This Arduino Shield Offers a Less Expensive, More Compact DRO for Milling Machines

Digital position readouts (DROs) are almost a necessity for milling machines. The numerical display shows you the position of the machine elements, such as the X and Y position of the mill table and the Z-axis position of the cutting tool. Unfortunately, commercial DROs are expensive and bulky. Luckily, StudioBelow has a streamlined option with its new DRO for milling machines.

The three-axis DRO has all the essential features of commercial variants but is compact, measuring only 90mm x 150mm. Its polar coordinates mode offers a wide variety of tasks that are normally done by non-intuitive features on commercial devices. It also has selectable reference origins, which are more efficient than the standard ABS/INC feature of most DROs.

System configuration – axis sensors PPI, axis direction inversion, decimal points per unit – can be sent via serial using a GUI made for Windows or using a serial terminal. The data is stored in non-volatile memory.

Specs:

• Eight 0.56" digits display per axis
• Quadrature optical encoders interface (RJ11 sockets)
• Two independent reference origins
• Axis zeroing per origin
• mm/inch units
• Cartesian/Polar coordinate system representation
• 50 points memory
• Encoders input filtering
• Recalculation of display values at 25Hz rate
• Built as a shield for the Arduino Uno
• Adjustable display brightness
• Hardware encoder signals XORing for more accurate interrupts utilization
• Powerful MAX7219 display drivers
• Fast, optimized arithmetic manipulations for real-time polar coordinates conversion

For $160, you'll get the compact DRO, which comes with an assembled board including a pre-programmed MCU board. Seems alright to me. You'll have to supply your own 5V power supply though. Get all the details here.