# Enabling I2C Bus

**URL:** <https://community.zymbit.com/t/enabling-i2c-bus/1204>\
**Category:** HSM4\
**Created:** [June 25, 2021, 12:53am UTC](https://community.zymbit.com/t/enabling-i2c-bus/1204 "2021-06-25T00:53:56Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![secure](https://avatars.discourse-cdn.com/v4/letter/s/edb3f5/32.png) [@secure](https://community.zymbit.com/u/secure)\
**Post date:** [June 25, 2021, 12:53am UTC](https://community.zymbit.com/t/enabling-i2c-bus/1204/1 "2021-06-25T00:53:57Z")

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I am trying to automate some of the installation process. I thought I could change the file /boot/config.txt to uncomment the # in front of dtparam=i2c\_arm=on and this would work. However … neither the HSM4 nor the Zymkey “bind” (turn from blinking rapidly to once every three seconds) until I manually open the raspberry pi config from the terminal and enable the I2C bus that way. Does anyone know why this is? And if I can avoid it?

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**Author:** ![Bob\_of\_Zymbit](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@Bob\_of\_Zymbit](https://community.zymbit.com/u/Bob_of_Zymbit)\
**Post date:** [June 26, 2021, 12:52am UTC](https://community.zymbit.com/t/enabling-i2c-bus/1204/2 "2021-06-26T00:52:28Z")

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You will also need to tell the kernel to load the i2c-dev module. Edit /etc/modules  
and add the line `i2c-dev`. Reboot and use `ls -l /dev/i2c*` to verify that the i2c bus now exists.