Faulty Arduino Logic? - serialization

I am making a simple Led program that will be turned into a library for my project. I have created four methods that will allow you to A) Setup as many Led pins as you want and make them as Outputs. B) Flash the Led lights at a customized time. C) Turn On Leds. D) Turn Off Leds. Everything is working if i just run the methods in the void loop(). For example:
Void loop(){
flashLed(pinNum, 2000);
turnOf(pinNum);
turnOn(pinNum);
}
If i run the above code it works fine, however it keeps looping as its obviously in a loop. So i decided to start the serial com by using Serial.begin(9600) in the setup(), and then testing for the serial com and used a switch case statement in order to appropriately implement these methods. What am i doing wrong here? i get no errors at all. When i type into the serial monitor nothing happens, i believe my logic is fine but that is why i am here. When anything is typed into the serial monitor, the code runs the default in the switch case statement and that is all. I have tried using while, if to no avail. Also tested the inverse of serial which would be !serial.available() Here is my code:
//Define the pin numbers
byte pinNum[] = {4, 3, 2};
void setup() {
//Setup the ledPins
ledSetup(pinNum);
Serial.begin(9600);
}
void loop() {
while(Serial.available() > 0){
//Read the incoming byte
byte ledStatus = Serial.read();
switch (ledStatus){
case 0:
turnOff(pinNum);
Serial.println("The Leds Have Been Turned Off");
break;
case 1:
turnOn(pinNum);
Serial.println("The Leds Have Been Turned On");
break;
case 2:
flashLed(pinNum, 1000); //This will make the Led blink for half a second
Serial.println("The Leds Will Begin Flashing");
break;
default:
flashLed(pinNum, 1000); //This will make the Led blink for half a second
break;
}
}
}
//Method to declare the pins as output
void ledSetup(byte ledPins[]){
for (int i = 0; i <= sizeof(ledPins); i++){
pinMode(ledPins[i], OUTPUT);
}
}
//Method to blink the Led light/lights
void flashLed(byte ledBlink[], int duration){
//Time is divided by two because it takes 2 seconds
//to run the sketch
for (int i = 0; i <= sizeof(ledBlink); i++){
digitalWrite(ledBlink[i], HIGH);
delay(duration/2);
digitalWrite(ledBlink[i], LOW);
delay(duration/2);
}
}
//Method to turn Leds off
void turnOff(byte ledOff[]){
for(int i = 0; i <= sizeof(ledOff); i++){
digitalWrite(ledOff[i], LOW);
}
}
//Method to turn Leds On
void turnOn(byte turnOn[]){
for (int i = 0; i <= sizeof(turnOn); i ++){
digitalWrite(turnOn[i], HIGH);
}
}

The serial monitor sends symbols encoded in the ASCII format.
e.g. when you enter 0, Serial.read() returns 48, which is the ASCII code for digit 0. Since the value 48 is not listed in the following cases, the default branch is taken:
case 0: ...
case 1: ...
case 2: ...
default: ...
There are many solutions to your problem.
1. change case conditions to match what you are sending:
case '0': ...
case '1': ...
case '2': ...
2. replace Serial.read() with Serial.parseInt():
int ledStatus = Serial.parseInt();
This will actually work with more general inputs, e.g. 123, but it will return 0 if there is anything different from a digit in the input buffer.
3. wrap Serial.read() within atoi():
byte ledStatus = atoi(Serial.read());
This is somewhat more limited than both of previous options, since now you can only have 10 cases in your switch.

