CNC Controller Update

The community has spoken! With their Wallets!

Note the change in title, from the previous two… clearly the words “grbl” and “raspberry pi zero” are now missing from the title.

Thing is, over the last week a lot of new information came to light:

  • The media is now calling the Raspberry Pi Zero a failure, a missed shot, and a design abomination.   The lack of networking support (and no, despite the hype around that post on, an ENC28J60 is not better than sliced bread. Its an old, slow ethernet Phy interface chip that I played with two years ago and still hate… that said, its fine for IoT, not fine for fast streaming websockets to drive a CNC), the need for adapters by using a OTG port, all those left the Favourite Pi, quickly becoming the “it may still have a use case in IoT, because it’s cheap…” Pi…
  • The community wants 4 axis. This had to be the most-replied to comment on my social media this week! Grbl only supports 3 Axis…
    The second complaint in regard to Grbl came from one of my biggest supporters, Mark Carew ( in that Grbl slows down in small cicles (8Bit is so 1980’s right?)Lastly, my own complaint against grbl is the pin and ram limitation of the ‘328p (and then the cost of 2560’s as an upgrade option).  While coding in support for the Trinamic into Grbl (see I had to drop the Enable Steppers pin, to have enough pins for the SPI Chip Select for 3 drivers. sigh. That, and though I have the Trinamic driver in there, I doubt I have space left for the DRV8711 Driver now…
  • Stepper driver support. One of the developers of another project told me that one of the other players is working on a board with SPI drivers too. I know who, I know what. But I am not telling. Point is, a little competition means a) we need to hurry up and get the open design out there asap and b) that firmware support becomes easier – the more players there are, the more boards support the same chips, the more the end user will win (more developers working on code, example settings, etc)  –  it also tells me that the work I started on in Jul 2015 (github log to prove) – was relevant and I saw this coming (;

So what does this mean now?  No more Pi Zero? No more Grbl?

NO.  But it does mean some diversification…

Watch this space! Looks like we are going to support at least

  • Drivers:  DRV8711 AND Trinamic 2660 (and if budget allows DRV8825)
  • MCU:  8bit Grbl, AND 32bit (Smoothieware) (low cost version, and a bells and whistles version)
  • Connectivity: Pi Zero, (Smoothie: USB and LAN8720a Ethernet), AND (ESP8266 Wifi with ESPLink Firmware)

Update on Donors

If you’d like to donate, you can do so from
Having a few more boards in the queue means prototype costs just went up, a lot!

Here’s a list of all the donors on this project so far:

  • Samer Najia – $50
  • Casey Coward – $5
  • Brain Bland – $10
  • Klemen Zivkovic – $10
  • Frankie Graffagnino – $25
  • James K Rivera – $10
  • OpenBuilds Part Store – $250
  • Manual Conti – $5
  • Jeremy Francois – $15
  • Fred LaPlante – $50