'\xFF\x0F\xFF\x0F\xff\x0f\xff', False )
and several hours to fiddling with the passives and connections, until I figured out that the flex cable in the display I have is broken and only works in a certain position:
But at least I confirmed that the display is working.
I'm still waiting for the buttons to arrive — it's been two months already, since I ordered them for #PewPew Mini — but I hope they will arrive Really Soon Now™.