Damaged i2c on Rpi, switch to alternative

Hi.
I have problem with my Rpi4. Probably there is damage i2c ports. My MCP23017 chip work fine on i2c5. (pins 32 & 33)

root@zynthian:~# dtoverlay i2c5
root@zynthian:~# i2cdetect -y 5
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: 20 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

How to tell Zyntian to use i2c5 insted i2c ??

1 Like

I never tried and i’m not sure you can do it without changing a few lines of code on the zyncoder library and perhaps the wiringpi library too .

Could you describe your hardware setup? Do you have other hardware using the i2C? Most of i2s audio cards use i2c for control. Some displays also use it for the touch interface, etc.

Good luck and keep us informed about your adventures :wink:

Thx for reply. Probably I need new Rpi :frowning: BTW My screen is PiScreen 3.0, but cant find which interface it use.

I think I have an idea. Rpi has software i2c - name’s i2c-gpio. Can I use this i2c-gpio insted hardware i2c1 ?

I added a line to the /boot/config.txt file:

Uncomment some or all of these to enable the optional hardware interfaces

#dtparam=i2c_arm=on
dtparam=i2s=on
dtparam=spi=on
dtoverlay=i2c-gpio,bus=1,i2c_gpio_sda=27,i2c_gpio_scl=17

to test this solution, but the Zynthians doesn’t boot.

What is wrong ?