France
Asked — Edited
Resolved Resolved by Steve G!

Mpu9150 - Temperature Sensor

Hi,

I have bought the MPU9150 sensor and try to use the temperature sensor. But the sensor always displays 22 Celcius, whatever the condition...

I have followed the tutorial, and Gyro and compass seem to work just fine. I think it is just me who do not know how to use it, so any help is welcome... Thanks.


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#1  

I can report the same here. Temp stuck on 22c. Compass and gyro working.

United Kingdom
#2  

I'll throw my hat in the ring too and say I'm having the same issue. Accel, Gyro, compass are all running fine and updating no problem with the example script. But like the others, the temp stays at 22 C and does not change when exposed to subtle but different heat, even using a simple "run once" "Say("The temp is " +$TempC ) script.

United Kingdom
#3  

@fredebec and @olegodo.

Can I ask you guys, what does it say on the back of your sensors? I ask because the MPU9150, 4 in 1 sensor I ordered says this on the back...

User-inserted image

I'm curious to know why it doesn't say "Temprature" on the back as well, as it is meant to be a 4 in 1 sensor (unless I as sent the wrong one), and might go to answer why the temperature is not updating.

#4  

That is correct the MPU9150 does not do temperature if you look on the spec sheet from Sparkfun.

United Kingdom
#5  

Interesting. That's not what the store description says...

User-inserted image

confused

#6  

Yep, ez robot states it's a 4 in 1.... I guess we only get a 3 in 1?

#7  

The MPU9150 does provide temperature but I have not seen this well documented on any datasheets or from any vendors. I have an MPU9150 I got from ebay (Non-EZ-Robot) and it will provide temperature data, but I don't believe it was meant to provide room temp or weather type temp. I think of it as more like an "operating" system temp, like CPU temp sensor in a PC. In my experiments I used a heat gun to blow on the device the temperature would climb. Once the heat source was removed it slowly dropped back down.

#8  

here is the spec info on MPU9150 Features:

Tri-Axis angular rate sensor (gyro) with a sensitivity up to 131 LSBs/dps and a full-scale range of ±250, ±500, ±1000, and ±2000dps
Tri-Axis accelerometer with a programmable full scale range of ±2g, ±4g, ±8g and ±16g
Tri-axis compass with a full scale range of ±1200µT
Reduced settling effects and sensor drift by elimination of board-level cross-axis alignment errors between accelerometer, gyroscope, and compass
VDD Supply voltage range of 2.4V-3.46V; VLOGIC of 1.8V±5% or VDD
Gyro operating current: 3.6mA (full power, gyro at all rates)
Gyro + Accel operating current: 3.8mA (full power, gyro at all rates, accel at 1kHz sample rate)
Gyro + Accel + Compass + DMP operating current: 4.25mA (full power, gyro at all rates, accel at 1kHz sample rate, compass at 8Hz rate)
Accel low power mode operating current: 10uA at 1Hz, 20uA at 5Hz, 70uA at 20Hz, 140uA at 40Hz
Full Chip Idle Mode Supply Current: 8µA
400kHz Fast Mode I²C serial host interface
On-chip timing generator with ±1% frequency variation over full temperature range
10,000g shock tolerant
I2C Pullup Resistors populated on board.
All Pins Broken Out to Standard 0.1" Spaced Headers
Solder Jumper for Switching LSB of I2C Address
  

Datasheet (MPU-9150)