Automation, sensing and robotics • Re: dtoverlay i2c-pwm-pca9685

Status report

I enabled the I2C 0 through dtoverlay

Before configuration, pinctrl command showed the GPIO 0 and 1 is input. Now it's SDA0 and SCL0.
I searched around in overlay README and found the i2c0 section for PI5. This seems useful.
I enabled this overlay in config.txt with sudo nano and reboot pi5.
Now pinctrl is showing GPIO 0 1 configured as I2C.



/boot/overlays/README
Name: i2c0-pi5
Info: Enable i2c0 (Pi 5 only)
Load: dtoverlay=i2c0-pi5,<param>=<val>
Params: pins_0_1 Use GPIOs 0 and 1 (default)
pins_8_9 Use GPIOs 8 and 9
baudrate Set the baudrate for the interface (default
"100000")


/boot/firmware/config.txt
sudo nano /boot/firmware/config.txt
[pi5]
dtoverlay=i2c0-pi5




Before:
% pinctrl
0: a3 pu | hi // ID_SDA/GPIO0 = input
1: a3 pu | hi // ID_SCL/GPIO1 = input
2: no pu | -- // GPIO2 = none
3: no pu | -- // GPIO3 = none
4: no pu | -- // GPIO4 = none
5: no pu | -- // GPIO5 = none
6: no pu | -- // GPIO6 = none
7: no pu | -- // GPIO7 = none

After:
% pinctrl
0: a3 pu | hi // ID_SDA/GPIO0 = SDA0
1: a3 pu | hi // ID_SCL/GPIO1 = SCL0
2: no pu | -- // GPIO2 = none
3: no pu | -- // GPIO3 = none
4: no pu | -- // GPIO4 = none
5: no pu | -- // GPIO5 = none
6: no pu | -- // GPIO6 = none
7: no pu | -- // GPIO7 = none

Statistics: Posted by ifhbod30 — Sun Dec 07, 2025 9:32 pm

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