Monkeyprint DLP control board PCB

In an effort to bring Monkeyprint to your DLP printer build I have designed a simple PCB for the control board. This will make it easier to hook up all the components and get your DLP printer going.

The board is based on the electronics hook-up that I used before. It is a single layer design so it is easy to manufacture even in your kitchen.

DLP control board features

The board provides full control over a DLP printer. An Arduino Pro Micro runs the Monkeyprint firmware, coordinates stepper drivers for build platform and tilt mechanism and does lots of other useful stuff.

Photograph showing the Monkeyprint control board in top and bottom view.
The Monkeyprint DLP control board. Simple and effective, it brings together all the necessary components needed to control your printer. It has stepper outputs and end stop inputs for build platform and tilt mechanism, an output for a shutter servo, a camera trigger for time lapse videos and more. Connect it to your PC via USB or to your Raspberry Pi (software coming soon) via UART.

Check out the board’s features below:

  • Serves as connection between off-the-shelve components (Arduino Pro Micro, Pololu DRV8825)
  • Input voltage from 7 to 36 V
  • Reverse voltage protection
  • Switching regulator step down to 5 V with up to 3 A
  • 5 V cooling fan output
  • Connection to Raspberry Pi including 5 V power supply for the Pi
  • 3 end stop low pass filters
  • Shutter servo output
  • Projector control output
  • MosFET camera trigger output
  • Status LEDs & reset switch connectors

Concerning the number of components and the confined space (I wanted it to fit onto the Raspberry Pi 2/B+/A+ footprint), it was hard to get it all together. The spacing is very tight and some wires are needed.

Hook up your Pi!

You can easily attach the board to a Raspberry Pi 2/B+/A+ using M3 bolts and 20 mm PCB spacers. The connector provides 5 V to the Pi and links the Arduino Pro Micro with the Pi’s UART. I’m still working on the software that will run on the Pi, so keep watching for updates on this site…

Photograph of the Monkeyprint DLP control board attached to a Raspberry Pi 2.
Simply connect the board to your Raspberry Pi. The good thing: the Monkeyprint DLP control board will supply your Pi with the necessary 5 V. The software to run on the Pi will be published soon.

New board, new box

I have also adjusted my electronics box design to fit the new DLP control board — it’s much shorter and sleeker now. Also the build quality is superior to the old one since I had a serious talk with the Ultimaker that I use at work… Together with a 60 mm fan it forms a compact control unit for a DLP printer.

Photograph of the Monkeyprint DLP control board inside of it's case on top of a Raspberry Pi 2.
A neat housing can be printed using an FDM printer. Raspberry Pi 2 and Monkeyprint control board are connected via 20 mm PCB spacers. The fan does not only cool the components but also holds the top and bottom part of the case together.

Build the board

The PCB files are in my github. If you download Monkeyprint you will find a hardware folder inside the main directory. It contains eagle files of the board and the schematics and board layout as pdf files.

Simply get the board etched at your local etching store or build it yourself. I use the following procedure:

  • Get the board layout transferred onto photographic film at your local print store. This will result in a superior quality, high resolution exposure template.
  • Cut a piece of photoresist-covered board to size (65 x 56 mm).
  • Expose the board using one of those cheap nail polish curing lamps with only two of the four UV bulbs installed. Duration: 2 minutes.
  • Develop the board using a sodium hydroxide solution (10 g on 1 l water). This will take some seconds at most.
  • Etch the board using  ferric chloride or sodium persulfate. Might take several minutes.
  • After the etching is done, clean off the remaining photo resist using acetone.

You can then assemble the board using the following components:

  • 1 x schottky diode SK54C (40 V, 5 A), 0.27 €
  • 3 x capacitor 100 nF, 0.04 € each
  • 8 x resistor 10 kΩ, 0.10 € each
  • 3 x resistor 330 Ω, 0.10 € each
  • 3 x resistor 220 Ω, 0.10 € each
  • headers 2 x 20 angled, 0.90 €
  • headers 1 x 20 straight, 0.31 €
  • sockets 1 x 56 straight,  ~2 €
  • 6 x jumper, 0.07 € each
  • 1 x MosFet BSS123, 0.15 €
  • 2 x capacitor 100 µF / 63 V, 0.05 € each
  • 1 x capacitor 1000 µF / 35 V, 0.13 €
  • 3 x photo interrupter Everlight TR8102, 0.41 €
  • 1 x Arduino Pro Micro, ~5 €
  • 2 x Pololu DRV8825, ~5 € each
  • 1 x LM2596 step down converter module, ~2 €
  • Some wires, miscellaneous stuff, ~5 €

Refer to the Eagle files for the specific part locations on the board. If you experience problems during the board assembly or operation, please contact me via the comments!

If we consider the costs for the board itself with ~2 € that’s 31.93 € for a DLP control board including the stepper drivers and everything. Not bad, isn’t it?

Where is this going?

Well, the next step will finally be the adaption of Monkeyprint to run as a non-GUI standalone version on the Raspberry Pi. I know some of you are waiting for this and it will be there soon.

So stay tuned and make sure to comment below!

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