Related

STM32 Crash on Flash Sector Erase

I'm trying to write 4 uint32's of data into the flash memory of my STM32F767ZI so I've looked at some examples and in the reference manual but still I cannot do it. My goal is to write 4 uint32's into the flash and read them back and compare with the original data, and light different leds depending on the success of the comparison.
My code is as follows:
void flash_write(uint32_t offset, uint32_t *data, uint32_t size) {
FLASH_EraseInitTypeDef EraseInitStruct = {0};
uint32_t SectorError = 0;
HAL_FLASH_Unlock();
EraseInitStruct.TypeErase = FLASH_TYPEERASE_SECTORS;
EraseInitStruct.VoltageRange = FLASH_VOLTAGE_RANGE_3;
EraseInitStruct.Sector = FLASH_SECTOR_11;
EraseInitStruct.NbSectors = 1;
//EraseInitStruct.Banks = FLASH_BANK_1; // or FLASH_BANK_2 or FLASH_BANK_BOTH
st = HAL_FLASHEx_Erase(&EraseInitStruct, &SectorError);
if (st == HAL_OK) {
for (int i = 0; i < size; i += 4) {
st = HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, FLASH_USER_START_ADDR + offset + i, *(data + i)); //This is what's giving me trouble
if (st != HAL_OK) {
// handle the error
break;
}
}
}else {
// handle the error
}
HAL_FLASH_Lock();
}
void flash_read(uint32_t offset, uint32_t *data, uint32_t size) {
for (int i = 0; i < size; i += 4) {
*(data + i) = *(__IO uint32_t*)(FLASH_USER_START_ADDR + offset + i);
}
}
int main(void) {
uint32_t data[] = {'a', 'b', 'c', 'd'};
uint32_t read_data[] = {0, 0, 0, 0};
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
flash_write(0, data, sizeof(data));
flash_read(0, read_data, sizeof(read_data));
if (compareArrays(data,read_data,4))
{
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7,SET);
}
else
{
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_14,SET);
}
return 0;
}
The problem is that before writing data I must erase a sector, and when I do it with the HAL_FLASHEx_Erase(&EraseInitStruct, &SectorError), function, the program always crashes, and sometimes even corrupts my codespace forcing me to update firmware.
I've selected the sector farthest from the code space but still it crashes when i try to erase it.
I've read in the reference manual that
Any attempt to read the Flash memory while it is being written or erased, causes the bus to
stall. Read operations are processed correctly once the program operation has completed.
This means that code or data fetches cannot be performed while a write/erase operation is
ongoing.
which I believe means the code should ideally be run from RAM while we operate on the flash, but I've seen other people online not have this issue so I'm wondering if that's the only problem I have. With that in mind I wanted to confirm if this is my only issue, or if I'm doing something wrong?
In your loop, you are adding multiples of 4 to i, but then you are adding i to data. When you add to a pointer it is automatically multiplied by the size of the pointed type, so you are adding multiples of 16 bytes and reading past the end of your input buffer.
Also, make sure you initialize all members of EraseInitStruct. Uncomment that line and set the correct value!

While loop before if-else statement not working?

I have a code illuminating an LED using a few different inputs. I'm not sure why but the (while) command to turn off the light when the battery is low, isn't executing. Currently it's draining below the 3v level all the way down to 1.9v. Could it be because of my code structure?
While- measures battery and shuts off when under 3v
if (rf95.available())- listens for a radio signal and switch command
if(digitalRead(SWITCH))- listens for physical switch command
else- leaves the LED on if no commands are sent
Watchdog.sleep- deep sleep command to save battery
void loop(){
Serial.begin(115200);
uint8_t buf[RH_RF95_MAX_MESSAGE_LEN];
uint8_t len = sizeof(buf);
float measuredvbat = analogRead(VBATPIN);
measuredvbat *= 2; // we divided by 2, so multiply back
measuredvbat *= 3.3; // Multiply by 3.3V, our reference voltage
measuredvbat /= 1024; // convert to voltage
measuredvbat /=1.61; // fudge factor
Serial.print("VBat: " );
Serial.println(measuredvbat);
while(measuredvbat < 3.00){
analogWrite(LED,0);
Serial.print("VBat: " );
Serial.println(measuredvbat);
Serial.println("Battery Low");
int sleepMS = Watchdog.sleep(3600000);
}
if (rf95.available()){
if (rf95.recv(buf, &len)) {
if(strncmp(buf, "TurnOn", strlen(buf)) == 0){
Serial.println("Turn Up For WAT !!");
analogWrite(LED,75);
}
}
}
if(digitalRead(SWITCH)){
Serial.println("SWITCH-ON-12");
analogWrite(LED, 75);
}
else{
Serial.println("SWITCHED ON-12");
analogWrite(LED, 112);
}
}

