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| ///////////////
// Calibration:
///////////////
const byte PulsesPerRevolution = 4; // Set how many pulses there are on each revolution. Default: 2.
// If the period between pulses is too high, or even if the pulses stopped, then we would get stuck showing the
// last value instead of a 0. Because of this we are going to set a limit for the maximum period allowed.
// If the period is above this value, the RPM will show as 0.
// The higher the set value, the longer lag/delay will have to sense that pulses stopped, but it will allow readings
// at very low RPM.
// Setting a low value is going to allow the detection of stop situations faster, but it will prevent having low RPM readings.
// The unit is in microseconds.
const unsigned long ZeroTimeout = 100000; // For high response time, a good value would be 100000.
// For reading very low RPM, a good value would be 300000.
// Calibration for smoothing RPM:
const byte numReadings = 2; // Number of samples for smoothing. The higher, the more smoothing, but it's going to
// react slower to changes. 1 = no smoothing. Default: 2.
/////////////
// Variables:
/////////////
volatile unsigned long LastTimeWeMeasured; // Stores the last time we measured a pulse so we can calculate the period.
volatile unsigned long PeriodBetweenPulses = ZeroTimeout+1000; // Stores the period between pulses in microseconds.
// It has a big number so it doesn't start with 0 which would be interpreted as a high frequency.
volatile unsigned long PeriodAverage = ZeroTimeout+1000; // Stores the period between pulses in microseconds in total, if we are taking multiple pulses.
// It has a big number so it doesn't start with 0 which would be interpreted as a high frequency.
unsigned long FrequencyRaw; // Calculated frequency, based on the period. This has a lot of extra decimals without the decimal point.
unsigned long FrequencyReal; // Frequency without decimals.
unsigned long RPM; // Raw RPM without any processing.
unsigned int PulseCounter = 1; // Counts the amount of pulse readings we took so we can average multiple pulses before calculating the period.
unsigned long PeriodSum; // Stores the summation of all the periods to do the average.
unsigned long LastTimeCycleMeasure = LastTimeWeMeasured; // Stores the last time we measure a pulse in that cycle.
// We need a variable with a value that is not going to be affected by the interrupt
// because we are going to do math and functions that are going to mess up if the values
// changes in the middle of the cycle.
unsigned long CurrentMicros = micros(); // Stores the micros in that cycle.
// We need a variable with a value that is not going to be affected by the interrupt
// because we are going to do math and functions that are going to mess up if the values
// changes in the middle of the cycle.
// We get the RPM by measuring the time between 2 or more pulses so the following will set how many pulses to
// take before calculating the RPM. 1 would be the minimum giving a result every pulse, which would feel very responsive
// even at very low speeds but also is going to be less accurate at higher speeds.
// With a value around 10 you will get a very accurate result at high speeds, but readings at lower speeds are going to be
// farther from eachother making it less "real time" at those speeds.
// There's a function that will set the value depending on the speed so this is done automatically.
unsigned int AmountOfReadings = 1;
unsigned int ZeroDebouncingExtra; // Stores the extra value added to the ZeroTimeout to debounce it.
// The ZeroTimeout needs debouncing so when the value is close to the threshold it
// doesn't jump from 0 to the value. This extra value changes the threshold a little
// when we show a 0.
// Variables for smoothing tachometer:
unsigned long readings[numReadings]; // The input.
unsigned long readIndex; // The index of the current reading.
unsigned long total; // The running total.
unsigned long average; // The RPM value after applying the smoothing.
#include <TinyGPS++.h>
#include <SoftwareSerial.h>
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
float current;
int termPin = 6; //termistor pin connection
int termNom = 100000; //resistancve du termistor
int refTemp = 25; //
int beta = 3950;
int resistance = 100000; // valeure resistance serie
// OLED 0.96" Display:
#include <Adafruit_GFX.h> // Include core graphics library for the display.
#include <Adafruit_SSD1306.h> // Include Adafruit_SSD1306 library to drive the display.
