HAL_ADC_Start_DMA acquire only a subset of channels

Hi there,

i'm working on a STM32F103 MCU and I want to acquire 9 channels with ADC1.

With STM32Cube I configured the ADC1 in this way:

• Scan conversion mode: Enabled.
• Enable regular conversion: Enable.
• Number of conversion: 9

These is the channel list:

1. Vref Int
2. Temperature Sensor
3. IN8

4. IN9

5. IN10

6. IN11
7. IN12
8. IN13
9. IN15

Also I configured the DMA to transfer the data from the ADC to a memory buffer.

• Mode: Normal
• Increment Address: Memory
• Data Width: Word

To start the conversion I use:

HAL_ADC_Start_DMA( ADC1_ModuleHandler, ADC_1_Buffer, ADC_1_CH_MAX_VALUE )

Where:

• ADC1_ModuleHandler: ADC Handler.

• ADC_1_Buffer: uint32_t array with 9 elemets.

• ADC_1_CH_MAX_VALUE: enum to identify the channel. It starts from 0 to 9.

The conversion works fine but into the ADC_1_Buffer only the first five elements contain a value different from 0. the other 4 elements contain 0.

Moreover if I convert to analog voltage the value of the first element ( Vref Int) I obtain 1.2V that correspond to the internal Vref. So I think that the ADC conversion works.

I don't know why only a subset of channels is converted.

Do I missing some configuration parameters?

Thanks in advance!

Federico