What is the best way to detect a button push - Arduino

I have a function which is basically a Whack-A-Mole game using LEDs and Push Buttons. LED-A lights up, and the user has to push BTN-A to turn it off... and we move on to the next LED/BTN combo.
My circuitry works and i can turn each LED on/off individually and detect each button push as well. However, once in my game loop (see below), I see some odd behavior.
My code looks like this:
void gameTwo(){
Serial.println("We are in Game 2");
playGameTwo();
//lightShowTwo();
// Set game state
int gameState = 0;
// Start counter
elapsedMillis timeElapsed;
// First LED
digitalWrite(ledB, HIGH);
while(digitalRead(btnB) != HIGH){
//Serial.print("btnBstate is: ");
//Serial.println(digitalRead(btnB));
if(digitalRead(btnB) == 1){
delay(50);
digitalWrite(ledB, LOW);
Serial.print(timeElapsed);
}
}
// Second LED
digitalWrite(ledE, HIGH);
while(digitalRead(btnE) != HIGH){
//Serial.print("btnBstate is: ");
//Serial.println(digitalRead(btnE));
if(digitalRead(btnE) == 1){
delay(50);
digitalWrite(ledE, LOW);
Serial.print(timeElapsed);
}
}
// Third LED
digitalWrite(ledF, HIGH);
while(digitalRead(btnF) != HIGH){
//Serial.print("btnBstate is: ");
//Serial.println(digitalRead(btnE));
if(digitalRead(btnF) == 1){
delay(50); // these dalays DO NOT work
digitalWrite(ledF, LOW);
Serial.print(timeElapsed);
}
}
// End Game - Publish Elapsed Time
gameState = 1;
// record user's elapsed time
int userTime = timeElapsed;
Serial.print("Game Finished - Your time was: ");
Serial.print(timeElapsed);
Serial.println(" ms!");
}
The problem is that it doesn't always work. Sometimes LED-A turn off, sometimes it stays on.
As you can see, I've tried adding a small delay(50) also to no avail.
What is the best way to detect button presses in a while loop.
Bonus question: I'm hard coding the game (eg LEDA, LEDB... LEDx). There should be a better way, perhaps using an array, to push the game sequence. As I'm not a programmer, I'd appreciate some guidance or an article to read to get more educated on this. Thanks.
You can use while to loop until a button is pressed.
Using arrays will make it much easier, here I use an array for leds and a another for buttons. The numbers in arrays represents the pins. I inserted random() function that will make it more challenging. Each loop it takes a random ledPin for led[] and a corresponding btnPin for btn[].
//suppose that the button in pin 4 is for led in pin 1
//the button in pin 5 is for led in pin 2
//and the button in pin 6 is for led in pin 3
int led[] = {1, 2, 3};
int btn[] = {4, 5, 6};
int count = 3;
int ledPin = 0;
int btnPin = 0;
int previous = 0;
void setup() {
for( ledPin=0; ledPin<count; ledPin++ ){
pinMode(led[ledPin], OUTPUT);
}
}
void loop() {
ledPin = random(1, 4); //pick a random number 1-3
while( ledPin == previous ){ //if it is the same as previous, change it
ledPin = random(3); }
btnPin = ledPin + 3; //btnPin set to 4-6
digitalWrite(led[ledPin], HIGH);
while( digitalRead(btn[btnPin]) == LOW ){} //or HIGH according to pulling method
digitalWrite(led[ledPin],LOW);
previous = ledPin;
}

pic Interrupt on change doesn't trigger first time

I'm trying to comunicate a pic18f24k50 with an arduino 101. I'm using two lines to establish a synchronized comunication. On every change from low to high of the first line, I read the value from the second line.
I have no problems with the arduino code, my problem is that in the pic, the Interrupt on change triggers on the second change from low to high instead of triggering on the first change. This only happens the first time I send data, after that, it works perfectly (it triggers on the first change and I receive the byte properly). Sorry for my english, I'll try to explain myself better with this image:
Channel 1 is the clock signal, channel2 is the data (Im sending one byte for the moment, with bit values 10101010). Channel 4 is an output I'm changing every time I process a bit. (as you can see, it begins on the second rise of the clock signal instead of the first one). This is captured on the first sent byte, the next ones works ok.
I post the relevant code in the pic here:
This is where I initialize things:
TRISCbits.TRISC6 = 0;
TRISCbits.TRISC1 = 1;
TRISCbits.TRISC2 = 1;
IOCC1 = 1;
ANSELCbits.ANSC2=0;
IOCC2 = 0;
INTCONbits.IOCIE = 1;
INTCONbits.IOCIF = 0;
And this is on the interrupt code:
void interrupt SYS_InterruptHigh(void)
{
if (INTCONbits.IOCIE==1 && INTCONbits.IOCIF==1)
{
readByte();
}
}
void readByte(void)
{
while(contaBits<8)
{
INTCONbits.IOCIE = 0;
INTCONbits.IOCIF = 0;
while (PORTCbits.RC1 != HIGH)
{
}
if (PORTCbits.RC1 == HIGH)
{
LATCbits.LATC6 = !LATCbits.LATC6;
//LATCbits.LATC6 = ~LATCbits.LATC6;
switch (contaBits)
{
case 0:
if (PORTCbits.RC2 == HIGH)
varByte.b0 = 1;
else
varByte.b0 = 0;
break;
case 1:
if (PORTCbits.RC2 == HIGH)
varByte.b1 = 1;
else
varByte.b1 = 0;
break;
case 2:
if (PORTCbits.RC2 == HIGH)
varByte.b2 = 1;
else
varByte.b2 = 0;
break;
case 3:
if (PORTCbits.RC2 == HIGH)
varByte.b3 = 1;
else
varByte.b3 = 0;
break;
case 4:
if (PORTCbits.RC2 == HIGH)
varByte.b4 = 1;
else
varByte.b4 = 0;
break;
case 5:
if (PORTCbits.RC2 == HIGH)
varByte.b5 = 1;
else
varByte.b5 = 0;
break;
case 6:
if (PORTCbits.RC2 == HIGH)
varByte.b6 = 1;
else
varByte.b6 = 0;
break;
case 7:
if (PORTCbits.RC2 == HIGH)
varByte.b7 = 1;
else
varByte.b7 = 0;
break;
}
contaBits++;
}
}//while(contaBits<8)
INTCONbits.IOCIE = 1;
contaBits=0;
}
LATCbits.LATC6 = !LATCbits.LATC6; <-- this is the line corresponding to channel 4.
RC1 is channel 1
and RC2 is channel 2
My question is what am I doing wrong, why on the first sent of bytes the interrupt doesn't triggers on the first change of the line 1?
Thank you.
What are you trying to achieve?
The communication protocol as you're describing is commonly refered to as SPI (Serial Peripheral Interface). You should use the hardware implementation available by PIC/Microchip, if possible, for best performance.
Keep your code documented/formatted/logic
I noticed your code being a little, weird.
Weird code gives weird errors.
First:
You're using interrupts, you have this blocking code in your interrupt. Which isn't nice at all.
Second:
Your "contabits" and "varByte" variable come out of nowhere, probably they're global. Which might not be the best practice.
Though, if you're using interrupts, and when it might make sense to transfer the variables to your main program by using a global. The global should be volatile.
Third:
That case switch is just 8x the same code, but a little different.
Also, add some comments to your code.
To be honest
I didn't spot your actual error, has been a long time since I worked with PIC.
But, you should try hardware SPI.
Below is my attempt at software SPI as you described, it might be a little more logical, and takes out any annoyance of the interrupts.
I would recommend replacing the while(CLOCK_PIN_MACRO != 1){}; with for(unsigned int timeout = 64000; timeout > 0; timeout--){};.
So that you can be sure your program won't hang while waiting for an SPI signal that won't come. (Make the timeout something what fits your needs)
#define CLOCK_PIN_MACRO PORTCbits.RC1
#define DATA_PIN_MACRO PORTCbits.RC2
/*
Test, without interrupts.
I would strongly advise to use Hardware SPI or non-blocking code.
*/
unsigned char readByte(void){
unsigned char returnByte = 0;
for(int i = 0; i < 8; i++){ //Do this for bit 0 to 7, to get a complete byte.
while(CLOCK_PIN_MACRO != 1){}; //Wait until the Clock pin goes high.
if(DATA_PIN_MACRO == 1) //Check the data pin.
returnByte = returnByte & (1 << i); //Shift the bit in our byte. (https://www.cs.umd.edu/class/sum2003/cmsc311/Notes/BitOp/bitshift.html)
while(CLOCK_PIN_MACRO == 1){}; //Wait untill the Clock pin goes low again.
}
return returnByte;
}
void setup(){
TRISCbits.TRISC6 = 0;
TRISCbits.TRISC1 = 1;
TRISCbits.TRISC2 = 1;
//IOCC1 = 1;
ANSELCbits.ANSC2=0;
//IOCC2 = 0;
INTCONbits.IOCIE = 1;
INTCONbits.IOCIF = 0;
}
void run(){
unsigned char theByte = readByte();
}
main(){
setup();
while(1){
run();
}
}
You can find the following from the datasheet.
The pins are compared with the old value latched on the last read of
PORTB. The "mismatch" outputs of RB7:RB4 are ORed together to generate
the RB Port Change Interrupt with Flag bit,RBIF (INTCON<0>).
This means that when you read PORTB RB7:RB4 pins, the value of each pin will be stored in an internal latch. Interrupt will be generated only when there is any change in the pin input from the previously latched value.
Then, what will be the default initial value in the latch? i.e. Before we read anything from PORTB.
What ever it is. in your case the default latch value is different from the logic state of your input signal. During the next transition of the signal the latch value and signal level becomes same. So no intterrupt is generated first time.
What you can do is setting the latch value to the initial state of your signal. This can be done by reading PORTB (should be done before enabling the intterrupt).
The below code is enough to simply read the register.
unsigned char ch;
ch = PORTB;
Hope this will help.

Traffic lights simulation and xbee communication

So i am having this project. The system will give priority to emergency vehicles when they get close to traffic lights and when they get close i want to change the state of the traffic lights from red to green but in correct sequence.
I have managed to pull it off but it doesnt work with a real car because the xbees (coordinator on the vehicle and end device on home-made traffic lights) take sometime to communicate which is not enough for the speed of a vehicle approaching traffic lights with lets say an average speed of 60km/h.
The system works like this. There is an arduino on the vehicle which has a GPS shield and an xbee set to COORDINATOR on it. In the program on the arduino it checks if the gps reads coordinates that are saved inside the arduino so it checks against real time coordinates and if they match, the xbee gets to send a message across to the corresponding xbees that are set as end-devices on the traffic lights which again setup is arduino + xbee.
The problem 1 is i need to make a faster connection between the xbees (COORDINATOR - END DEVICE)
Here is the arduino sketch for ARDUINO-GPS-COORDINATOR. Note: GPS Shield is from adafruit and i use their code plus some of mine.
// Test code for Adafruit GPS modules using MTK3329/MTK3339 driver
//
// This code shows how to listen to the GPS module in an interrupt
// which allows the program to have more 'freedom' - just parse
// when a new NMEA sentence is available! Then access data when
// desired.
//
// Tested and works great with the Adafruit Ultimate GPS module
// using MTK33x9 chipset
// ------> http://www.adafruit.com/products/746
// Pick one up today at the Adafruit electronics shop
// and help support open source hardware & software! -ada
#include <Adafruit_GPS.h>
#include <SoftwareSerial.h>
SoftwareSerial mySerial(10, 11);
SoftwareSerial xbee(13,12);
// If using hardware serial (e.g. Arduino Mega), comment out the
// above SoftwareSerial line, and enable this line instead
// (you can change the Serial number to match your wiring):
//HardwareSerial mySerial = Serial1;
Adafruit_GPS GPS(&mySerial);
// Set GPSECHO to 'false' to turn off echoing the GPS data to the Serial console
// Set to 'true' if you want to debug and listen to the raw GPS sentences.
#define GPSECHO true
// this keeps track of whether we're using the interrupt
// off by default!
boolean usingInterrupt = false;
void useInterrupt(boolean); // Func prototype keeps Arduino 0023 happy
void setup()
{
Serial.begin(115200);
Serial.println("Adafruit GPS library basic test!");
xbee.begin(9600);
xbee.println("SoftwareSerial on coordinator working!");
GPS.begin(9600);
// uncomment this line to turn on RMC (recommended minimum) and GGA (fix data) including altitude
GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA);
// uncomment this line to turn on only the "minimum recommended" data
//GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCONLY);
// For parsing data, we don't suggest using anything but either RMC only or RMC+GGA since
// the parser doesn't care about other sentences at this time
// Set the update rate
GPS.sendCommand(PMTK_SET_NMEA_UPDATE_1HZ); // 1 Hz update rate
// For the parsing code to work nicely and have time to sort thru the data, and
// print it out we don't suggest using anything higher than 1 Hz
// Request updates on antenna status, comment out to keep quiet
GPS.sendCommand(PGCMD_ANTENNA);
// the nice thing about this code is you can have a timer0 interrupt go off
// every 1 millisecond, and read data from the GPS for you. that makes the
// loop code a heck of a lot easier!
useInterrupt(true);
