I want to convert 4 analog input in the same time

[sunwoo lee]

Posted on March 31, 2017 at 08:04

I want to convert 4 analog input in the same time, I chose the stm32f3 303vdt because it contains 4 ADCs. The problems is that I don't know how to get them working together. I have read that only two of them can work simultaneously ADC1 and ADC2, ADC3 and ADC4.

so i can use DMA setting.

My question is what's configuration have I to do for this stuff?

Dual ADC modes

In devices with two ADCs or more, dual ADC modes can be used (see Figure 69):

• ADC1 and ADC2 can be used together in dual mode (ADC1 is master)
• ADC3 and ADC4 can be used together in dual mode (ADC3 is master)

In dual ADC mode, the start of conversion is triggered alternately or simultaneously by the ADCx master to the ADC slave, depending on the mode selected by the bits DUAL[4:0] in the ADCx_CCR register.

Four possible modes are implemented:

• Injected simultaneous mode
• Regular simultaneous mode
• Interleaved mode
• Alternate trigger mode

how can i dual adc mode?

[Tesla DeLorean]

Posted on March 31, 2017 at 08:14

Use them in pairs (ADC1+ADC2, ADC3+ADC4) in dual mode, then use a common external trigger (TIM) to synchronize them. I believe posted an example of doing this to the forum.

[Tesla DeLorean]

Posted on March 31, 2017 at 08:23

 ,

 ,

 ,

https://community.st.com/0D50X00009XkZ43SAF

 ,

https://community.st.com/0D50X00009XkZ43SAF ♯ comment-107116

 ,

[sunwoo lee]

Posted on March 31, 2017 at 08:37

i can't find ADC dualmode example.

[Tesla DeLorean]

Posted on March 31, 2017 at 08:42

I posted links but they are stuck in moderation, I dug them up using Search

 

[AvaTar]

Posted on March 31, 2017 at 10:59

I want to convert 4 analog input in the same time, I chose the stm32f3 303vdt because it contains 4 ADCs.

It would perhaps be useful to explain 'at the same time' in more detail.

Depending on the bandwidth of your input signal, a single ADC with multiplexed channels and a sufficiently high sampling rate might suffice.

I might be wrong, but the clearer the description of the issue, the less guessing.

[Dvorak.Peter]

Posted on March 31, 2017 at 15:16

It would help to know:

sample rate

input voltage range

desired resolution, accuracy

source impedance

processing requirements

sw filtering

....