I have an LTC2365/1 Msps 12bit-ADC with SPI pins. Somehow I only could achieve a maximum of 200 Ksps with this ADC rather than something close to 1 Msps using an Arduino Due. I wonder if anyone could help me with this issue. I tried many ways but couldn't figure it out.
Datasheet for the ADC:
http://cds.linear.com/docs/en/datasheet/23656fb.pdf
Here is the code I use for Arduino:
#include <SPI.h>
const int spi_ss = 10; // set SPI SS Pin
uint8_t byte_0, byte_1; // First and second bytes read
uint16_t spi_bytes; // final 12 bit shited value
long int starttime,endtime;
long int count=0;
void setup() {
SerialUSB.begin(2000000); // begin serial and set speed
pinMode(spi_ss, OUTPUT); // Set SPI slave select pin as output
digitalWriteDirect(spi_ss, HIGH); // Make sure spi_ss is held high
SPI.begin();
SPI.beginTransaction(SPISettings(16000000, MSBFIRST, SPI_MODE0));
loop2();
SPI.endTransaction();
}
void loop2() {
starttime=millis();
endtime=starttime;
while((endtime-starttime)<=1000) {
// write the LTC CS pin low to initiate ADC sample and data transmit
digitalWriteDirect(spi_ss, LOW);
byte_0 = spi_read(0x00); // read firt 8 bits
byte_1 = spi_read(0x00); // read second 8 bits
digitalWriteDirect(spi_ss, HIGH);
// wite LTC CS pin high to stop LTC from transmitting zeros.
spi_bytes = ( ( (byte_0 <<6) ) + (byte_1 >>2) );
SerialUSB.println(spi_bytes);
count=count+1;
endtime=millis();
}
//samples per second
SerialUSB.println(count);
}
static inline uint8_t spi_read(uint8_t b) {
return SPI.transfer(b);
}
inline void digitalWriteDirect(int pin, boolean val) {
if(val) g_APinDescription[pin].pPort -> PIO_SODR = g_APinDescription[pin].ulPin;
else g_APinDescription[pin].pPort -> PIO_CODR = g_APinDescription[pin].ulPin;
}
Related
I have connected coin hopper and coin acceptor to one arduino uno, coin acceptor connected to pin 2, coin hopper to pin 3 - sensor and pin 7 - relay. When coin hopper switch relay, it is executing coininterrupt
for coin hopper I am using this script link
coin acceptor script: link
I need this 2 scripts working on 1 arduino
my code:
#define SENSOR 3
#define RELAY 7
#define ACCEPTOR 2
volatile boolean insert = false;
int pulse=0,count;
char sen;
int temp=0;
unsigned long int timer;
void setup()
{
Serial.begin(9600);
pinMode(SENSOR,INPUT_PULLUP);
pinMode(RELAY,OUTPUT);
sen=digitalRead(SENSOR);
digitalWrite(RELAY, HIGH);
attachInterrupt(digitalPinToInterrupt(ACCEPTOR), coinInterrupt, RISING);
}
void loop()
{
if (insert) {
insert = false;
Serial.println("coin");
delay(1000);
}
if(Serial.available())
{
timer=millis();
// temp is amount to dispense send to arduino
temp=Serial.parseInt();
if(temp>0){
digitalWrite(RELAY,LOW);}
}
sen=(sen<<1)|digitalRead(SENSOR);
// if hopper sensor read drop coin
if(sen==1)
{
timer=millis();
pulse++;
sen&=0x03;
Serial.println("out 1");
//if dispensed coins equal with coins to dispense stop engine
if(pulse==temp)
{
digitalWrite(RELAY,HIGH);
pulse=0;
temp=0;
}
}
// if amount dispensed is not equal with amount to dispense and engine running, stop
if((digitalRead(RELAY)==LOW)&(millis()-timer>2000))
{
digitalWrite(RELAY,HIGH);
pulse=0;
temp=0;
}
}
void coinInterrupt() {
insert = true;
}
I was trying to change pins (arduino uno support interrupts on pin 2 and 3 only) but problem still appears so I guess there is issue in the code
your sketch does not run in this state :
first fix errors :
declare insert as volatile
remove cpulse (not used anywhere)
change 'if()' to (I suppose) 'if (insert) ....'
remove stuff with 'sen' var : simply use if(digitalRead(SENSOR)) or if(!digitalRead(SENSOR))
except if you need to store relay state.