delay(1000);
// Ask for firmware version
mySerial.println(PMTK_Q_RELEASE);
}
// Interrupt is called once a millisecond, looks for any new GPS data, and stores it
SIGNAL(TIMER0_COMPA_vect) {
char c = GPS.read();
// if you want to debug, this is a good time to do it!
#ifdef UDR0
if (GPSECHO)
if (c) UDR0 = c;
// writing direct to UDR0 is much much faster than Serial.print
// but only one character can be written at a time.
#endif
}
void useInterrupt(boolean v) {
if (v) {
// Timer0 is already used for millis() - we'll just interrupt somewhere
// in the middle and call the "Compare A" function above
OCR0A = 0xAF;
TIMSK0 |= _BV(OCIE0A);
usingInterrupt = true;
} else {
// do not call the interrupt function COMPA anymore
TIMSK0 &= ~_BV(OCIE0A);
usingInterrupt = false;
}
}
// difference_ratio
float diff_ratio = 0.010;
// COORDINATES INDEX
float coord_lat = 23;
float coord_lon = 23;
uint32_t timer = millis();
void loop() // run over and over again
{
// in case you are not using the interrupt above, you'll
// need to 'hand query' the GPS, not suggested :(
if (! usingInterrupt) {
// read data from the GPS in the 'main loop'
char c = GPS.read();
// if you want to debug, this is a good time to do it!
if (GPSECHO)
if (c) Serial.print(c);
}
// if a sentence is received, we can check the checksum, parse it...
if (GPS.newNMEAreceived()) {
// a tricky thing here is if we print the NMEA sentence, or data
// we end up not listening and catching other sentences!
// so be very wary if using OUTPUT_ALLDATA and trytng to print out data
//Serial.println(GPS.lastNMEA()); // this also sets the newNMEAreceived() flag to false
if (!GPS.parse(GPS.lastNMEA())) // this also sets the newNMEAreceived() flag to false
return; // we can fail to parse a sentence in which case we should just wait for another
}
// if millis() or timer wraps around, we'll just reset it
if (timer > millis()) timer = millis();
// approximately every 2 seconds or so, print out the current stats
if (millis() - timer > 2000) {
timer = millis(); // reset the timer
Serial.print("\nTime: ");
Serial.print(GPS.hour, DEC); Serial.print(':');
Serial.print(GPS.minute, DEC); Serial.print(':');
Serial.print(GPS.seconds, DEC); Serial.print('.');
Serial.println(GPS.milliseconds);
Serial.print("Date: ");
Serial.print(GPS.day, DEC); Serial.print('/');
Serial.print(GPS.month, DEC); Serial.print("/20");
Serial.println(GPS.year, DEC);
Serial.print("Fix: "); Serial.print((int)GPS.fix);
Serial.print(" quality: "); Serial.println((int)GPS.fixquality);
if (GPS.fix) {
//Serial.print("Location: ");
//Serial.print(GPS.latitude, 4); Serial.print(GPS.lat);
//Serial.print(", ");
//Serial.print(GPS.longitude, 4); Serial.println(GPS.lon);
Serial.print("Location (in degrees, works with Google Maps): ");
Serial.print(GPS.latitudeDegrees, 4);
Serial.print(", ");
Serial.println(GPS.longitudeDegrees, 4);
//Serial.print("Speed (knots): "); Serial.println(GPS.speed);
//Serial.print("Angle: "); Serial.println(GPS.angle);
//Serial.print("Altitude: "); Serial.println(GPS.altitude);
//Serial.print("Satellites: "); Serial.println((int)GPS.satellites);
if(GPS.latitudeDegrees + diff_ratio >= coord_lat && coord_lat >= GPS.latitudeDegrees - diff_ratio) {
if(GPS.longitudeDegrees + diff_ratio >= coord_lon && coord_lon >= GPS.longitudeDegrees - diff_ratio){
Serial.println("location OKAY");
xbee.println("K");
}
}
//if((float)GPS.latitude > (home_lat - diff_ratio) && (float)
}
}
}
The important part is where it says if(GPS.fix()) and later on.
And here is the sketch for the traffic light simulation which if it receives the message "K" it will stay to green light until it does not receive it anymore.
