Renoir's RepRap Arduino Mega Shield

by renoir, published

Renoir's RepRap Arduino Mega Shield by renoir Jun 9, 2010


Liked By

View All

Give a Shout Out

If you print this Thing and display it in public proudly give attribution by printing and displaying this tag.

Print Thing Tag

Thing Statistics

5576Views 4365Downloads


I've been working for a couple of weeks on a RepRap Arduino Mega shield. I've got a mix of early generation 2 electronics, a few home-made single sided generation 3 stepper boards, and old arduino with a screw-terminal shield and a brand-new arduino mega.

I designed myself a version of an arduino mega shield to connect the gen3 stepper boards using the 10-pin IDC cables, and it might be useful for anyone transitioning between generations of electronics. Features:

  • Single-sided for PCB for easier home-made boards
  • 5 stepper driver headers - x,y,z,a,b - should match existing gen3 electronics.
  • (future-proof?) UI interface header that *should* match gen4 electronics.
  • Heater 10-pin IDC (to plug in MOSFET driver board later) - should be able to drive a reprap setup with 1 or 2 extruders/ heated bed without an additional extruder board.
  • I2c header as per standard boards
  • Optional extra 3-pin headers for digital in\out and analog in : +5v, GND, and data pin. This makes it easy to add temperature sensors, kill switches, extra limit switches, etc (I'm only using the min endstops).

You can treat this as more of a prototyping board, and solder as many headers/pins as you need: I bought a dozen 50-pin headers, so I filled mine up. I'm only expecting to use one or two of the analog inputs as temperature sensors for now.

NOTE that the +5v/Gnd/Signal headers for the digital and analog pins are directly connected to the internal arduino 5V supply. DO NOT run anything major off these headers. I was only planning to add simple data switches (digital input from high/low), simple thermistor circuits (Analog input) and potentially a small servo (9g micro servo) off these I/O pins - so I didn't pay much attention to them. If you are running any further circuits, use a separate power supply! (all RepRap boards have separate 12v PSU headers anyway).


My build went well. I 'tinned' the copper pads (using some plumbing flux and a tiny bit of solder), which made the soldering a bit easier. Using a tip (from ladyada?) I converted some standard header pins to some through-pins by pushing them through using the flat on a pair of pliers, three or 4 at a time.

Once I'd lengthened the pins, I could put them through from the top of the board into the arduino and check the alignment. I left the pins partially pushed in to maintain the position, and soldered a single pin from each row.
This held them in place when I removed the mega and soldered the rest.

Top Tip : apply the silkscreen layer before you solder the board up. I didn't and had to write all my pin numbers on with a sharpie.

Some pictures of my build in progress:

If you're looking for the arduino mega shield, pins only, I've got some eagle files here:

Updated with thicker traces and ground plane, and 0.3mm centre drills.
Should be easier to home-etch.

All Apps

Upgrade this Thing with Thingiverse Apps

No results.

I would always draw in a bunch of capacitors on all the supply lines near the connectors. If you dont need them, lucky you, but it never hurts to have a stable and reliable supply, especially since the bot does have electronics that tend to generate a lot of noise and interference.
Just a small advice. :)

Good advice. I'm not an electronics expert :-).

As far as it goes, most of the IDC headers are supplying signal data - from the arduino pin to ground, so I assume they wouldn't need smoothing caps.

The extra pin headers, with +5v/Gnd/signal lines, are piggybacking off the arduino 5v feed - so should not really be used for supplying any externa
l circuits. I'll add a note to the description. I was only planning to use them for simple data switch lines and simple thermistor sensor circuits, so I didn't pay too much attention :-)

Thanks for the advice