simple communication between AtTiny85 and Arduino (I2C) - arduino

Hi I want to connect the arduino pro mini to my AtTiny85 over I2C.
The arduino should tell the attiny to switch a LED on or off.
The arduino manages to switch the led on my attiny on but it never goes off.
I don't have any clue why?
Here is my Code for master and slave:
MASTER:
#include <Wire.h>
#define device (1)
void setup() {
// put your setup code here, to run once:
Wire.begin();
}
void loop() {
// put your main code here, to run repeatedly:
Wire.beginTransmission(device);
Wire.write(1);
Wire.endTransmission();
delay(2000);
Wire.write(0);
Wire.endTransmission();
delay(2000);
}
SLAVE:
#include <TinyWireS.h>
#include <usiTwiSlave.h>
#define output (4)
#define I2C_SLAVE_ADDR (1)
void setup() {
// put your setup code here, to run once:
TinyWireS.begin(I2C_SLAVE_ADDR);
pinMode(output, OUTPUT);
}
volatile byte msg = 0;
void loop() {
if(TinyWireS.available())
msg = TinyWireS.receive();
if(msg == 1)
digitalWrite(output, HIGH);
else if(msg == 0)
digitalWrite(output, LOW);
else
msg = 0;
}

I finally found my mistake:
when I do: Wire.write(0); I forgot to start the transmission with: Wire.beginTransmission(device);

Related

Could not find a valid MPU6050 sensor

I am using the below code with arduino-uno, but often getting "Could not find a valid MPU6050 sensor
#include <Wire.h>
#include <MPU6050.h>
MPU6050 mpu;
void setup() {
Serial.begin(115200);
Serial.println("Initialize MPU6050");
while (!mpu.begin()) {
Serial.println("Could not find a valid MPU6050 sensor, check wiring!");
delay(500);
}
}
void loop() {
}
My Arduino is working fine,
So, I checked MPU6050 using below code,
#include <Wire.h>
void setup()
{
Wire.begin();
Serial.begin(115200);
while (!Serial); // Leonardo: wait for serial monitor
Serial.println("\nI2C Scanner");
}
void loop()
{
byte error, address;
int nDevices;
Serial.println("Scanning...");
nDevices = 0;
for(address = 1; address < 127; address++ )
{
// The i2c_scanner uses the return value of
// the Write.endTransmisstion to see if
// a device did acknowledge to the address.
Wire.beginTransmission(address);
error = Wire.endTransmission();
if (error == 0)
{
Serial.print("I2C device found at address 0x");
if (address<16)
Serial.print("0");
Serial.print(address,HEX);
Serial.println(" !");
nDevices++;
}
else if (error==4)
{
Serial.print("Unknown error at address 0x");
if (address<16)
Serial.print("0");
Serial.println(address,HEX);
}
}
if (nDevices == 0)
Serial.println("No I2C devices found\n");
else
Serial.println("done\n");
delay(5000); // wait 5 seconds for next scan
}
Got Output as expected
Scanning...
I2C device found at address 0x68 !
done
From the above output I hope GPU6050 is working
How can I get values from GPU6050?
Your code is working as expected, it tells you in setup() when it can't connect to the device, until it can.
So when it stops printing the message, it is connected.
Now in loop() you should write your code to negotiate with the device.
Here's an excellent place to start with.

Receiving all zeros in payload sent from nodemcu to Arduino UNO over UART using SerialTransfer library