use logical operators like || or && unless you really need bitwise operations
example of result sketch :
#define SENSOR 3
#define RELAY 7
volatile boolean insert = false;
byte amountToDispense = 0;
int pulse = 0;
int temp = 0;
unsigned long int timer;
void setup()
{
Serial.begin(9600);
pinMode(SENSOR, INPUT_PULLUP);
pinMode(RELAY, OUTPUT);
digitalWrite(RELAY, HIGH);
attachInterrupt(digitalPinToInterrupt(2), coinInterrupt, RISING);
}
void loop()
{
if (insert ) {
insert = false;
Serial.println("coin");
delay(1000);
}
if (Serial.available())
{
timer = millis();
temp = Serial.parseInt();
if (temp > 0) {
//amountToDispense = Serial.read() - 48;
digitalWrite(RELAY, LOW);
}
}
if (digitalRead(SENSOR))
{
timer = millis();
pulse++;
Serial.println("out 1");
if (pulse >= temp)
{
digitalWrite(RELAY, HIGH);
pulse = 0;
temp = 0;
}
}
if (!digitalRead(RELAY) && (millis() - timer > 2000))
{
digitalWrite(RELAY, HIGH);
pulse = 0;
temp = 0;
}
}
void coinInterrupt() {
insert = true;
}
What is this supposed to do?
sen=(sen<<1)|digitalRead(SENSOR);
You init sen with digitalRead(SENSOR);
Assuming that pin is LOW when you start the sketch and turns HIGH, sen will become 1.
Next you do sen &= 0x03 so sen is still 1.
Again sen=(sen<<1)|digitalRead(SENSOR); , sen will either be 2 or 3.
Next loop run sen=(sen<<1)|digitalRead(SENSOR); sen is now 4 or 6. and so on...
I don't have time to think about what you want to achieve but this is definitely a problem as you'll only enter if (sen == 1) once and never again.
If this is not sufficient you should probably improve your post as it is unclear what arduino sends bad signal to interrup pin is supposed to mean. That doesn't make sense. Explain the expected behaviour of your program and how it behaves instead. add more comments so it becomes clear what you intend to do with each block of code so we don't have to interpret
i want to record a long data for like 2 to 3 hours using microcontroller Arduino Mega 2560 WI-FI R3 but I got this warning in my code
below is the picture of the warning i got.
enter image description here
the warning come up when I put the time out constant more than 30000 milliseconds
below is the code I used for the Arduino
#include "DHT.h"
// Pin Definitions
#define DHT_PIN_OUT A1
#define DHTTYPE DHT11
#define MQ3_PIN_OUT A2
#define MQ4_PIN_OUT A3
#define MQ7_PIN_OUT A4
// Global variables and defines
// object initialization
DHT dht(DHT_PIN_OUT, DHTTYPE);
// define vars for testing menu
const int timeout = 180000; //define timeout of 1 hour
char menuOption = 0;
long time0;
// Setup the essentials for your circuit to work. It runs first every time your circuit is powered with electricity.
void setup()
{
// Setup Serial which is useful for debugging
// Use the Serial Monitor to view printed messages
Serial.begin(9600);
while (!Serial) ; // wait for serial port to connect. Needed for native USB
Serial.println("start");
dht.begin();
menuOption = menu();
}
// Main logic of your circuit. It defines the interaction between the components you selected. After setup, it runs over and over again, in an eternal loop.
void loop(){
if(menuOption == '1') {
delay(500); //delay 0.5 second
// DHT11 Humidity and Temperature Sensor
// Reading humidity in %
float dhtHumidity = dht.readHumidity();
// Read temperature in Celsius, for Fahrenheit use .readTempF()
float dhtTempC = dht.readTemperature();
float Alcohol = analogRead(MQ3_PIN_OUT);
float Methane = analogRead(MQ4_PIN_OUT);
float CarbonMonoxide = analogRead(MQ7_PIN_OUT);
Serial.print(F("Humidity: ")); Serial.print(dhtHumidity); Serial.print(F("[%]\t"));
Serial.print(F("Temp: ")); Serial.print(dhtTempC); Serial.print(F("[C]\t"));
Serial.print(F("Alcohol: ")); Serial.print(Alcohol); Serial.print(F(" \t"));
Serial.print(F("Methane: ")); Serial.print(Methane); Serial.print(F(" \t"));
Serial.print(F("Carbon Monoxide: ")); Serial.println(CarbonMonoxide); Serial.println(F(" \t"));
}
if (millis() - time0 > timeout){
menuOption = menu();
}
}
// Menu function for selecting the components to be tested
// Follow serial monitor for instrcutions
char menu(){
Serial.println(F("\nSensor Array"));
Serial.println(F("Press (1) to start the sensor array"));
while (!Serial.available());
// Read data from serial monitor if received
while (Serial.available()){
char c = Serial.read();
if (isAlphaNumeric(c))
{
if(c == '1')
Serial.println(F("Now running the sensor array"));
else{
Serial.println(F("illegal input!"));
menuOption = menu();
return 0;
}
time0 = millis();
return c;
}
}
}
sorry for my bad programming and silly question, I'm new to this kind of thing. and I just found out that people usually get answers from StackOverflow, so I just wanted to try asking because I have tried to google the answer but I can't find it.
I'm trying to control the speed of two DC motors using an Arduino Uno and encoders that are connected to the motors.
I've written a code to check whether there's a change in the position of the encoder and according to that calculate the velocity of the motors.
Ive used this website for the code:
I'm having problems when calculating the difference between the new position of the encoder and the old position of the encoder. For some reason that difference keeps going up even though the speed stays the same.
This is my code so far:
#define pwmLeft 10
#define pwmRight 5
#define in1 9
#define in2 8
#define in3 7
#define in4 6
//MOTOR A
int motorSpeedA = 100;
static int pinA = 2; // Our first hardware interrupt pin is digital pin 2
static int pinB = 3; // Our second hardware interrupt pin is digital pin 3
volatile byte aFlag = 0; // let's us know when we're expecting a rising edge on pinA to signal that the encoder has arrived at a detent
volatile byte bFlag = 0; // let's us know when we're expecting a rising edge on pinB to signal that the encoder has arrived at a detent (opposite direction to when aFlag is set)
volatile long encoderPos = 0; //this variable stores our current value of encoder position. Change to int or uin16_t instead of byte if you want to record a larger range than 0-255
volatile long oldEncPos = 0; //stores the last encoder position value so we can compare to the current reading and see if it has changed (so we know when to print to the serial monitor)
volatile long reading = 0; //somewhere to store the direct values we read from our interrupt pins before checking to see if we have moved a whole detent
//MOTOR B
static int pinC = 12; // Our first hardware interrupt pin is digital pin 2
static int pinD = 33; // Our second hardware interrupt pin is digital pin 3
volatile byte cFlag = 0; // let's us know when we're expecting a rising edge on pinA to signal that the encoder has arrived at a detent
volatile byte dFlag = 0; // let's us know when we're expecting a rising edge on pinB to signal that the encoder has arrived at a detent (opposite direction to when aFlag is set)
volatile long encoderPosB = 0; //this variable stores our current value of encoder position. Change to int or uin16_t instead of byte if you want to record a larger range than 0-255
volatile long oldEncPosB = 0; //stores the last encoder position value so we can compare to the current reading and see if it has changed (so we know when to print to the serial monitor)
volatile long readingB = 0;
int tempPos;
long vel;
unsigned long newtime;
unsigned long oldtime = 0;
void setup() {
//MOTOR A
pinMode(pinA, INPUT_PULLUP); // set pinA as an input, pulled HIGH to the logic voltage (5V or 3.3V for most cases)
pinMode(pinB, INPUT_PULLUP); // set pinB as an input, pulled HIGH to the logic voltage (5V or 3.3V for most cases)
attachInterrupt(0, PinA, RISING); // set an interrupt on PinA, looking for a rising edge signal and executing the "PinA" Interrupt Service Routine (below)
attachInterrupt(1, PinB, RISING); // set an interrupt on PinB, looking for a rising edge signal and executing the "PinB" Interrupt Service Routine (below)
//MOTOR B
pinMode(pinC, INPUT_PULLUP); // set pinA as an input, pulled HIGH to the logic voltage (5V or 3.3V for most cases)
pinMode(pinD, INPUT_PULLUP); // set pinB as an input, pulled HIGH to the logic voltage (5V or 3.3V for most cases)
attachInterrupt(0, PinC, RISING); // set an interrupt on PinA, looking for a rising edge signal and executing the "PinA" Interrupt Service Routine (below)
attachInterrupt(1, PinD, RISING);
Serial.begin(9600); // start the serial monitor link
pinMode (in1, OUTPUT);
pinMode (in2, OUTPUT);
pinMode (in3, OUTPUT);
pinMode (in4, OUTPUT);
digitalWrite (8, HIGH);
digitalWrite (9, LOW); //LOW
digitalWrite (7, LOW); //LOW
digitalWrite (6, HIGH);
pinMode (pwmLeft, OUTPUT);
pinMode (pwmRight, OUTPUT);
}
void PinA(){
cli(); //stop interrupts happening before we read pin values
reading = PIND & 0xC; // read all eight pin values then strip away all but pinA and pinB's values
if(reading == B00001100 && aFlag) { //check that we have both pins at detent (HIGH) and that we are expecting detent on this pin's rising edge
encoderPos --; //decrement the encoder's position count
bFlag = 0; //reset flags for the next turn
aFlag = 0; //reset flags for the next turn
} else if (reading == B00000100) bFlag = 1; //signal that we're expecting pinB to signal the transition to detent from free rotation
sei(); //restart interrupts
}
void PinB(){
cli(); //stop interrupts happening before we read pin values
reading = PIND & 0xC; //read all eight pin values then strip away all but pinA and pinB's values
if (reading == B00001100 && bFlag) { //check that we have both pins at detent (HIGH) and that we are expecting detent on this pin's rising edge
encoderPos ++; //increment the encoder's position count
bFlag = 0; //reset flags for the next turn
aFlag = 0; //reset flags for the next turn
} else if (reading == B00001000) aFlag = 1; //signal that we're expecting pinA to signal the transition to detent from free rotation
sei(); //restart interrupts
}
void PinC(){
cli(); //stop interrupts happening before we read pin values
readingB = PIND & 0xC; // read all eight pin values then strip away all but pinA and pinB's values
if(readingB == B00001100 && cFlag) { //check that we have both pins at detent (HIGH) and that we are expecting detent on this pin's rising edge
encoderPosB --; //decrement the encoder's position count
dFlag = 0; //reset flags for the next turn
cFlag = 0; //reset flags for the next turn
} else if (readingB == B00000100) dFlag = 1; //signal that we're expecting pinB to signal the transition to detent from free rotation
sei(); //restart interrupts
}
void PinD(){
cli(); //stop interrupts happening before we read pin values
readingB = PIND & 0xC; //read all eight pin values then strip away all but pinA and pinB's values
if (readingB == B00001100 && dFlag) { //check that we have both pins at detent (HIGH) and that we are expecting detent on this pin's rising edge
encoderPosB ++; //increment the encoder's position count
dFlag = 0; //reset flags for the next turn
cFlag = 0; //reset flags for the next turn
} else if (readingB == B00001000) cFlag = 1; //signal that we're expecting pinA to signal the transition to detent from free rotation
sei(); //restart interrupts
}
void loop(){
analogWrite(pwmLeft, motorSpeedA);
analogWrite(pwmRight, motorSpeedA);
if(oldEncPos != encoderPos) {
newtime = millis();
tempPos = encoderPos - oldEncPos;
vel = tempPos / (newtime - oldtime);
Serial.println(tempPos);
oldEncPos = encoderPos;
oldtime = newtime;
delay(250);
}
if(oldEncPosB != encoderPosB) {
Serial.println(encoderPosB);
oldEncPosB = encoderPosB;
}
}
The two if statements are just made to check that the encoders are working properly. In the first if statement I'm trying to do the calculations of the velocity.
I would appreciate any feedback.
Thank you.
EDIT:
I found out theres an encoder library which makes everything a lot easier.
so now my code looks like this:
#include <Encoder.h>
#define pwmLeft 10
#define pwmRight 5
Encoder myEncA(3, 2);
Encoder myEncB(13, 12);
unsigned long oldtimeA = 0;
unsigned long oldtimeB = 0;
int speedA = 100;
int speedB = 130;
void setup() {
Serial.begin(9600);
digitalWrite (8, HIGH);
digitalWrite (9, LOW); //LOW
digitalWrite (7, LOW); //LOW
digitalWrite (6, HIGH);
pinMode (pwmLeft, OUTPUT);
pinMode (pwmRight, OUTPUT);
}
long oldPositionA = -999;
long oldPositionB = -999;
void loop() {
analogWrite(pwmLeft, speedA);
analogWrite(pwmRight, speedB);
long newPositionA = myEncA.read();
long newPositionB = myEncB.read();
if ((newPositionA != oldPositionA) || (newPositionB != oldPositionB)) {
unsigned long newtimeA = millis ();
long positionA = newPositionA - oldPositionA;
long positionB = newPositionB - oldPositionB;
long velB = (positionB) / (newtimeA - oldtimeA);
long velA = (positionA) / (newtimeA - oldtimeA);
oldtimeA = newtimeA;
oldPositionA = newPositionA;
oldPositionB = newPositionB;
Serial.println(velB);
}
}
I am still having problems with my "B" motor, the calculation is still way off for some reason.
Motor "A" works fine
A couple of issues, including a divide by zero error in loop(). This scan cause a reset of your controller. Always check the value of the divisor when doing a division!
Using only positive transitions unnecessarily reduces the resolution of your readings by 2.
The Arduino is an 8bit controller... Reading an int requires multiple instruction, which means you should disable interrupts before reading an int that's modified by an interrupt routine. Failure to do so will cause odd jumps in the vakue read. This is usually done like this:
//...
NoInterrupts();
int copyOfValue = value; // use the copy to work with.
interrupts();
//...
In your case, a single byte value is likely enough to store movement, with a reset every 30 ms, this should give you a top speed of 255 pulses/30ms = 8500 pulses/second or 1275000 rpm for a 24 ticks/turn encoder. :) in that case, no need to disable interrupts for a reading.
with one reading per 30ms, 1 tick /30ms = 33 tick/seconds, or 85 RPM. It's a bit high for motion. You may need to average readings, depending on your application.
Also, the algorithm you are using will definitely not work. The main reason is that the delay between reads and adjustments is too small. Most readings will be of zero. You will run into the problem when removing the println() calls. I suggest a pacing of at least 30 ms between readings. 100 ms may work a bit better, depending on your application. Using a float variable for speed average will definitely help.
void loop()
{
//...
if(oldEncPos != encoderPos) {
newtime = millis();
tempPos = encoderPos - oldEncPos;
vel = tempPos / (newtime - oldtime); // <-- if newtime == oltime => divide by zero.
//...
}
//...
}
The encoder reading code seems awfully complex...
#define PIN_A 2 // encoder bit 0
#define PIN_B 3 // encoder bit 1
volatile char encVal1;
volatile unsigned char encPos1; // using char
void OnEncoder1Change()
{
char c = (digitalRead(pinA) ? 0b01 : 0)
+ (digitalRead(pinB) ? 0b10 : 0); // read
char delta = (c - encVal1) & 0b11; // get difference, mask
if (delta == 1) // delta is either 1 or 3
++encPos1;
else
--encPos1;
encVal1 = c; // keep reading for next time.
encPos1 += delta; // get position.
// no need to call sei()
}
setup()
{
pinMode(pinA, INPUT_PULLUP);
pinMode(pinB, INPUT_PULLUP);
// get an initial value
encValA = digitalRead(pinA) ? 0b01 : 0;
encValA += digitalRead(pinB) ? 0b10 : 0;
// use digitalPinToInterrupt() to map interrupts to a pin #
// ask for interrupt on change, this doubles .
attachInterrupt(digitalPinToInterrupt(PIN_A), OnEncoder1Change, CHANGE);
attachInterrupt(digitalPinToInterrupt(PIN_B), OnEncoder1Change, CHANGE);
//...
}
unsigned char oldTime;
unsigned char oldPos;
int speed;
void loop()
{
unsigned char time = millis();
if (time - oldTime > 30) // pace readings so you have a reasonable value.
{
unsigned char pos = encPos1;
signed char delta = pos - oldPos;
speed = 1000 * delta) / (time - oldTime); // signed ticks/s
encPos1 -= pos; // reset using subtraction, do you don't miss out
// on any encoder pulses.
oldTime = time;
}
}
I am using a ITG3200(Sparkfun breakout board) for my project. I was trying to boost the sample rate of ITG3200 to over 2K HZ. I have already soldered two 2.2K pull-up resistors on the sensor and close the clockin pads. I encountered a few problems here. It was connected to a Arduino Uno.
The highest sample rate I can achieve was around 500 Hz. I have changed the clock to 400K. However, without doing that, I should still get something over 1000 Hz, right? I attached my code below.
Any comments or suggestions would be greatly appriecated!
#include <SPI.h>
#include <Wire.h>
// Pin definitions - Shift registers:
int enPin = 13; // Shift registers' Output Enable pin
int latchPin = 12; // Shift registers' rclk pin
int clkPin = 11; // Shift registers' srclk pin
int clrPin = 10; // shift registers' srclr pin
int datPin = 8; // shift registers' SER pin
int show = 0;
int lastMax = 0;
//This is a list of registers in the ITG-3200. Registers are parameters that determine how the sensor will behave, or they can hold data that represent the
//sensors current status.
//To learn more about the registers on the ITG-3200, download and read the datasheet.
char WHO_AM_I = 0x00;
char SMPLRT_DIV= 0x15;//0x15
char DLPF_FS = 0x16;
char GYRO_XOUT_H = 0x1D;
char GYRO_XOUT_L = 0x1E;
char GYRO_YOUT_H = 0x1F;
char GYRO_YOUT_L = 0x20;
char GYRO_ZOUT_H = 0x21;
char GYRO_ZOUT_L = 0x22;
//This is a list of settings that can be loaded into the registers.
//DLPF, Full Scale Register Bits
//FS_SEL must be set to 3 for proper operation
//Set DLPF_CFG to 3 for 1kHz Fint and 42 Hz Low Pass Filter
char DLPF_CFG_0 = 0;//1
char DLPF_CFG_1 = 0;//2
char DLPF_CFG_2 = 0;//4
char DLPF_FS_SEL_0 = 8;
char DLPF_FS_SEL_1 = 16;
char itgAddress = 0x69;
// Some of the math we're doing in this example requires the number of bargraph boards
// you have connected together (normally this is one, but you can have a maximum of 8).
void setup()
// Runs once upon reboot
{
// Setup shift register pins
pinMode(enPin, OUTPUT); // Enable, active low, this'll always be LOW
digitalWrite(enPin, LOW); // Turn all outputs on
pinMode(latchPin, OUTPUT); // this must be set before calling shiftOut16()
digitalWrite(latchPin, LOW); // start latch low
pinMode(clkPin, OUTPUT); // we'll control this in shiftOut16()
digitalWrite(clkPin, LOW); // start sck low
pinMode(clrPin, OUTPUT); // master clear, this'll always be HIGH
digitalWrite(clrPin, HIGH); // disable master clear
pinMode(datPin, OUTPUT); // we'll control this in shiftOut16()
digitalWrite(datPin, LOW); // start ser low
// To begin, we'll turn all LEDs on the circular bar-graph OFF
digitalWrite(latchPin, LOW); // first send latch low
shiftOut16(0x0000);
digitalWrite(latchPin, HIGH); // send latch high to indicate data is done sending
Serial.begin(230400);
//Initialize the I2C communication. This will set the Arduino up as the 'Master' device.
Wire.begin();
//Read the WHO_AM_I register and print the result
char id=0;
id = itgRead(itgAddress, 0x00);
Serial.print("ID: ");
Serial.println(id, HEX);
//Configure the gyroscope
//Set the gyroscope scale for the outputs to +/-2000 degrees per second
itgWrite(itgAddress, DLPF_FS, (DLPF_FS_SEL_0|DLPF_FS_SEL_1|DLPF_CFG_0));
//Set the sample rate to 100 hz
itgWrite(itgAddress, SMPLRT_DIV, 0);
}
void loop()
// Runs continuously after setup() ends
{
static int zero = 0;
// Create variables to hold the output rates.
int xRate, yRate, zRate;
float range = 3000.0;
int divisor;
divisor = range / 8;
//Read the x,y and z output rates from the gyroscope.
xRate = int(float(readX()) / divisor - 0.5) * -1;
yRate = int(float(readY()) / divisor - 0.5) * -1;
zRate = int(float(readZ()) / divisor - 0.5);
//Print the output rates to the terminal, seperated by a TAB character.
Serial.print(xRate);
Serial.print('\t');
Serial.print(yRate);
Serial.print('\t');
Serial.println(zRate);
Serial.print('\t');
// Serial.println(zero);
// fillTo(zRate);
//Wait 10ms before reading the values again. (Remember, the output rate was set to 100hz and 1reading per 10ms = 100hz.)
// delay(10);
}
// This function will write a value to a register on the itg-3200.
// Parameters:
// char address: The I2C address of the sensor. For the ITG-3200 breakout the address is 0x69.
// char registerAddress: The address of the register on the sensor that should be written to.
// char data: The value to be written to the specified register.
void itgWrite(char address, char registerAddress, char data)
{
//Initiate a communication sequence with the desired i2c device
Wire.beginTransmission(address);
//Tell the I2C address which register we are writing to
Wire.write(registerAddress);
//Send the value to write to the specified register
Wire.write(data);
//End the communication sequence
Wire.endTransmission();
}
//This function will read the data from a specified register on the ITG-3200 and return the value.
//Parameters:
// char address: The I2C address of the sensor. For the ITG-3200 breakout the address is 0x69.
// char registerAddress: The address of the register on the sensor that should be read
//Return:
// unsigned char: The value currently residing in the specified register
unsigned char itgRead(char address, char registerAddress)
{
//This variable will hold the contents read from the i2c device.
unsigned char data=0;
//Send the register address to be read.
Wire.beginTransmission(address);
//Send the Register Address
Wire.write(registerAddress);
//End the communication sequence.
Wire.endTransmission();
//Ask the I2C device for data
Wire.beginTransmission(address);
Wire.requestFrom(address, 1);
//Wait for a response from the I2C device
if(Wire.available()){
//Save the data sent from the I2C device
data = Wire.read();
}
//End the communication sequence.
Wire.endTransmission();
//Return the data read during the operation
return data;
}
//This function is used to read the X-Axis rate of the gyroscope. The function returns the ADC value from the Gyroscope
//NOTE: This value is NOT in degrees per second.
//Usage: int xRate = readX();
int readX(void)
{
int data=0;
data = itgRead(itgAddress, GYRO_XOUT_H)<<8;
data |= itgRead(itgAddress, GYRO_XOUT_L);
return data;
}
//This function is used to read the Y-Axis rate of the gyroscope. The function returns the ADC value from the Gyroscope
//NOTE: This value is NOT in degrees per second.
