Day34 - IIO I2C Multi-Channel Driver

Objective

• Implement an IIO driver over I2C
• Map multi-channel sensor data to sysfs
• Verify end-to-end data path

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Step 1 - Verify I2C Sensor

i2cdetect -y 1
i2cget -y 1 0x48 0x00

Expected:

0xa1

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Step 2 - Read Raw Registers

i2ctransfer -y 1 w1@0x48 0x10 r2
i2ctransfer -y 1 w1@0x48 0x12 r2
i2ctransfer -y 1 w1@0x48 0x14 r2

Verify:

• Values change over time
• Channel offset differences exist

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Step 3 - Load IIO Core

sudo modprobe industrialio

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Step 4 - Insert Driver

sudo insmod myadc_iio.ko
dmesg | tail -n 20

Expected:

myadc IIO device registered

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Step 5 - Check IIO Device

ls /sys/bus/iio/devices/

Expected:

iio:device0

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Step 6 - Inspect sysfs

cd /sys/bus/iio/devices/iio:device0
find . | sort

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Step 7 - Read Values

cat in_voltage0_raw
cat in_voltage1_raw
cat in_voltage2_raw
cat in_voltage_scale

Expected:

~100+n
~200+n
~300+n
0.001000

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Step 8 - Continuous Monitoring

watch -n 0.5 'cat in_voltage0_raw; cat in_voltage1_raw; cat in_voltage2_raw'

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Result

Verified:

• I2C communication
• IIO device registration
• multi-channel mapping
• dynamic data update

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