On 26/04/2021 19:25, Ed Lee wrote:
> Does anyone know how to do it in register level?
>
> I see many code examples using:
>
> ADC_ChannelConfTypeDef sConfig = {ADC_CHANNEL_0, 1, ADC_SAMPLETIME_28CYCLES};
> HAL_ADC_ConfigChannel(&hadc1, &sConfig);
> or
> ADC_RegularChannelConfig(ADC1, ADC_channel_0, 1, ADC_SampleTime_480Cycles);
>
> but i don't have access to these routines from arm-gcc.
>

That last statement shows you perhaps don't have a full understanding of
what you are doing here.

However, the most likely cause of your troubles is that the examples you
have are using an SDK from ST, and you either don't have the SDK
installed and set up correctly, or you aren't using it in your project,
or you have simply forgotten to include the appropriate headers at the
start of your C file.

I have not used ST's tools myself, but I would expect that their SDK
comes with complete working example projects for some evaluation boards.
Start with one of these, and adapt it to suit your required changes.

> By the way, i am using this to read the adc data:
>
> #include "stm32f407xx.h"
> ADC1->CR2 |= ADC_CR2_SWSTART; // Start A2D
> while (!(ADC1->SR & ADC_SR_EOC)); // ready wait
> data = ADC1->DR;
>