Saturday, 11 May 2013

Humble Pi

My  main reprap printer uses the same, none standard,  control electronics as some of nophead's earlier printers. It differs from the standard reprap gear in that the firmware is a slave to the PC. All the gcode decoding is done by the PC, and simple move, temperature, extrude commands are sent to the reprap electronics.

This is great in that if I want to change the Z height, or adjust the filament dimensions or temps. I simply edit a Python script.
Also, the PC communicates with the control electronics over ethernet, so the USB timing issues just don't occur.

To keep the embedded code simple a static IP address is used. Mine is set to and it works great.

Now the arrival of my Mendel90 means that I have to make a USB connection to the Melzi controller every time I want to do a print. This is a pain as I don't have a PC near where the Mendel90 is.

I decided to try the Raspberry Pi print server. It's great. I simply TightVNC into the Pi, and run Pronterface from there.

So today, I started a large 6 hour print at 10am. Around four PM I think 'It's about time I got that Raspberry Pi running' so I plug everything in. As the Pi powers up, the main printer halts with about 1 layer to go and just sits there spewing plastic. WTF!

Of course, with inevitable fate I'd set the Pi to have the same static IP as the first printer and the bloody thing lost its comms. to the host software.

1 comment:

graphmastur said...

I'd like to suggest as a possible replacement. I believe it is easier than running a vnc over to the raspberry pi.