Adafruit_SSD1306 display(128, 64); // Create display.
#include <Fonts/FreeMonoBold18pt7b.h> // Add a custom font.
const int RXPin = 2, TXPin = 5;
const uint32_t GPSBaud = 9600; //Default baud of NEO-6M is 9600
TinyGPSPlus gps; // the TinyGPS++ object
SoftwareSerial gpsSerial(RXPin, TXPin); // the serial interface to the GPS device
//variable
void setup() { // Start of setup:
{{
Serial.begin(9600); // Begin serial communication.
{gpsSerial.begin(GPSBaud);
{attachInterrupt(digitalPinToInterrupt(3), Pulse_Event, RISING); // Enable interruption pin 2 when going from LOW to HIGH. { Serial.begin(9600);
}
delay(1000); // We sometimes take several readings of the period to average. Since we don't have any readings
// stored we need a high enough value in micros() so if divided is not going to give negative values.
// The delay allows the micros() to be high enough for the first few cycles.
// OLED 0.96" Display:
display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // Initialize display with the I2C address of 0x3C.
display.clearDisplay(); // Clear the buffer.
display.setTextColor(WHITE); // Set color of the text to white.
display.setRotation(0); // Set orientation. Goes from 0, 1, 2 or 3.
display.setTextWrap(false); // By default, long lines of text are set to automatically “wrap” back to the leftmost column.
// To override this behavior (so text will run off the right side of the display - useful for
// scrolling marquee effects), use setTextWrap(false). The normal wrapping behavior is restored
// with setTextWrap(true).
display.dim(0); // Set brightness (0 is maximum and 1 is a little dim).
// End of setup.
void Pulse_Event() // The interrupt runs this to calculate the period between pulses:
{
PeriodBetweenPulses = micros() - LastTimeWeMeasured; // Current "micros" minus the old "micros" when the last pulse happens.
// This will result with the period (microseconds) between both pulses.
// The way is made, the overflow of the "micros" is not going to cause any issue.
LastTimeWeMeasured = micros(); // Stores the current micros so the next time we have a pulse we would have something to compare with.
if(PulseCounter >= AmountOfReadings) // If counter for amount of readings reach the set limit:
{
PeriodAverage = PeriodSum / AmountOfReadings; // Calculate the final period dividing the sum of all readings by the
// amount of readings to get the average.
PulseCounter = 1; // Reset the counter to start over. The reset value is 1 because its the minimum setting allowed (1 reading).
PeriodSum = PeriodBetweenPulses; // Reset PeriodSum to start a new averaging operation.
// Change the amount of readings depending on the period between pulses.
// To be very responsive, ideally we should read every pulse. The problem is that at higher speeds the period gets
// too low decreasing the accuracy. To get more accurate readings at higher speeds we should get multiple pulses and
// average the period, but if we do that at lower speeds then we would have readings too far apart (laggy or sluggish).
// To have both advantages at different speeds, we will change the amount of readings depending on the period between pulses.
// Remap period to the amount of readings:
int RemapedAmountOfReadings = map(PeriodBetweenPulses, 40000, 5000, 1, 10); // Remap the period range to the reading range.
// 1st value is what are we going to remap. In this case is the PeriodBetweenPulses.
// 2nd value is the period value when we are going to have only 1 reading. The higher it is, the lower RPM has to be to reach 1 reading.
// 3rd value is the period value when we are going to have 10 readings. The higher it is, the lower RPM has to be to reach 10 readings.
// 4th and 5th values are the amount of readings range.
RemapedAmountOfReadings = constrain(RemapedAmountOfReadings, 1, 10); // Constrain the value so it doesn't go below or above the limits.
AmountOfReadings = RemapedAmountOfReadings; // Set amount of readings as the remaped value.
}
else
{
PulseCounter++; // Increase the counter for amount of readings by 1.
PeriodSum = PeriodSum + PeriodBetweenPulses; // Add the periods so later we can average.
