Hi raiden00pl,
I just tried your recommendations, but it is still not working as it should.
I just get garbage data back from the ADC.
Eitherway, having to sample all channels sequentially is not suitable for
me. I need to select a specific channel each time.
I think I will proceed in making my own driver for the ADC.
It seems that there is a lot of work to be done on the NuttX' driver to be
usable, at least for my applications.
Στις Τρί, 15 Δεκ 2020 στις 1:57 μ.μ., ο/η raiden00pl <raiden0...@gmail.com>
έγραψε:
> I tested it on F2 (the same ADC as F4) with disabled DEBUGASSERT and it
> looks fine.
> You can try increasing the ADC_MAX_CHANNELS_NODMA value in stm32_adc.c and
> see if it works as expected.
>
> I think this assertion is only correct when we use an external trigger (eg.
> TIM trigger). In the case of software triggering data overrun should not
> occur.
>
> Note that for F4, if DMA is disabled, ADC_CR1_SCAN bit is set to 0. This
> means one trigger will start conversion on one channel.
> For a similar effect on F3 we have to set ADC_CFGR1_DISCEN=1 and
> ADC_CFGR1_DISCNUM=1, which is currently not supported.
>
>
> wt., 15 gru 2020 o 11:52 Fotis Panagiotopoulos <f.j.pa...@gmail.com>
> napisał(a):
>
> > Hi,
> >
> > this is similar to what I want to achieve. However as I see, it is only
> > supported on STM32F3's.
> >
> > On the F4's:
> > static const uint8_t g_chanlist1[];
> >
> > must have a size of 1. Else an assertion fails. So I can only configure
> one
> > pin.
> >
> > Is there any way to change this one pin to some other from my
> application?
> >
> > As I get it, throughout the whole lifetime of the firmware, from boot to
> > shutdown, only one pin can ever be used, the one declared during the
> driver
> > initialization. Correct?
> >
> >
> >
> > Στις Δευ, 14 Δεκ 2020 στις 9:05 μ.μ., ο/η raiden00pl <
> raiden0...@gmail.com
> > >
> > έγραψε:
> >
> > > Hi,
> > >
> > > I want to achieve the following sequence:
> > > > 1. Select the desired pin.
> > > > 2. Trigger a single conversion, and wait for it to finish.
> > > > 3. Read the result.
> > >
> > >
> > > This is not possible because the channel configuration cannot be
> changed
> > at
> > > runtime.
> > > But you can achieve similar functionality just by disable DMA
> conversion
> > > and use software triggers.
> > > Then each software trigger will start conversion on the next pin in the
> > > configured sequence.
> > >
> > > A simple example.
> > >
> > > You have a channel sequence set up like this:
> > >
> > > /* Identifying number of each ADC channel */
> > > >
> > > > static const uint8_t g_chanlist1[3] =
> > > > {
> > > > 9,
> > > > 15,
> > > > 8
> > > > };
> > >
> > >
> > > Then in the application you trigger the conversion (software trigger)
> and
> > > read the data from a single channel:
> > >
> > > /* Start convertion on the first configured channel (ADC
> channel
> > 9)
> > > > */
> > > >
> > > > ret = ioctl(fd, ANIOC_TRIGGER, 0);
> > > >
> > > > /* Read data from the first convertion (channel 9) */
> > > >
> > > > nbytes = read(fd, sample, sizeof(struct adc_msg_s));
> > > >
> > > > /* Start convertion on the second configured channel (ADC
> channel
> > > > 15) */
> > > >
> > > > ret = ioctl(fd, ANIOC_TRIGGER, 0);
> > > >
> > > > /* Read data from the second convertion (channel 15) */
> > > >
> > > > nbytes = read(fd, sample, sizeof(struct adc_msg_s));
> > > >
> > > > /* Start convertion on the third configured channel (ADC
> channel
> > 8)
> > > > */
> > > >
> > > > ret = ioctl(fd, ANIOC_TRIGGER, 0);
> > > >
> > > > /* Read data from the third convertion (channel 8) */
> > > >
> > > > nbytes = read(fd, sample, sizeof(struct adc_msg_s));
> > > >
> > > > /* The next trigger will start from the beginning (ADC channel
> 9)
> > > */
> > > >
> > >
> > >
> > >
> > > pon., 14 gru 2020 o 17:29 Fotis Panagiotopoulos <f.j.pa...@gmail.com>
> > > napisał(a):
> > >
> > > > Hi,
> > > >
> > > > anyone on this?
> > > >
> > > > As I see, it is impossible to set multiple channels on STM32F4xx.
> > > > To have multiple ADC channels configured for an STM32, it is required
> > to
> > > > have DMA enabled for the ADC, which seems not to be supported on
> > STM32F4.
> > > >
> > > > Is that correct? So the F4s can use only one pin in ADC?
> > > >
> > > > Στις Πέμ, 10 Δεκ 2020 στις 4:04 μ.μ., ο/η Fotis Panagiotopoulos <
> > > > f.j.pa...@gmail.com> έγραψε:
> > > >
> > > > > Hi everybody!
> > > > >
> > > > > I am trying to use the ADC on an STM32F427.
> > > > > I am able to properly register the driver and access the ADC
> device.
> > > > >
> > > > > However, I am really confused on the proper use of the driver.
> > > > > I have 8 ADC-capable pins on my board that I want to read.
> > > > >
> > > > > I want to achieve the following sequence:
> > > > > 1. Select the desired pin.
> > > > > 2. Trigger a single conversion, and wait for it to finish.
> > > > > 3. Read the result.
> > > > >
> > > > > What is the correct way to achieve this?
> > > > >
> > > >
> > >
> >
>
