- Digital Readout - 


MagDisplayPhoto320x240 MagDisplay320x240


The DRO project realizes a digital readout (DRO) for mills, lathes or other devices using linear magnetic strips with a magnetic pole length over both poles (N and S) of 2 mm. It contains the sensor PCB that is based on an Austria Microsystems AS5311 encoder chip and a 3 channel display PCB that is based on an Atmel ATMega8 microcontroller for each channel. 

Magnetic strips are cheaper and smaller but a little less accurate than glass scales. On the other hand, they are more accurate, more reliable and faster than digital caliper based readouts. 

Basic features

  • DRO with 3 fully separate display blocks with 7-segment LED displays - Six digits plus sign. It is possible to build the display for 1, 2 or 3 channels as the display blocks are fully separate. 
  • Maximum resolution on display is 0.001mm. Option to round values to 0.005mm steps. Display shows inch or metric values. 
  • Overall accuracy is strip-dependent. The resolution of the Austria Microsystems AS5311 is 488nm. 
  • Two push buttons per channel to zero the scale and to switch it to relative mode. 
  • Selectable lathe mode doubles the distance shown. 
  • Simple menu to set different values that are stored in the controller EEProm.

Included in the project files

All files and sourcecode needed to build the DRO are included in a single ZIP file. 

Further information

Display unit

Sensor unit



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