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Temperature Sensor (Linux)

 

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NVIDIA Tegra based modules

The temperature sensor is able to report the PCB's temperature as temp1 and the NVIDIA Tegra T20/T30 chip's internal temperature as temp2. The output is provided in 1000ths of degrees Celsius (Colibri T20 V1.x BSPs provided it in degrees Celsius). Therefore it must be divided by 1000 to obtain degrees.

root@colibri_t20:~# cat /sys/bus/i2c/devices/4-004c/temp1_input
29625
root@colibri_t20:~# cat /sys/bus/i2c/devices/4-004c/temp2_input
31125
root@colibri-t30:~# cat /sys/bus/i2c/devices/4-004c/temp1_input
52468
root@colibri-t30:~# cat /sys/bus/i2c/devices/4-004c/temp2_input
45625

NXP/Freescale iMX6 based modules

The iMX6 provides a temperature reading of the SoC's internal temperature plus the board temperature is available via ADC/touch chip albeit with a much lesser accuracy. The output is in 1000ths of degrees Celsius. Therefore it must be divided by 1000 to obtain degrees.

root@colibri-imx6:~# cat /sys/devices/virtual/thermal/thermal_zone0/temp
54325
root@colibri-imx6:~# cat /sys/bus/iio/devices/iio\:device0/in_temp8_raw
35318

NXP/Freescale Vybrid based modules

The Vybrid's internal temperature sensor is connected internally to its ADC module's analogue input channel, the readout of temperature is given by in_temp_input. The output is in 1000ths of degrees Celsius. Therefore it must be divided by 1000 to obtain degrees.

root@colibri-vf:~# cat /sys/bus/iio/devices/iio:device1/in_temp_input
40760