STW TC1, User Manual

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10 Application Notes
User Manual 318/374
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10.1.5 I/O Pin's
The TC1 comes with 1 digital output and 1 digital input.
Digital Output:
This output is designed to provide power to an attached device, e.g. an external GPS receiver with up to 400
mA at DC 12 V. It is equipped with an internal 10 kOhm pull down resistor. To prevent damage to the TC1, an
external fuse must be applied to make sure the current does not exceed 400 mA.
The output can be switched ON / OFF over the driver interface with the following command:
echo 1 > /proc/stw_io/PIN1 //To turn ON the output use command:
echo 0 > /proc/stw_io/PIN1 //To turn OFF the output use command:
cat /proc/stw_io/PIN1 //To read back this output:
Digital Input:
This digital input has a built in 10kOhm pull down resistor and a threshold Voltage of ~3.5V. Signals below this
Voltage will result in "0", signals above this Voltage will result in "1".
This input can be queried through the driver interface with the command:
/proc/stw_io/Pin2 //e.g.: "cat /proc/stw_io/Pin2"