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Topic: Did you know: the Arduino GSM shield also has a thermperature sensor? (Read 1 time) previous topic - next topic

MathiasVDA

Dec 23, 2013, 08:39 pm Last Edit: Dec 24, 2013, 11:36 pm by MathiasVDA Reason: 1
To activate the thermometer, first send the AT command: AT+QTEMP=1
To read the current temperature, send the AT command: AT+QTEMP?

How to send AT commands:
http://forum.arduino.cc/index.php?topic=206159.0

Code: [Select]
Connecting to GSM network...
Connected to GSM, now GPRS...
GSM shield fully connected.

Sending command: AT+QTEMP=1

OK

Sending command: AT+QTEMP?

+QTEMP: 1,22

OK

robtillaart

interesting find, some questions pop up:
- Celsius, Fahrenheit,
- how accurate?
- Does it measure temperature of the GSM chip (overheating calls ;)  or the environment?
Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)

MathiasVDA

Hey robtillaart.  the documentation is not very accurate but here is what I think:

- definitely Celsius,
- how accurate? --> well, it's rounded to 1 °C
- Does it measure temperature of the GSM chip (overheating calls smiley-wink  or the environment? --> no idea, I get a pretty constant value all the time but I'm not doing anything major with the GSM board. I'll check again when I do some uploads

What I forgot to mention in my first post is that the response from the board:
+QTEMP: 1,22

<mode>,<voltage>,<temperature> is from the documentation. I don't know why there are only 2 parameters but since the current ambient temperature is 21°, the second parameter is probably <temperature>. If you send the command
Code: [Select]
AT+QTEMP=? then you get:
Sending command: AT+QTEMP=?

+QTEMP:<mode>(0,1),<Temperature>(-40 - 90))


Also form documentation:
<Mode> = 1 if enabled.
<voltage> The current voltage of the temperature sensitive resistor(mV)
<temperature> The current temperature of the temperature sensitive resistor
Range is from -40 to 90(?)

I'm using the GSM shield for data upload from a remote (outside) location. I already measure the ambient temperature outside my box but I thought of using this sensor values for inside box temperature measurement (nice to have but not necessairy).

robtillaart

Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)


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