Hi all, I have a project I would like some help with. The code I have so far is attached and works great. It is on a pro mini 16Mhz clone. I repair CDI modules for mowers and other small engines and for a couple years I have had a 555 timer that I have used for testing. It is lacking in several ways. Now I have started this project that will have:
- a LCD to display rpm from 500 to 3000
- generate a pulse at intervals from 120Ms to 20Ms to trigger the CDI (one pulse / revolution)
- generate pulses at 50Hz to 300Hz to simulate the charging coils. Here may be the tricky
part, as there are 6 pulses per revolution, but skip every 6th pulse and have that time interval
align with the above triggering pulse. (you don’t want a triggering pulse at the same time the
charging coil has output because the part that the charging coil charges is shorted at that
moment) - input the trigger pulse and also input a signal from the coil and display the time interval as ° timing, as at low rpm there is a delay varying from 100us to 0us approx. The delay at low rpm is taken away at higher rpm to produce advance.
What I have so far is the LCD which works well and displays the rpm. Also for now I had it display the Ms between pulses just to be sure it was changing correctly. The pulse out I made 1Ms and used 2 transistors to switch 12 vdc to the input of the CDI, works well. I added the pin 7 output as the future high pulse rate simulating charging coils. I will feed this also with 2 transistors through a transformer to obtain approx 200 vac.
Thanks, hope it is not to ambitious!
(edited errors)
//Pulse Generator Arduino Code
#include "U8glib.h"
U8GLIB_ST7920_128X64_1X u8g(13, 11, 10); // SPI Com: SCK = en = 15, MOSI = rw = 16, CS = di = 17
int pot1 = A5; // select the input pin for the pot
int potValue = 0; // variable to store the value coming from the sensor
int pulseValue = 0; // 2 variables from one pot
int delayValue = 0;
int outputPin = 8; // select the pin for the output for trigger pulse
int chargePin = 7; // select the pin for the output for charge pulses
void draw() {
// graphic commands to redraw the complete screen should be placed here
u8g.setPrintPos(0, 15); // call procedure from base class, http://arduino.cc/en/Serial/Print
u8g.print("RPM =");
u8g.setPrintPos(50, 15);
u8g.print(potValue);
u8g.setPrintPos(8, 30);
u8g.print("Ms =");
u8g.setPrintPos(50, 30);
u8g.print(pulseValue);
u8g.setPrintPos(0, 45);
u8g.print("Advance =");
u8g.setPrintPos(80, 45);
u8g.print("10"); // for use in future code
}
void setup() {
Serial.begin(115200); // serial com speed for display
// flip screen, if required
// u8g.setRot180();
pinMode(outputPin, OUTPUT); // declare the outputPin as an OUTPUT
pinMode(chargePin, OUTPUT); // declare the chargePin as an OUTPUT
u8g.firstPage();
u8g.setFont(u8g_font_unifont);
delay (2000);
//Timer1 set up 2ms pulse every 50 ms
TCCR1A = 0;
TCCR1B = (1 << WGM12);//CTC mode to OCR1A
OCR1A = 12500; //50 ms to top value
TIMSK1 |= (1 << OCIE1A);//interrupt enable compareA
TIMSK1 |= (1 << OCIE1B);//interrupt enable compareB
OCR1B = 250; //1 ms pulse width
TCCR1B |= (1 << CS11) |(1<<CS10); //prescaler 64 4us/tick
}
void loop() {
// picture loop
u8g.firstPage();
do {
draw();
} while( u8g.nextPage() );
potValue = analogRead(pot1); // read the value from the pot for rpm
pulseValue = analogRead(pot1); // read the value from the pot for pulse
delayValue = analogRead(pot1); // read the value from the pot for pulse delay
potValue = map(potValue, 0, 1023, 500, 3000); // map pot for 500 - 3000 for rpm display
pulseValue = map(pulseValue, 0, 1023, 120, 20); // map pot for pulse delay 20 to 120 Ms
delayValue = map(delayValue, 0, 1023, 30000, 5000); // map pot for actual pulse delay
delay (10);
}
ISR(TIMER1_COMPA_vect) {
OCR1A = (delayValue); // value to set delay between pulses
digitalWrite(outputPin,HIGH); //turn on pin 8
digitalWrite(chargePin,HIGH); //turn on pin 7
}
ISR(TIMER1_COMPB_vect) {
digitalWrite(outputPin,LOW); //turn off pin 8
digitalWrite(chargePin,LOW); //turn off pin 7
}
