Weeny solder bot

Just wanted to show off this little through-hole soldering machine I made, goes by the name 'Weeny' because the whole thing fits in the size of an A4 sheet of paper. It's running on a RaspberryPi ZeroW using my 'weenyPRU' realtime unit that targets the STM32F103C8 (aka blue pill) microcontroller. The firmware and LinuxCNC component was based on Remora, but has been heavily modified to suit my needs and the capability of the lowly F103C8. 

All the parts were made on my big router, also running LinuxCNC of course. I built the router a couple years ago when I knew almost nothing about LinuxCNC so it's a very basic setup, but I learned so much doing this solder bot that I finally understand it all much better now. I was able to set up a decent physical control interface using halui which seemed far out of reach a couple years ago.



I designed the PRU board to keep the wiring tidy, but this could also be done with a regular blue pill, if you enjoy dealing with a huge ball of spaghetti wiring. Here is some info on the board: github.com/iforce2d/weenyPRU
My first PCB design had some errors so right now I'm waiting on delivery of the second version, after I confirm everything is ok I'll add the PCB files to the github page. Here is a video I made that looks at the PRU board:



There is some more discussion about the PRU in the forums here:
forum.linuxcnc.org/18-computer/42276-rem...spi?start=730#280751

Since the PRU is not much more than a blue pill, it's quite cheap. I paid US$42 for 5 boards from JLCPCB (that's with no pins or connectors of course, just the SMD parts), so that's about $8 each, and with a RPi Zero being $20 or less this is a really cheap way to get started with LinuxCNC. The PiZero is ungodly slow to run the GUI at the same time though, which is why I'm running everything 'headless'. Since this solder bot does the same job over and over, I can get away with not using the GUI, but if you did want a GUI you'd need at least a RPi3 to not go crazy.

Apart from the physical halui controls, my linuxcnc-gcode-server is helpful to run everything headless. This lets me enable, home, load programs, run MDI commands etc over a telnet connection. You can find more info on that here: github.com/iforce2d/linuxcnc-gcode-server
And a video demo of that: 


 

didnt see you posted it here, I saw it posted on hackaday this weekend. lookin pretty good.

This might be better as a new thread, but this one was already made so I'll just tack it onto here...

Over the last year I've occasionally been adding new functionality to this 'weenyPRU'. The PC that was running my large router died so now I'm running it with a Pi4 and one of these units. Looking good so far.

The new features are:
- UART control of TMC2209 stepper drivers (set microsteps and phase current via HAL pins, can adjust at runtime)
- XGZP I2C pressure sensor (150Hz), will be used to sense vacuum pressure in my SMT pick-and-place
- DS3502 I2C digital potentiometer, currently using this to control the VFD of my router
- HX711 load cell amplifier (80Hz), will allow my pick-and-place to probe heights

The poor little F103C8 is now looking very busy, not sure if it can be pushed to do much more than this. Here's a scope of some load cell testing: