“Build an optical RPM indicator for your CNC router with an Arduino Nano, an IR LED/IR Photodiode sensor and an OLED display for less than $30. I was inspired by eletro18’s Measure RPM - Optical Tachometer Instructable and wanted to add a tachometer to my CNC router. I simplified the sensor circuit, designed a custom 3D-printed bracket for my Sienci CNC router. Then I wrote an Arduino sketch to display both a digital and analog dial on an OLED display
A few simple parts and a couple of hours of your time, and you can add a digital and analog RPM display to your CNC router.
Here’s the parts list available for 2-day shipping. You can probably source the parts for less if you’re willing to wait longer.
Parts List:
$6.99 Arduino Nano
$5.99 IR LED/IR Photodiode (5 pairs)
$7.99 OLED display 0.96 yellow/blue I2C
$4.99 Jumper wires
$1.00 30 inches (75 cm) 3-conductor-stranded wire. Can be purchased from your local home supply store (Home Depot, Lowes) in the buy-by-the-foot section
$0.05 220 ohm resistor ($6.99 if you want 750 assorted resistors)
$0.50 Heat shrink tubing ($5.99 if you want a complete assortment)
3D Printed brackets
Arduino IDE (free)
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