Hello,has anyone used a high temp thermocouple amp like the MAX 31855k with a RaspberryPi MQTT? I was looking for code examples to put one together for a Grill smoker temp probe.
Fist, connect you with raspberry pi and get the sensor value Overview | MAX31855 Thermocouple Sensor Python Library | Adafruit Learning System. Once you have succesfully got the sensorr value, add a device to cayenne using cayenne MQTT python library GitHub - myDevicesIoT/Cayenne-MQTT-Python: Python Library for Cayenne MQTT API. then combine got the codes and send the sensor value to cayenne,
Ok, I’ve been unable to get the Adafruit code to work in the past but have been able to get this one to work GitHub - Tuckie/max31855: Raspberry Pi driver for MAX31855 Cold-Junction Compensated Thermocouple-to-Digital Converter do you think this one would work with Cayenne?
Yes, that can work. just publish the sensor value from the above code to cayenne.
Ok, so I would need to get the sensor value from the shell to Cayenne?
yes using this Cayenne-MQTT-Python/Example-01-SendData.py at master · myDevicesIoT/Cayenne-MQTT-Python · GitHub
Ok,Thanks. I was thinking would it be best to use something like a Arduino Yun were you would’nt have to worry about powering it down since it would be unplugged and moved often. Ive been looking through code and found the Cayenne-Connections- Yun code.
// This example shows how to connect to Cayenne using an Arduino Yun and send/receive sample data.
//#define CAYENNE_DEBUG
#define CAYENNE_PRINT Serial
#include <CayenneMQTTYun.h>
// Cayenne authentication info. This should be obtained from the Cayenne Dashboard.
char username[] = "MQTT_USERNAME";
char password[] = "MQTT_PASSWORD";
char clientID[] = "CLIENT_ID";
unsigned long lastMillis = 0;
void setup() {
Serial.begin(9600);
Cayenne.begin(username, password, clientID);
}
void loop() {
Cayenne.loop();
//Publish data every 10 seconds (10000 milliseconds). Change this value to publish at a different interval.
if (millis() - lastMillis > 10000) {
lastMillis = millis();
//Write data to Cayenne here. This example just sends the current uptime in milliseconds.
Cayenne.virtualWrite(0, lastMillis);
//Some examples of other functions you can use to send data.
//Cayenne.celsiusWrite(1, 22.0);
//Cayenne.luxWrite(2, 700);
//Cayenne.virtualWrite(3, 50, TYPE_PROXIMITY, UNIT_CENTIMETER);
}
}
//Default function for processing actuator commands from the Cayenne Dashboard.
//You can also use functions for specific channels, e.g CAYENNE_IN(1) for channel 1 commands.
CAYENNE_IN_DEFAULT()
{
CAYENNE_LOG("CAYENNE_IN_DEFAULT(%u) - %s, %s", request.channel, getValue.getId(), getValue.asString());
//Process message here. If there is an error set an error message using getValue.setError(), e.g getValue.setError("Error message")
I was wondering if there’s away to clean up and combine theses codes? I’m new to Arduino code and I’m not sure how to make this work.
/***************************************************
This is an example for the Adafruit Thermocouple Sensor w/MAX31855K
Designed specifically to work with the Adafruit Thermocouple Sensor
----> https://www.adafruit.com/products/269
These displays use SPI to communicate, 3 pins are required to
interface
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
Written by Limor Fried/Ladyada for Adafruit Industries.
BSD license, all text above must be included in any redistribution
****************************************************/
#include <SPI.h>
#include "Adafruit_MAX31855.h"
// Default connection is using software SPI, but comment and uncomment one of
// the two examples below to switch between software SPI and hardware SPI:
// Example creating a thermocouple instance with software SPI on any three
// digital IO pins.
#define MAXDO 3
#define MAXCS 4
#define MAXCLK 5
// initialize the Thermocouple
Adafruit_MAX31855 thermocouple(MAXCLK, MAXCS, MAXDO);
// Example creating a thermocouple instance with hardware SPI
// on a given CS pin.
//#define MAXCS 10
//Adafruit_MAX31855 thermocouple(MAXCS);
void setup() {
while (!Serial); // wait for Serial on Leonardo/Zero, etc
Serial.begin(9600);
Serial.println("MAX31855 test");
// wait for MAX chip to stabilize
delay(500);
}
void loop() {
// basic readout test, just print the current temp
Serial.print("Internal Temp = ");
Serial.println(thermocouple.readInternal());
double c = thermocouple.readCelsius();
if (isnan(c)) {
Serial.println("Something wrong with thermocouple!");
} else {
Serial.print("C = ");
Serial.println(c);
}
//Serial.print("F = ");
//Serial.println(thermocouple.readFarenheit());
delay(1000);
}
Thanks.
is this a separate topic? your issue with pi has been solved?
Hello, sorry the last post should have been a separate topic, I’m still working with the RaspberryPi part.
regarding the Yun topic you need to send double c = thermocouple.readCelsius(); to cayenne using:
if (millis() - lastMillis > 10000) {
lastMillis = millis();
Cayenne.virtualWrite(1, c, "analog_sensor", "null");
}
Ok, so I would need to put the max31855 code and the Cayenne code together and flash it to the Yun correct?
yes and send the sensor value using above code.
Hello, I think I got it, something like this?
// This example shows how to connect to Cayenne using an Arduino Yun and send/receive sample data.
//#define CAYENNE_DEBUG
#define CAYENNE_PRINT Serial
#include <CayenneMQTTYun.h>
#include <SPI.h>
#include "Adafruit_MAX31855.h"
// Default connection is using software SPI, but comment and uncomment one of
// the two examples below to switch between software SPI and hardware SPI:
// Example creating a thermocouple instance with software SPI on any three
// digital IO pins.