I have a nodemcu master streaming sensor values to Arduino Uno slave over UART using SerialTransfer.h. I have set up an additional serial port on Arduino digital pins 2, 3 for Rx, Tx using SoftwareSerial.h. I have wired the Tx on nodemcu to Rx on Uno and Rx on nodemcu to Tx on the Uno. I have a level-shifter to adjust for 3.3 V nodemcu and 5 V Arduino. I have made sure to provide a common ground.
I transmit a struct from nodemcu with sensor values (bool and int types, hard-coded for demo) but receive only zero values at the Arduino, as seen with Serial monitor. My code is below. I'd appreciate any inputs.
I have tried the following with no difference.
With and without an extra serial port on Uno created using SoftwareSerial.h
Reversing the set up with Arduino Uno master and nodemcu slave
With and without level-shifter on nodemcu Tx and Arduino Uno Rx
Here is the code for nodemcu master.
#include <Wire.h>
#include <SerialTransfer.h>
SerialTransfer masterMCU;
struct PAYMASTER {
/*
water: instruction to switch pump on or off. Note the float sensor in pump's circuit will prevent overflow.
fan: instruction to control fan speed - LO, MED, HIGH. Note PC fan requires an int between 0 and 255.
led: instruction to control LED brightness. Note that the FastLED library requires an int between 0 and 255.
*/
bool water;
int fan;
int led;
} instructions = {
true,
201,
60
};
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
delay(999);
masterMCU.begin(Serial);
delay(999);
}
void debug() {
Serial.print("MASTER: ");
Serial.print(millis());
Serial.print(" Water: ");
Serial.print(instructions.water);
Serial.print(", Fan: ");
Serial.print(instructions.fan);
Serial.print(", LED: ");
Serial.println(instructions.led);
}
void loop() {
// put your main code here, to run repeatedly:
masterMCU.txObj(instructions, sizeof(instructions));
masterMCU.sendData(sizeof(instructions));
debug();
delay(999);
}
Here is the code for Arduino Uno slave.
#include <Wire.h>
#include <SerialTransfer.h>
#include <SoftwareSerial.h>
SerialTransfer slaveMCU;
SoftwareSerial extra(2, 3); // Rx 2, Tx 3
struct PAYMASTER {
/*
water: instruction to switch pump on or off. Note the float sensor in pump's circuit will prevent overflow.
fan: instruction to control fan speed - LO, MED, HIGH. Note PC fan requires an int between 0 and 255.
led: instruction to control LED brightness. Note that the FastLED library requires an int between 0 and 255.
*/
bool water;
int fan;
int led;
} instructions;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
delay(201);
extra.begin(9600);
delay(201);
slaveMCU.begin(extra);
delay(201);
}
void debug() {
Serial.print("SLAVE: ");
Serial.print(millis());
Serial.print(" Water: ");
Serial.print((bool)instructions.water);
Serial.print(", Fan: ");
Serial.print(instructions.fan);
Serial.print(", LED: ");
Serial.println(instructions.led);
}
void loop() {
// put your main code here, to run repeatedly:
if (slaveMCU.available()) {
slaveMCU.rxObj(instructions, sizeof(instructions));
debug();
} else if (slaveMCU.status < 0) {
Serial.print("ERROR: ");
if(slaveMCU.status == -1)
Serial.println(F("CRC_ERROR"));
else if(slaveMCU.status == -2)
Serial.println(F("PAYLOAD_ERROR"));
else if(slaveMCU.status == -3)
Serial.println(F("STOP_BYTE_ERROR"));
}
delay(999);
}
I made a few changes and data are received with correct values now.
I replaced delay() with millis() in master.
I replaced SerialTransfer::sendData() with SerialTransfer::sendDatum() in master. The former is for streaming multiple objects whereas the latter is for streaming a single object.
I replaced int types with uint8_t in the struct that is sent over wires in both master and slave.
The values are received correctly at Arduino Uno now. None of the changes made any difference until 3. above. I have retained the other changes as they also appear important to the result. Here is the final code that works for correct transmission and reception of objects from nodemcu master to Arduino Uno slave.
nodemcu master:
#include <Wire.h>
#include <SerialTransfer.h>
SerialTransfer masterMCU;
unsigned long tic = millis();
unsigned long toc = tic;
#define DELTA 1000
struct PAYMASTER {
/*
water: instruction to switch pump on or off. Note the float sensor in pump's circuit will prevent overflow.
fan: instruction to control fan speed - LO, MED, HIGH. Note PC fan requires an int between 0 and 255.
led: instruction to control LED brightness. Note that the FastLED library requires an int between 0 and 255.
*/
bool water;
uint8_t fan;
uint8_t led;
} instructions = {
true,
201,
60
};
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
delay(999);
masterMCU.begin(Serial);
delay(999);
}
void debug() {
Serial.print("MASTER: ");
Serial.print(millis());
Serial.print(" Water: ");
Serial.print(instructions.water);
Serial.print(", Fan: ");
Serial.print(instructions.fan);
Serial.print(", LED: ");
Serial.println(instructions.led);
}
void loop() {
// put your main code here, to run repeatedly:
toc = millis();
if ((toc - tic) > DELTA) {
masterMCU.txObj(instructions, sizeof(instructions));
masterMCU.sendDatum(instructions), sizeof(instructions);
debug();
tic = toc;
}
}
Arduino Uno slave:
#include <Wire.h>
#include <SerialTransfer.h>
#include <SoftwareSerial.h>
SerialTransfer slaveMCU;
SoftwareSerial Extra(2, 3); // Rx: 2, Tx: 3
unsigned long tic = millis();
unsigned long toc = tic;
struct PAYMASTER {
/*
water: instruction to switch pump on or off. Note the float sensor in pump's circuit will prevent overflow.
fan: instruction to control fan speed - LO, MED, HIGH. Note PC fan requires an int between 0 and 255.
led: instruction to control LED brightness. Note that the FastLED library requires an int between 0 and 255.
*/
bool water;
uint8_t fan;
uint8_t led;
} instructions;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
delay(201);
Extra.begin(9600);
delay(201);
slaveMCU.begin(Extra);
delay(201);
}
void debug() {
Serial.print("SLAVE: ");
Serial.print(millis());
Serial.print(" Water: ");
Serial.print((bool)instructions.water);
Serial.print(", Fan: ");
Serial.print(instructions.fan);
Serial.print(", LED: ");
Serial.println(instructions.led);
}
void loop() {
// put your main code here, to run repeatedly:
if (slaveMCU.available()) {
slaveMCU.rxObj(instructions);
debug();
} else if (slaveMCU.status < 0) {
Serial.print("ERROR: ");
if(slaveMCU.status == -1)
Serial.println(F("CRC_ERROR"));
else if(slaveMCU.status == -2)
Serial.println(F("PAYLOAD_ERROR"));
else if(slaveMCU.status == -3)
Serial.println(F("STOP_BYTE_ERROR"));
}
}

