Lathe DIY Tachometer and Stroboscope Part 1

I am starting a new project of adding a stroboscope and a tachometer to the mini lathe. In this video I show the first step of the project and that is adding the sensor board to the lathe to get the position of the spindle. Today I created the SVG patterns for the mount and also for the encoder wheel, cut them out on the Glowforge laser cutter, and assembled the sensor board that uses an IR LED and photo transistor. All in all with just a little debug on the sensor and a small tweak to the mount and encoder wheel the project went very well as you can see from the video.

The sensor board is very simple with just 4 components, it consists of an IR LED in series with a 390 Ohm resistor between 5V and ground. A 27K resistor connected from 5V to the collector of a photo transistor with the emitter connected to ground. The signal pick off point is at the collector of the phototransistor.

I added heat shrink around the LED and photo transistor to minimize reflected light.

The base code I setup for use with an Arduino LCD shield. Signal input on digital pin 2

Here is the Arduino tachometer code if you want to play around with it:

#include -LiquidCrystal.h- Cannot have brackets in comments, REPLACE - marks with angle brackets
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

long int HighSidePW;
long int LowSidePW;
float PulseWidth;
const int inputPin= 2;
float frequency;

void setup()
{
pinMode(inputPin, INPUT);
lcd.begin(16, 2);
}
void loop()
{
PulseWidth = 0;

HighSidePW = pulseInLong(inputPin, HIGH, 10000000UL);
LowSidePW = pulseInLong(inputPin, LOW, 10000000UL);
PulseWidth = PulseWidth + HighSidePW + LowSidePW;

lcd.setCursor(0, 0);
lcd.print(" ");
lcd.setCursor(0, 0);
lcd.print(frequency * 6);

lcd.print(" RPM ");

lcd.setCursor(0, 1);
lcd.print(" ");

lcd.setCursor(0, 1);
lcd.print(frequency);
lcd.print(" Hz");
delay(500);
}

Видео Lathe DIY Tachometer and Stroboscope Part 1 канала Mad Scientist Hut