//Usage: int yRate = readY();
int readY(void)
{
int data=0;
data = itgRead(itgAddress, GYRO_YOUT_H)<<8;
data |= itgRead(itgAddress, GYRO_YOUT_L);
return data;
}
//This function is used to read the Z-Axis rate of the gyroscope. The function returns the ADC value from the Gyroscope
//NOTE: This value is NOT in degrees per second.
//Usage: int zRate = readZ();
int readZ(void)
{
int data=0;
data = itgRead(itgAddress, GYRO_ZOUT_H)<<8;
data |= itgRead(itgAddress, GYRO_ZOUT_L);
return data;
}
void fillTo(int place) {
int ledOutput = 0;
if(place > 8)
place = 8;
if(place < -8)
place = -8;
if(place >= 0) {
for (int i = place; i >= 0; i--)
ledOutput |= 1 << i;
} else {
ledOutput = 32768;
for (int i = place; i <= 0; i++)
ledOutput |= (ledOutput >> 1);
}
// Serial.println(ledOutput);
digitalWrite(latchPin, LOW); // first send latch low
shiftOut16(ledOutput); // send the ledOutput value to shiftOut16
digitalWrite(latchPin, HIGH); // send latch high to indicate data is done sending
}
void shiftOut16(uint16_t data)
{
byte datamsb;
byte datalsb;
// Isolate the MSB and LSB
datamsb = (data & 0xFF00) >> 8; // mask out the MSB and shift it right 8 bits
datalsb = data & 0xFF; // Mask out the LSB
// First shift out the MSB, MSB first.
shiftOut(datPin, clkPin, MSBFIRST, datamsb);
// Then shift out the LSB
shiftOut(datPin, clkPin, MSBFIRST, datalsb);
}
500Hz means 2ms for each iteration of your loop() function. Your loop function is reading from Wire and writing to the Serial port, which may take more time than 2ms, depending on what you're sending and what your baud rate is.
Judging from your baud rate (230400), it may take roughly 0.5ms to send each measurement (estimated at 12 characters each) if there is no flow control from the other side. Try writing to serial less frequently to see if your performance goes up.
I tested the serial writes, the I2C port and the clock speed. Found the major issues were the redundant communication to i2c. For instance, the 6 bits data can be read in one round of i2c communication. I refered the code below:
https://raw.githubusercontent.com/ControlEverythingCommunity/ITG3200/master/Arduino/ITG-3200.ino
In addition, using Teensy is also helpful.
The speed of the output was checked by using the oscilloscope with the I2C debug function.
I'm having some problems with some C code I'm writing for an arduino project. The goal is to digitize a large quantity of analog signals with external multiplexed ADCs, then load these digital values into an external shift register and shift them into the Arduino using SPI.To test my code I only have one ADC multiplexing 4 signals.
The interrupt pin (20) is connected to a comparator circuit which looks at the raw analog signal and pulls the pin high when the voltage is 1V or higher. When the ISR is called it will disable global interrupts "noInterrupts()" set an event flag, detach pin 20 from the interrupt handler, enable global interrupts "interrupts()" and finally return to where it left off.
I'm facing a couple issues, first the ISR is called once fine, a second time fine but after the second ISR call it is not called again untill, which is my seconds issue, the interrupt pin goes low. As per the AttachInterupt() function the ISR should only be called when pin 20 is high. This can be seen in the first and second picture I have attached. Another thing I notice is that the duration that the interrupt pin is high has no effect on whether a 3rd ISR is called.
I'm not sure if this is an issue with my understanding of the interrupt-handling of the Arduino, or a code screw up resulting in a stack overflow or something like that.