Master - Slave using SPI communication (Tinkercad)

Need your help again: I'm doing this time Master - Slave Using SPI communication, there is no error in the code when I simulate the code but the LED won't turn on.
The supposed outcome that should happen is that when I push the push button on master board the LED on the slave board will turn on.
Master code:
// Master Board
#include <SPI.h>
#define button1 4
#define SS 10
int buttonvalue;
int x;
void setup(void) {
Serial.begin(115200); //set baud rate to 115200 for usart
digitalWrite(SS, HIGH); // disable Slave Select
SPI.begin ();
SPI.setClockDivider(SPI_CLOCK_DIV8); //divide the clock by 8
}
void loop(void) {
digitalWrite(SS, LOW);
buttonvalue = digitalRead(button1);
if (buttonvalue == HIGH) {
x = 1;
} else {
x = 0;
}
digitalWrite(SS, HIGH);
delay(1000);
}
Slave code:
// Slave Board
#include <SPI.h>
#define led1 2
volatile byte Slavereceived;
volatile boolean received;
int x;
void setup(void) {
Serial.begin(115200);
pinMode(2, OUTPUT);
pinMode(MISO,OUTPUT);
SPCR |= _BV(SPE);
received = false;
SPI.attachInterrupt();
}
ISR (SPI_STC_vect) {
Slavereceived = SPDR;
received = true;
}
void loop() {
if (received) {
if (Slavereceived == 1) {
digitalWrite(led1, HIGH);
} else {
digitalWrite(led1, LOW);
}
delay(1000);
}
}
I too was stuck in the same situation, there is no support for the SPI library in tinkercad, you can include it without errors, and even use it, but any useful command will let the code stuck at that command
Sorry, but there no much you can do
this link if for a tinkercad forum, where one of the people said SPI library amoung two others are not supported
Add SPI.transfer(x); below the if else to your master code.
The master code will look somewhat like this:
// Master Board
#include <SPI.h>
#define button1 4
#define SS 10
int buttonvalue;
int x;
void setup(void) {
Serial.begin(115200); //set baud rate to 115200 for usart
digitalWrite(SS, HIGH); // disable Slave Select
SPI.begin ();
SPI.setClockDivider(SPI_CLOCK_DIV8); //divide the clock by 8
}
void loop(void) {
digitalWrite(SS, LOW);
buttonvalue = digitalRead(button1);
if (buttonvalue == HIGH) {
x = 1;
} else {
x = 0;
}
SPI.transfer(x);
digitalWrite(SS, HIGH);
delay(1000);
}

