ybone
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connecting a sensor to gertboard v2

Wed Jan 30, 2013 6:11 pm

hello everybody,

i want to set up a temperature sensor to the gertboard and i want to ask you if anybody has a tutorial of how to do that. the only one i found was this one: http://raspi.tv/2012/using-temperature- ... and-lm335z

but i have no idea how he connected the sensor to the gertboard via the atmega chip. it would be great if anybody could help me :)

Thank you very much

domesday
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Re: connecting a sensor to gertboard v2

Wed Jan 30, 2013 6:37 pm

I think perhaps starting with the ATMEGA micro-controller might be the wrong approach if you are a beginner.

Perhaps the easiest thing to do would be use the A/D convertor to read the value of a thermister or analogue temperature sensor.

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alexeames
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Re: connecting a sensor to gertboard v2

Wed Jan 30, 2013 7:43 pm

I'm not sure if I have records of that one, but I'll have a look :lol:
Alex Eames RasPi.TV, RasP.iO

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alexeames
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Re: connecting a sensor to gertboard v2

Wed Jan 30, 2013 8:27 pm

This was the arduino sketch. I modified the AdaFruit code to make it suit. I did have to do a fair bit of reading in the Gertboard manual to work this all out. I also wrote a short python script to process the serial input.

I'm not giving you that, as I want you to do some of the work yourself. :lol: (Tough love - sorry).

One person managed to persuade me to hand over that script and I did so on the understanding that he would keep it to himself. When he then published it on a public forum asking for help, I decided I'd learnt my lesson. If you want something to stay private, don't, errr, give it to anyone. :D

This sketch is "as is" no guarantees, but it worked for me.

Code: Select all

//TMP36 Pin Variables
int sensorPin = 0; //= PC0 on GB analog pin TMP36's Vout (sense) pin is connected to
//the resolution is 10 mV / degree centigrade with a
//500 mV offset to allow for negative temperatures
// http://learn.adafruit.com/tmp36-temperature-sensor/using-a-temp-sensor
/*
* setup() - this function runs once when you turn your Arduino on
* We initialize the serial connection with the computer
*/

void setup()
{
  Serial.begin(9600); //Start the serial connection with the computer
                      //to view the result open the serial monitor
}

void loop() // run over and over again
{
       //get digitised voltage reading from temperature sensor
  int reading = analogRead(sensorPin);
       // converting that reading to voltage, for 3.3v arduino use 3.3
  float voltage = reading * 3.3;
  voltage /= 1024.0;
       
  Serial.print(voltage); Serial.println(" volts");    // print out the voltage
       // print out temperature
  float temperatureC = (voltage - 0.5) * 100; //converting from 10 mv per degree with 500 mV offset
                                               //to degrees ((voltage - 500mV) times 100)
  Serial.print(temperatureC); Serial.println(" degrees C");
  float temperatureF = (temperatureC * 9.0 / 5.0) + 32.0;  // convert to Fahrenheight
  //Serial.print(temperatureF); Serial.println(" degrees F");
  delay(1000); //waiting a second
}
Alex Eames RasPi.TV, RasP.iO

sportsnapper
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Re: connecting a sensor to gertboard v2

Thu Jan 31, 2013 6:21 pm

Alex, try being a photographer in this digital age.... ;)

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alexeames
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Re: connecting a sensor to gertboard v2

Thu Jan 31, 2013 10:17 pm

sportsnapper wrote:Alex, try being a photographer in this digital age.... ;)
Oddly enough I considered photography as a business in 1995 before digital took over and, after looking into it thoroughly - even got to the stage of hawking some mock-ups round shops - I decided it was going to be very hard work to make any money at all. So now with everybody having a camera in their pocket the whole time, it must be a nightmare.
Alex Eames RasPi.TV, RasP.iO

ybone
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Re: connecting a sensor to gertboard v2

Fri Feb 01, 2013 5:58 am

thank you very much for all your help :) i really appreciate it!

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