Hi all,
I have a seeed canbus shield v2.0 attached on an arduino uno.
My project is to send several data from sensors (analog/digital/i2c) from arduino to an external ECU via can bus protocol.
At the moment I have managed to connect the shield using can L & can H and declare an id10.0.0.0.1 192.168.1.254 hotmail.com
entifier as 0 (zero) running a send example from shield and I can see that there is a communication between the two devices, which is good.
Although, I cannot send the correct data.
To make it easier I have just loaded a temp/hum DHT11 sketch merged with some code lines of the shield’s send example.
Any idea how to declare and send the temperature or humidity via can bus? I have tried several combinations but still nothing.
I don’t have any experience on can bus, so any comment would be helpful.
You can find attached the code.
Thanks
[code]#include “DHT.h”
#define DHTPIN 2 // what pin we’re connected to
// Uncomment whatever type you’re using!
#define DHTTYPE DHT11 // DHT 11
//#define DHTTYPE DHT22 // DHT 22 (AM2302)
//#define DHTTYPE DHT21 // DHT 21 (AM2301)
// Connect pin 1 (on the left) of the sensor to +5V
// Connect pin 2 of the sensor to whatever your DHTPIN is
// Connect pin 4 (on the right) of the sensor to GROUND
// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor
DHT dht(DHTPIN, DHTTYPE);
#include <mcp_can.h>
#include <SPI.h>
// the cs pin of the version after v1.1 is default to D9
// v0.9b and v1.0 is default D10
const int SPI_CS_PIN = 9;
MCP_CAN CAN(SPI_CS_PIN); // Set CS pin
void setup()
{
Serial.begin(115200);
Serial.println(“DHTxx test!”);
dht.begin();
while (CAN_OK != CAN.begin(CAN_500KBPS)) // init can bus : baudrate = 500k
{
Serial.println("CAN BUS Shield init fail");
Serial.println(" Init CAN BUS Shield again");
delay(100);
}
Serial.println("CAN BUS Shield init ok!");
}
unsigned char smtp[8] = {0,1,2,3,4,5,6,7};
void loop()
{
// Reading temperature or humidity takes about 250 milliseconds!
// Sensor readings may also be up to 2 seconds ‘old’ (its a very slow sensor)
float h = dht.readHumidity();
float t = dht.readTemperature();
// check if returns are valid, if they are NaN (not a number) then something went wrong!
if (isnan(t) || isnan(h))
{
Serial.println("Failed to read from DHT");
}
else
{
Serial.print("Humidity: ");
Serial.print(h);
Serial.print(" %\t");
Serial.print("Temperature: ");
Serial.print(t);
Serial.println(" *C");
}
CAN.sendMsgBuf(0, 0, 8, smtp);
delay (10);
}[/code]
