Affordable electrode polishing machine

The Arduino sketch is the program that runs in the Arduino microcontroller, in our case, the Nano. The sketch is very simple and can be uploaded to the board using the Arduino IDE. The sketch is bellow and can be copy and past to the the Arduino IDE. There is plenty of information on how to upload sketches to Arduino boards online, this is the easy part. What the sketch does is to read the potentiometer position, scale that to a value the correspond to the max and min speed of the ESC, signalling the value to the ESC. It also scales the potentiometer position, and hence the ESC speed, to the number of LEDs in the bar, which are 10, making it a visual display of the EWC and HDD motor speed. 

One other thing the sketch has is the ability to program the ESC. Sometimes ESCs need to be programmed to know what are the signals to max and min speed. This is not required all the time, but it is useful to do at least once in the ESC life. There was a version of the sketch that programmed the ESC automatically every power up, but some ESC have different timings on the program routine so this is not very convenient or feasible. To program an ESC it need to be powered with the 12 V while sending a signal of max speed. Once the ESC beeps at you, you need to send the signal for the min speed. It will beep once again and the programming is done. To avoid acidental programming, i.e. powering up the Funiitriz wile the potentiometer is at “full beans”, the code incorporates a line that sets the ESC speed to zero at every power up for a few seconds. This is the line “esc.write(0);” in the setup loop. 

To calibrate the ESC, disconnect the 12 V power (power supply from the barrel jack), comment the the lines in the setup loop as commented in the sketch. Connect the arduino to a computer and upload the sketch. Once done, disconnect the Arduino from the computer and reconnect the 12 V power supply to it, without turning the Funiitriz on on the power switch yet. Turn the potentiometer to full speed and now turn on the power switch. Once the ESC beeps at you, turn the potentiometer all the way down. The ESC will beep again. Once that is done, turn the power off. Uncomment the lines that where commented before in the sketch and upload it to the Arduino. Once that is done the Funnitriz is ready to be used with a programmed ESC. When you power it one, all the LEDs will blink 3 times, the ESC might beep some, but after the LEDs blink, it is ready to use!

#include <Servo.h>

Servo esc; // create servo object to control the ESC for the brushless motor

const int ledCount = 10; // the number of LEDs in the bar graph

int ledPins[] = {3,4,5,6,7,8,9,10,11,12}; // an array of pin numbers to which LEDs are attached

int potpin = A0; // analog pin used to connect the potentiometer

int val = 0; // variable to read the value from the analog pin

int ledLevel = 0;

void setup()

{

Serial.begin(9600);

esc.attach(13,1000,2000); // attaches the ESC

for (int thisLed = 0; thisLed <= ledCount; thisLed++) {

pinMode(ledPins[thisLed], OUTPUT);

}

//FOR CALIBRATING THE ESC COMMENT EVERYTHING BEYOND HERE UNTIL THE END OF THE SETUP LOOP (void setup)

esc.write(0);

delay(200);

for (int thisLed = 0; thisLed <= ledCount; thisLed++) {

digitalWrite(ledPins[thisLed], HIGH);

}

delay(200);

for (int thisLed = 0; thisLed <= ledCount; thisLed++) {

digitalWrite(ledPins[thisLed], LOW);

}

delay(200);

for (int thisLed = 0; thisLed <= ledCount; thisLed++) {

digitalWrite(ledPins[thisLed], HIGH);

}

delay(200);

for (int thisLed = 0; thisLed <= ledCount; thisLed++) {

digitalWrite(ledPins[thisLed], LOW);

}

delay(200);

for (int thisLed = 0; thisLed <= ledCount; thisLed++) {

digitalWrite(ledPins[thisLed], HIGH);

}

delay(200);

for (int thisLed = 0; thisLed <= ledCount; thisLed++) {

digitalWrite(ledPins[thisLed], LOW);

}

}

void loop()

{

val = analogRead(potpin); // reads the value of the potentiometer (value between 0 and 1023)

delay(10);

val = map(val, 1023, 0, 30, 170); // scale it to use it with the servo (value between 0 and 180)

esc.write(val); // sets the servo position according to the scaled value

ledLevel = map(val, 30, 160, 0, 10);

Serial.println(val); // FOR DEBUGGING

for (int thisLed = 0; thisLed <= ledCount; thisLed++) {

if (thisLed < ledLevel) {

digitalWrite(ledPins[thisLed], HIGH);

}

else {

digitalWrite(ledPins[thisLed], LOW);

}

}

delay(100);

}