// End of Pulse_Event.
}
void loop() {
if (gpsSerial.available() > 0) {
if (gps.encode(gpsSerial.read())) {
//display.clearDisplay () ;
// display.setCursor (0,0) ;
// display.print(F("- speed: "));
if (gps.speed.isValid()) {
.clearDisplay () ;
display.setTextSize (4) ;
display.setCursor (0,5) ;
display.print(gps.speed.kmph());
display.display () ;
delay (3000) ;
//if (gps.date.isValid() && gps.time.isValid()) {
display.clearDisplay () ;
display.setTextSize (4) ;
// display.setTextColor (WHITE) ;
display.setCursor (0,5) ;
//display.clearDisplay () ;
display.print(gps.time.hour() +1 +1);
display.print(F(":"));
display.print(gps.time.minute());
// display.print(F(":"));
// display.println(gps.time.second());
display.display () ;
delay (1000) ;
current = analogRead(termPin);
current = 1023 / current - 1;
current = resistance / current;
float temperature;
temperature = current / termNom;
temperature = log(temperature);
temperature /= beta;
temperature += 1.0 / (refTemp + 273.15);
temperature = 1.0 / temperature;
temperature -= 273.15;
display.clearDisplay () ;
display.setTextSize (4) ;
display.setCursor ( 0,5) ;
display.print(temperature,1);
display.display () ;
delay (2000);
}}
// The following is going to store the two values that might change in the middle of the cycle.
// We are going to do math and functions with those values and they can create glitches if they change in the
// middle of the cycle.
LastTimeCycleMeasure = LastTimeWeMeasured; // Store the LastTimeWeMeasured in a variable.
CurrentMicros = micros(); // Store the micros() in a variable.
// CurrentMicros should always be higher than LastTimeWeMeasured, but in rare occasions that's not true.
// I'm not sure why this happens, but my solution is to compare both and if CurrentMicros is lower than
// LastTimeCycleMeasure I set it as the CurrentMicros.
// The need of fixing this is that we later use this information to see if pulses stopped.
if(CurrentMicros < LastTimeCycleMeasure)
{
LastTimeCycleMeasure = CurrentMicros;
}
// Calculate the frequency:
FrequencyRaw = 10000000000 / PeriodAverage; // Calculate the frequency using the period between pulses.
// Detect if pulses stopped or frequency is too low, so we can show 0 Frequency:
if(PeriodBetweenPulses > ZeroTimeout - ZeroDebouncingExtra || CurrentMicros - LastTimeCycleMeasure > ZeroTimeout - ZeroDebouncingExtra)
{ // If the pulses are too far apart that we reached the timeout for zero:
FrequencyRaw = 0; // Set frequency as 0.
ZeroDebouncingExtra = 2000; // Change the threshold a little so it doesn't bounce.
}
else
{
ZeroDebouncingExtra = 0; // Reset the threshold to the normal value so it doesn't bounce.
}
FrequencyReal = FrequencyRaw / 10000; // Get frequency without decimals.
// This is not used to calculate RPM but we remove the decimals just in case
// you want to print it.
// Calculate the RPM:
RPM = FrequencyRaw / PulsesPerRevolution * 60; // Frequency divided by amount of pulses per revolution multiply by
// 60 seconds to get minutes.
RPM = RPM / 10000; // Remove the decimals.
// Smoothing RPM:
total = total - readings[readIndex]; // Advance to the next position in the array.
readings[readIndex] = RPM; // Takes the value that we are going to smooth.
total = total + readings[readIndex]; // Add the reading to the total.
readIndex = readIndex + 1; // Advance to the next position in the array.
if (readIndex >= numReadings) // If we're at the end of the array:
{
readIndex = 0; // Reset array index.
}
// Calculate the average:
average = total / numReadings; // The average value it's the smoothed result.
/*
// Print information on the serial monitor:
// Comment this section if you have a display and you don't need to monitor the values on the serial monitor.