Arduino sleep while digital pin is HIGH

I want to make the Arduino Pro Mini run on a 3.7v (4.2v when fully charged) LI-Ion battery.
The project is I will use an IR sensor to control the relay. Based on the IR code received, I will toggle the relay digital output pin (HIGH or LOW). Initially, the arduino is set to deep sleep mode and when it receives an External Interrupt (pin 2 on pro-mini), it will process the IR code and switch on the relay.
//Interrupts using Arduino
//Circuit Digest
#include "LowPower.h"
#include <IRremote.h>
volatile int output = LOW;
int i = 0;
#define RECV_PIN 2
volatile boolean sleepEnabled = true;
IRrecv irrecv(RECV_PIN);
decode_results results;
void setup()
{
Serial.begin(9600);
pinMode(13, OUTPUT);
irrecv.enableIRIn();
pinMode(RECV_PIN, INPUT);
attachInterrupt(digitalPinToInterrupt(RECV_PIN), buttonPressed1, RISING); // function for creating external interrupts at pin2 on Rising (LOW to HIGH)
}
void loop()
{
Serial.println(i);
++i;
delay(1000);
output = LOW;
digitalWrite(13, output); //Turns LED ON or OFF depending upon output value
if (sleepEnabled == true) {
Serial.println("Going to sleep");
delay(1000);
LowPower.powerDown(SLEEP_FOREVER, ADC_OFF, BOD_OFF);
}
delay(500);
readIR();
}
void buttonPressed1() //ISR function excutes when push button at pinD2 is pressed
{
sleepEnabled = false;
}
void readIR() {
if (irrecv.decode(&results)) {
Serial.println(results.value, HEX);
if (results.value == 0xff4ab5) {
sleepEnabled = true;
}
}
irrecv.resume(); // Receive the next value
}
When the pro-mini goes back to sleep, everything is turned off.
How can I make the pro-mini consume minimal power while the relay pin is HIGH ?

How to control the motors via XBees wirelessly?

I am trying to control a motor wirelessly through XBee Proto Shields. The motor is controlled via an adafruit motor shield with one XBee ProtoShield stacked on top. WHat I am trying to do is, to send a signal from one protomshield connected to the computer to the one stacked on the motorshield to control it. The idea is to type '1' and that should start the motor.
The coordinator code is:
void setup() {
Serial.begin(9600);
while (!Serial);
Serial.println("Input 1 to move left, 2 to move right, 3 to move forward and 4 to move backwards");
}
void loop() {
if (Serial.available())
{
int state = Serial.parseInt();
if (state == 1)
{
Serial.println("1");
}
}}
The end device code is:`
#include <Wire.h>
#include <Adafruit_MotorShield.h>
#include "utility/Adafruit_MS_PWMServoDriver.h"
Adafruit_MotorShield AFMS = Adafruit_MotorShield();
Adafruit_DCMotor *myMotor2 = AFMS.getMotor(2);
int sentData;
void setup()
{
Serial.begin (9600);
AFMS.begin(9600);
}
void loop()
{
if (Serial.available()>0)
{
sentData=Serial.read();
if(sentData=='1'){
myMotor2->setSpeed(250);
myMotor2->run(FORWARD);
}
}
}
Instead of
if(sentData=='1')
try
if(sentData==1)

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