‡: the colors of the jumper wires on the cable I made.
pins 6,8,and 10 are a nice block on the outside row, skip two down.
Results (WiP)
I've successfully connected with:
minicom
octoprint
pronterface(s)
All at 500k baud and with the 3.3V line left dettached.
I only had success after having the Pi and the Mini share ground off the same power supply.
The connection succeeds near-instantly every time and seems, so far, much more stable.
I've hacked pronterface to ignore the non-gcode and completed prints without a glitch.
serial_init
SetSysTick
RetrieveSettings
port_init
LED_ON
ENDSTOP P TRIGGERED
ENDSTOP P TRIGGERED
setup
���Ӻ�����������Һ����Һ���
The garbage on the last line is fbd3d9d3bad3d4c1d2d4c5c4fdfbd6c5d2bab4b0fdfbd2bad5c4fd in hex.
Doesn't look very random. They're all really high.
Flip the first bit of each byte and you get ASCII back. Following setup is {SYS:STARTED}{VER:40}{R:UD} which looks like the codes mentioned here and reported there.
I also see FBD3D9D3BAC2D5C9CCC4FD which is SYS:BUILD} a bunch. I don't know what happened to the leading '{'.
There are three red flags (herrings?) that will probably come up:
UART: undefined as reported by set serial above.
After loading the AMBA PL011 UART driver, the console will print uart-pl011 20201000.serial: could not find pctldev for node /soc/gpio@7e200000/uart0_pins, deferring probe
When accessed, the console will print uart-pl011 20201000.serial: no DMA platform data
These all seem to be expected on a Pi and won't block connecting.