Prototype 3

More progress on the prototype DRO. Buttons are now working – Axis reset and Measurement toggle.
Also added a startup config option to allow default metric/imperial measurement and reverse axis options.

New board has been designed and back from the PCB house. I have added a header for S/W SPI port and select
lines in case anyone whats to use standard 7-segment displays via MAX7219/MAX7221 drivers.

display-p3 Display-p3-2

The board uses a surface mount TQFP ATMEGA328P. ICP and FTDI headers provided for Bootloader/Prog.
I managed to load the bootloader using either an UNO as a programmer or using a cheap USBASP programmer board.
Both worked. The board is treated as a Arduino Uno and must be set as this in the Arduino ADE for either bootloading or programming via FTDI.

Font still needs updating for the OLED display.

Sensors have been mounted in the aluminium cases I made earlier. I have potted these in epoxy resin and added armoured cable.

The top of the AS5311 sensor sits above the resin and casing by a small amount.


My small Taig mill will be the first recipient of the DRO. I’ve spent a few days making the mounting brackets for this.
Here’s the Z Axis sensor mounted and ready to go. The magnetic strip is mounted in a 16mm square aluminium U channel.

I’m in the process of mounting the X and Y sensors.


Next step is to mount the display board. For this I plan to mill the case from a solid block of one inch thick aluminium.



  1. Hi Ithink you do beautiful work and have very good ideas. you stated that you would post the pcb schematics and code in 2016 and I looked all over your website but no luck I can’t find any daten for the DRO system. I thank you very much for the placementt of the data. I would use the data because i cannot program at all and very much would like to build your DRO System.

    Liked by 1 person

  2. Hello , I have been wanting to make a DRO for my machines for quite a while now & I just found this site again after a year . I looks to me like the nicest DIY one I have seen . are you selling the plans for this project ?
    thank you

    Liked by 1 person

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