- What a surprise it was to try and load firmware! First I had to choose Marlin over Sprinter (mot much of a choice since, as best I can tell, the LCD support is much better in Marlin.) Hilarious how many web sites state 'load it up in the Arduino, hit upload and enjoy silky smooth printing.' Ha! Configuring Marlin is a mess. There are a freaky huge variety of defines to configure.
- I got the LCD to work for a little while and then it began refusing to do anything but display black bars across the 1st and 3rd rows. I've got at least 20 hours in troubleshooting so far with no joy. I hooked up my lovely little OpenBench Logic Sniffer, and can see that it's getting signals, but nothing that makes any sense. I hooked the lcd directly to the mega and ran LCD test code which worked great, so I know it's not the LCD panel. The panel is essentially wired directly through to the arduino, so I'm stuck with thinking it's something deep in the firmware config. I've tried many dozens of config settings, but nothing changes it at all.
- Even without the LCD, the RampsTestCode happily moved all the motors, so I know the board is working. I got Pronterface to move the motors, kind of. It will move right, but not left. Or it will move two jogs forward and only two jogs back, It complains that the end stops are firing, but none of the end stop inversion settings make a difference. Changing nothing, ReplicatorG works fine, as long as I get a good driver, but there isn't one for Marlin (or Ramps 1.4) directly and so far I've only gotten it to work by telling it I'm talking to Teacup, which may well be hiding grief.
- The endstops that came in my purchased kit have pullups built in (which the Printrbot stops don't.) There are a lot of config settings that talk about pullups on the endstops in Marlin, but I can't tell if they're critical or not.
If anybody has switched out their Printrboard for a Ramps 1.4 and Marlin, I'd love to get some insight regarding the configuration settings that worked for you.