// This is because disabling this section would make the loop run faster.
Serial.print("Period: ");
Serial.print(PeriodBetweenPulses);
Serial.print("\tReadings: ");
Serial.print(AmountOfReadings);
Serial.print("\tFrequency: ");
Serial.print(FrequencyReal);
Serial.print("\tRPM: ");
Serial.print(RPM);
Serial.print("\tTachometer: ");
Serial.println(average);
*/
// OLED 0.96" Display:
// Convert variable into a string, so we can change the text alignment to the right:
// It can be also used to add or remove decimal numbers.
char string[10]; // Create a character array of 10 characters
// Convert float to a string:
dtostrf(average, 6, 0, string); // (<variable>,<amount of digits we are going to use>,<amount of decimal digits>,<string name>)
display.clearDisplay(); // Clear the display so we can refresh.
display.setFont(&FreeMonoBold18pt7b); // Set a custom font.
display.setTextSize(0); // Set text size. We are using a custom font so you should always use the text size of 0.
display.setCursor(0, 25); // (x,y).
display.println("RPM:"); // Text or value to print.
// Print variable with right alignment:
display.setCursor(0, 60); // (x,y).
display.println(string); // Text or value to print.
// Print a comma for the thousands separator:
if(average > 999) // If value is above 999:
{
// Draw line (to show a comma):
display.drawLine(63, 60, 61, 65, WHITE); // Draw line (x0,y0,x1,y1,color).
}
display.display(); // Print everything we set previously.
// delay (3000) ;
//} // End of loop.
// End of Pulse_Event.
}
void Pulse_Event() // The interrupt runs this to calculate the period between pulses:
{
PeriodBetweenPulses = micros() - LastTimeWeMeasured; // Current "micros" minus the old "micros" when the last pulse happens.
// This will result with the period (microseconds) between both pulses.
// The way is made, the overflow of the "micros" is not going to cause any issue.
LastTimeWeMeasured = micros(); // Stores the current micros so the next time we have a pulse we would have something to compare with.
if(PulseCounter >= AmountOfReadings) // If counter for amount of readings reach the set limit:
{
PeriodAverage = PeriodSum / AmountOfReadings; // Calculate the final period dividing the sum of all readings by the
// amount of readings to get the average.
PulseCounter = 1; // Reset the counter to start over. The reset value is 1 because its the minimum setting allowed (1 reading).
PeriodSum = PeriodBetweenPulses; // Reset PeriodSum to start a new averaging operation.
// Change the amount of readings depending on the period between pulses.
// To be very responsive, ideally we should read every pulse. The problem is that at higher speeds the period gets
// too low decreasing the accuracy. To get more accurate readings at higher speeds we should get multiple pulses and
// average the period, but if we do that at lower speeds then we would have readings too far apart (laggy or sluggish).
// To have both advantages at different speeds, we will change the amount of readings depending on the period between pulses.
// Remap period to the amount of readings:
int RemapedAmountOfReadings = map(PeriodBetweenPulses, 40000, 5000, 1, 10); // Remap the period range to the reading range.
// 1st value is what are we going to remap. In this case is the PeriodBetweenPulses.
// 2nd value is the period value when we are going to have only 1 reading. The higher it is, the lower RPM has to be to reach 1 reading.
// 3rd value is the period value when we are going to have 10 readings. The higher it is, the lower RPM has to be to reach 10 readings.
// 4th and 5th values are the amount of readings range.
RemapedAmountOfReadings = constrain(RemapedAmountOfReadings, 1, 10); // Constrain the value so it doesn't go below or above the limits.
AmountOfReadings = RemapedAmountOfReadings; // Set amount of readings as the remaped value.
}
else
{
PulseCounter++; // Increase the counter for amount of readings by 1.
PeriodSum = PeriodSum + PeriodBetweenPulses; // Add the periods so later we can average.
// End of Pulse_Event.
}}} |