#include <SoftwareSerial.h>
SoftwareSerial xbee(3,2);
int greenled = 8; //Led's and pins
int yellowled = 9;
int redled = 10;
int ard_led = 13;
void setup(){
pinMode(greenled,OUTPUT);
pinMode(yellowled, OUTPUT);
pinMode(redled, OUTPUT);
pinMode(ard_led,OUTPUT);
Serial.begin(9600);
xbee.begin(9600);
}
void loop(){
delay(700);
if(xbee.available() > 0 && xbee.read() == 'K' && digitalRead(ard_led) == 0){
//Serial.println("second block");
digitalWrite(redled,HIGH);
delay(1000);
digitalWrite(yellowled, HIGH); //Yellow and red on for 2 seconds
digitalWrite(ard_led,HIGH);
}else if(xbee.available() > 0 && xbee.read() == 'K' && digitalRead(ard_led) == 1){
//Serial.println("third block");
blinking_green();
}
else if(!xbee.available() && xbee.read() != 'K' && digitalRead(greenled) == 0){
//Serial.println("first block");
digitalWrite(redled, HIGH);
delay(1000);
digitalWrite(yellowled, HIGH); //Yellow and red on for 2 seconds
delay(1000);
digitalWrite(redled, LOW); //Red and Yellow off
digitalWrite(yellowled, LOW);
digitalWrite(greenled, HIGH); //Green on for 5 seconds
delay(3000);
digitalWrite(greenled, LOW); //Green off, yellow on for 2 seconds
digitalWrite(yellowled, HIGH);
delay(1000);
digitalWrite(yellowled,LOW);
digitalWrite(redled,HIGH);
} else if(!xbee.available() && xbee.read() != 'K' && digitalRead(greenled) == 1 && digitalRead(yellowled == 0)){
//Serial.println("fourth block");
digitalWrite(greenled,LOW);
digitalWrite(yellowled, HIGH);
delay(1000);
digitalWrite(yellowled, LOW);
digitalWrite(redled,HIGH);
digitalWrite(ard_led,LOW);
}
}
void blinking_green(){
digitalWrite(redled, LOW); //Red and Yellow off
digitalWrite(yellowled, LOW);
digitalWrite(greenled,HIGH);
delay(2500);
}
Problem 2: How can i interrupt the traffic lights simulation instantly when it receives a message from a nearby arduino to change the traffic light to green BEFORE it finishes that loop? Because in a real example green and red light would say for over 20 seconds.
Question: Will a faster baud rate on the xbees achieve faster xbee communication?
thank you in advance
You need to change the loop() on your traffic light simulation. Have a variable you use to store the "state" of the light, along with a timer to keep track of when the next state change happens. This way, your loop can also check the XBee serial input every time around.
if (xbee_event_happened()) {
set_leds_off();
timer = millis();
state = STATE_FLASH_GREEN_OFF;
}
switch (state) {
case STATE_FLASH_GREEN_OFF:
if (millis() - timer > 1000) {
set_leds_green();
state = STATE_FLASH_GREEN_ON;
timer = millis();
}
break;
case STATE_FLASH_GREEN_ON:
if (millis() - timer > 1000) {
set_leds_off();
state = STATE_FLASH_GREEN_OFF;
timer = millis();
}
break;
case STATE_RED:
if (millis() - timer > 5000) {
set_leds_green();
state = STATE_GREEN;
timer = millis();
}
break;
case STATE_GREEN:
if (millis() - timer > 3000) {
set_leds_yellow();
state = STATE_YELLOW;
timer = millis();
}
break;
// etc.
}
This just covers the basics, but it shows an important aspect of loop() function design -- it should never run for more than a few milliseconds. Don't have a delay inside of your main loop, track the state of the device and then use logic to decide if the state needs to change on that pass of the loop.
Additionally, use higher baud rates when possible to avoid latency from serial transmissions, get rid of the 700ms delay in your loop, and organize your if/else structure better:
if (xbee.available() > 0) {
character = xbee.read();
if (character == 'K') {
if (digitalRead(ard_led)) {
// second block
} else {
// third block
}
} else if (character == 'X') {
// do something different? Vehicle left area?
}
}