Hello, I am using the Zephyr operating system with the STM32U5G9J-DK2 hardware. I intend to collect voltage data using the ADC, but so far, no progress has been made. Here are the steps I have taken:
-
I used the zephyr\samples\drivers\adc\adc_sequence example from Zephyr 4.2.0.
-
I created a new app.overlay file in the root Vmakelists.txt directory with the following content:
/ {
aliases {
adc0 = &adc1;
};
};
&vbat1 {
status = "okay";
io-channels = < &adc1 5 >;
};
-
I compiled using this command:west build -p always -b stm32u5g9j_dk2 --sysbuild .
-
Then I supplied 1V to the PA0 pin (silkscreen labeled PWM/D6), and the log is as follows:
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[16:22:28.487] RX←◆*** Booting Zephyr OS build v4.2.0 ***ADC sequence reading [0]:
[16:22:29.493] RX←◆- adc@42028000, channel 5, 5 sequence samples:
2684 = 2162mV
1788 = 1440mV
1571 = 1265mV
1532 = 1234mV
1492 = 1202mV
adc@42028000, channel 12, 5 sequence samples:
2092 = 1685mV
1660 = 1337mV
1571 = 1265mV
1532 = 1234mV
1532 = 1234mV
-
Subsequently, I changed the supply voltage to 2V, and the log is as follows:[16:27:39.509] RX←◆- adc@42028000, channel 5, 5 sequence samples:
0 = 0mV
1068 = 860mV
1404 = 1131mV
1492 = 1202mV
1492 = 1202mV
adc@42028000, channel 12, 5 sequence samples:
636 = 512mV
1315 = 1059mV
1492 = 1202mV
1492 = 1202mV
1532 = 1234mV
No significant changes are observable. I also tried the example in samples\boards\st\power_mgmt\adc\src\main.c, but still cannot obtain correct results. Could you please advise on how to acquire accurate ADC values using Zephyr?
