I2C on Sweet Potato

Software
1

I acquired a Sweet Potato a few days ago and am generally delighted with it. Congrats, Libre folks!

Although I did not intend this board as an IoT end node, I tried to test I2C with a BME280, but only /dev/i2c-0 is exposed and cannot find i2c-1 or 2.

Similarly, I tried a test with a DHT22 connected to Pin 7 and came up empty again.

Anybody had success with either of these?

2

Folks. With the help of a Reddit user and from Gemini AI, I have I2C working on the Sweetie. I will try to recall everything I did to get it going. Here:
wget https://deb.libre.computer/repo/pool/main/libr/libretech-keyring/libretech-keyring_2024.05.19_all.deb
dpkg -i libretech-keyring_2024.05.19_all.deb
apt update
apt upgrade
ldto reset
ldto enable i2c-ao
ls -al /dev/i2c-*
ls -al /dev/i2c-*

crw-rw---- 1 root i2c 89, 0 Jan 11 16:18 /dev/i2c-0

crw-rw---- 1 root i2c 89, 1 Jan 12 21:12 /dev/i2c-1
Then I connected the BME280 and reran:
ls -al /dev/i2c-*
crw-rw---- 1 root i2c 89, 0 Jan 13 12:22 /dev/i2c-0
root@oncilla:~# # Temporarily enable it again
sudo ldto enable i2c-ao

Now, make it survive the next reboot

sudo ldto merge i2c-ao
Overlay i2c-ao: applied
Overlay i2c-ao: merged for next boot
root@oncilla:~# ls -al /dev/i2c-*
crw-rw---- 1 root i2c 89, 0 Jan 13 12:22 /dev/i2c-0
crw-rw---- 1 root i2c 89, 1 Jan 13 12:33 /dev/i2c-1
root@oncilla:~# i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – – – – – – – –
10: – – – – – – – – – – – – – – – –
20: – – – – – – – – – – – – – – – –
30: – – – – – – – – – – – – – – – –
40: – – – – – – – – – – – – – – – –
50: – – – – – – – – – – – – – – – –
60: – – – – – – – – – – – – – – – –
70: – – – – – – 76 –
and a little Python test script gave:
2026-01-13 17:39:34, 19.20C, 984.43hPa, 49.00%
2026-01-13 17:39:36, 20.17C, 985.86hPa, 49.02%

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