// the sensor communicates using SPI, so include the library:
#include <SPI.h>
//Constants
#define RD 41 //pin 41 conneced to read pin
#define INT1 37 //pin 37 connecte to interrupt 1
#define CLK_INH 53 //pin 53 connected to clk inhibit
#define LD 40 //pin 40 connected to load pin
#define INPUT_MAX 3 //input selector limit (Zero Indexed)
#define SENSORS 3 //how many sensors are used (Zero Indexed)
#define DATA_DUMP 38 //pin 29 controlls the data dump deature
#define BYTE_LEN 1 //number of ADC used
#define DEBUG1 17
#define DEBUG2 16
//Controls
unsigned char selector = 0; //ACD input selector
volatile byte eventFlag = LOW; //Control Flag, set to True when event occurs
bool lastButtonState = true;
//Counters
unsigned int i = 0; //eventLog[i]: event counter
unsigned int j = 0; //eventLog[i].data[j]: data counter
//Function Delcarations
unsigned char inputSelector (unsigned char my_selector);
void lockAndPop ();
void dataDump ();
void debug (int pin);
bool fallingEdge (bool); //check for a falling edge of a digital read
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void setup() {
// put your setup code here, to run once:
pinMode(RD, OUTPUT); //Read pin, 0 = begin analog conversion (ADC)
pinMode(INT1, INPUT); //Interrupt pin, 0 = conversion complete (ADC)
pinMode(CLK_INH, OUTPUT); //Clock inhibit pin, 1= no change on output (ShiftRegister)
pinMode(LD, OUTPUT); //Shift/Load pin, 1 = data is shifted (ShiftRegister)
pinMode(DATA_DUMP, INPUT);
pinMode(DEBUG1, OUTPUT);
pinMode(DEBUG2, OUTPUT);
DDRA = 0xFF; //Set port A to ouput
SPI.begin();
//SPI.mode1 Clock idel low CLOP = 0, Data sampled on falling edge CPHA = 1
SPI.beginTransaction(SPISettings(5000000, MSBFIRST, SPI_MODE1));
digitalWrite(RD, HIGH); //Stop conversion
digitalWrite(CLK_INH, HIGH); //No change on the output
digitalWrite(LD, LOW); //Load the shift register
digitalWrite(DEBUG1, LOW);
digitalWrite(DEBUG2, LOW);
attachInterrupt(digitalPinToInterrupt(20), pin_ISR, HIGH); //Call pin_ISR when pin20 goes high
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
typedef struct //event structure, containts a timestamp element and an array of 18 data points
{
unsigned long int timeStamp;
unsigned char data[SENSORS];
} Event;
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
Event eventLog[200]; //an array of structures representing 200 events, once the 200 events have been filled the data will be printed
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void loop() {
if(fallingEdge(digitalRead(DATA_DUMP))){ //If there is falling edge on the data dump button, call the dataDump function
dataDump();
}
debug(DEBUG2);
if(eventFlag) //if the Event flag is set to true by ISR begin the conversion steps
{
debug(DEBUG1);
digitalWrite(RD,LOW); //Start conversion
while(digitalRead(INT1)){} //Wait for conversion to complete
eventLog[i].timeStamp = micros();
for (j=0; j<=SENSORS; j++) {
lockAndPop(); //lock digital value and reset conversion
PORTA = inputSelector(selector); //increment the selector pin
digitalWrite(RD, LOW); //Start new conversion
digitalWrite(CLK_INH, LOW); //Start the data transfer
eventLog[i].data[j] = SPI.transfer(0); //read a single byte from the SPI line
digitalWrite(CLK_INH, HIGH); //Inhibit clock
digitalWrite(LD, LOW);
while(digitalRead(INT1)){} //wait for previous conversion to end
}
i++;
digitalWrite(RD, HIGH);
selector = 0;
if(i>=200){
dataDump(); //if the event log hits 200 before a data dump is request, dump the data
}
eventFlag = LOW;
attachInterrupt(digitalPinToInterrupt(20), pin_ISR, HIGH);
}
}
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void pin_ISR() {
noInterrupts();
detachInterrupt(digitalPinToInterrupt(20));
eventFlag = HIGH;
interrupts();
return;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
unsigned char inputSelector (unsigned char my_selector){
if(my_selector==INPUT_MAX){ //if the current selector is at the highest value reset to 0
return 0;
}
return my_selector++; //increment the input selector by 1
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void lockAndPop (){
digitalWrite(LD, HIGH); //Lock in digital value
digitalWrite(RD, HIGH); //Reset conversion
return;
}
void dataDump (){
detachInterrupt(digitalPinToInterrupt(20));
char buf[100], *pos = buf; //create a buffer of 100 charaters, anda pointer to the begining of that buffer
char *base = buf; //create a base address to reset the buffer
unsigned int eventCount = i; //how many events occured before dump command was called
unsigned int localCount;
unsigned int localData;
Serial.begin(115200);
Serial.println(i);
for (localCount = 0; localCount<=eventCount; localCount++){
pos += sprintf(pos, "%lu", eventLog[localCount].timeStamp); //sprintf will append the data to the pointer "pos", and return the number of byte append.
for (localData = 0; localData<=SENSORS; localData++){
pos += sprintf(pos, " %d", (unsigned int)(eventLog[localCount].data[localData]));
}
Serial.println(buf);
pos = base;
}
i=0;
j=0;
Serial.end();
attachInterrupt(digitalPinToInterrupt(20), pin_ISR, HIGH);
return;
}
void debug(int pin){
digitalWrite(pin, HIGH);
digitalWrite(pin, LOW);
return;
}
bool fallingEdge (bool currentButtonState){
if(!currentButtonState&&lastButtonState){
lastButtonState = currentButtonState;
return 1;
}
lastButtonState = currentButtonState;
return 0;
}
There is a bit of noise happening on the ISR pin, but this shouldn't matter as I'm disabled that particular pin within the service routine so I wouldn't think this is an issue