#define MAXDO 3
#define MAXCS 4
#define MAXCLK 5
// initialize the Thermocouple
Adafruit_MAX31855 thermocouple(MAXCLK, MAXCS, MAXDO);
// Example creating a thermocouple instance with hardware SPI
// on a given CS pin.
//#define MAXCS 10
//Adafruit_MAX31855 thermocouple(MAXCS);
// Cayenne authentication info. This should be obtained from the Cayenne Dashboard.
char username[] = "MQTT_USERNAME";
char password[] = "MQTT_PASSWORD";
char clientID[] = "CLIENT_ID";
unsigned long lastMillis = 0;
void setup() {
while (!Serial); // wait for Serial on Leonardo/Zero, etc
Serial.begin(9600);
Serial.println("MAX31855 test");
// wait for MAX chip to stabilize
delay(500);
Cayenne.begin(username, password, clientID);
}
void loop() {
Cayenne.loop();
// basic readout test, just print the current temp
Serial.print("Internal Temp = ");
Serial.println(thermocouple.readInternal());
double c = thermocouple.readCelsius();
if (isnan(c)) {
Serial.println("Something wrong with thermocouple!");
} else {
//Serial.print("C = ");
//Serial.println(c);
}
Serial.print("F = ");
Serial.println(thermocouple.readFarenheit());
delay(1000);
//Publish data every 10 seconds (10000 milliseconds). Change this value to publish at a different interval.
if (millis() - lastMillis > 10000) {
lastMillis = millis();
//Write data to Cayenne here. This example just sends the current uptime in milliseconds.
Cayenne.virtualWrite(1, c, "analog_sensor", "null");
}
//Some examples of other functions you can use to send data.
//Cayenne.celsiusWrite(1, 22.0);
//Cayenne.luxWrite(2, 700);
//Cayenne.virtualWrite(3, 50, TYPE_PROXIMITY, UNIT_CENTIMETER);
}
//Default function for processing actuator commands from the Cayenne Dashboard.
//You can also use functions for specific channels, e.g CAYENNE_IN(1) for channel 1 commands.
CAYENNE_IN_DEFAULT()
{
CAYENNE_LOG("CAYENNE_IN_DEFAULT(%u) - %s, %s", request.channel, getValue.getId(), getValue.asString());
//Process message here. If there is an error set an error message using getValue.setError(), e.g getValue.setError("Error message");
}
Thanks,Adam.
yes that should work. try removing delay(1000); from main loop.
Ok thanks, would I need to change double c = thermocouple.readCelsius(); to make this read and send the data in Fahrenheit?
double F = thermocouple.readFarenheit();
Cayenne.virtualWrite(2, F, "temp", "f");
and also you need to change:
Cayenne.virtualWrite(1, c, "analog_sensor", "null");
to
Cayenne.virtualWrite(1, c, "temp", "c");
`
ok, something like this?
// This example shows how to connect to Cayenne using an Arduino Yun and send/receive sample data.
//#define CAYENNE_DEBUG
#define CAYENNE_PRINT Serial
#include <CayenneMQTTYun.h>
#include <SPI.h>
#include "Adafruit_MAX31855.h"
// Default connection is using software SPI, but comment and uncomment one of
// the two examples below to switch between software SPI and hardware SPI:
// Example creating a thermocouple instance with software SPI on any three
// digital IO pins.
#define MAXDO 3
#define MAXCS 10
#define MAXCLK 5
// initialize the Thermocouple
Adafruit_MAX31855 thermocouple(MAXCLK, MAXCS, MAXDO);
// Example creating a thermocouple instance with hardware SPI
// on a given CS pin.
//#define MAXCS 10
//Adafruit_MAX31855 thermocouple(MAXCS);
// Cayenne authentication info. This should be obtained from the Cayenne Dashboard.
char username[] = "*************************";
char password[] = "****************************";
char clientID[] = "********************************";
unsigned long lastMillis = 0;
void setup() {
Serial.begin(9600);
Cayenne.begin(username, password, clientID);
//while (!Serial); // wait for Serial on Leonardo/Zero, etc
//Serial.println("MAX31855 test");
// wait for MAX chip to stabilize
delay(500);
}
void loop() {
Cayenne.loop();
// basic readout test, just print the current temp
//Serial.print("Internal Temp = ");
//Serial.println(thermocouple.readInternal())
double F = thermocouple.readFarenheit();
//Publish data every 10 seconds (10000 milliseconds). Change this value to publish at a different interval.
if (millis() - lastMillis > 10000) {
lastMillis = millis();
//Write data to Cayenne here. This example just sends the current uptime in milliseconds.
Cayenne.virtualWrite(2, F, "temp", "f");
}
//Some examples of other functions you can use to send data.
//Cayenne.celsiusWrite(1, 22.0);
//Cayenne.luxWrite(2, 700);
//Cayenne.virtualWrite(3, 50, TYPE_PROXIMITY, UNIT_CENTIMETER);
}
//Default function for processing actuator commands from the Cayenne Dashboard.
//You can also use functions for specific channels, e.g CAYENNE_IN(1) for channel 1 commands.
CAYENNE_IN_DEFAULT()
{
CAYENNE_LOG("CAYENNE_IN_DEFAULT(%u) - %s, %s", request.channel, getValue.getId(), getValue.asString());
//Process message here. If there is an error set an error message using getValue.setError(), e.g getValue.setError("Error message");
}
yes that will work.
Ok, thanks. On the RaspberryPi side the code would have to be combined with the Max31855 code and saved on the Pi in a file?
Yes you have to save it with .py extension and run it.