About Christian Wächter

Christian Wächter · 2020-03-05

Hello,I'm trying to get a SPI communication in between two STM32 running with DMA. One is the STM32F051R8T7 (slave), the other ist the STM32F412ZET7 (master). There is nothing else on this SPI-bus. The best would be, if it runs with hardware controll...

Christian Wächter · 2020-02-05

Hello,I'm using a STPM32 to measure the ac line voltage and current. It is connected via a galvanic isolator ISO7341CDW to a STM32F072 with SPI. Most of the time, this works just fine. I can read the correct RMS values for I1 and V1 (Register DSP_REG...

Christian Wächter · 2019-11-25

Hello,I'm currently working on a UART communication between the mentioned STM32 microcontrollers and would like to use DMA. But I'm a bit concerned about memory consistency. I already read a lot about this issue and tried to find any information, how...

Christian Wächter · 2019-10-21

Hello,I'm trying to send some data via UART and DMA on a STM32F072, but with the low level functions. This works perfectly when using the HAL-function HAL_UART_Transmit_DMA(), but I'm missing some information for the low level functions. I configured...

Christian Wächter · 2018-07-26

I'm currently thinking about how to make the ADC-readings not neccessary as fast as possible, but to cause as little blocking as possible. My current idea is to start the reading in the main() with // Start ADC with DMA support adc_dma_values_valid ...

Christian Wächter · 2021-01-03

As I wrote, I missed to send dummy data to receive the actual data right after it has been requested. In this case, after sending the read request to the STPM32, the SPI clock will be stopped by the SPI master. When the SPI clock is enabled again (e....

Christian Wächter · 2020-04-15

> Yes. As with any wired-OR system, the value of pullup is crucial here, together with any parasitic capacitance.Well, but that's again my point from the first post: You cannot have a really fast rising edge with a pullup. That's why, the NSS pin is ...

Christian Wächter · 2020-04-14

Well, I would totally agree if hardware NSS would only work in a specific use case like descibed by you. But is the rising edge of the NSS-signal in this case a "good" edge, or the same slow charging curve like shown above?

Christian Wächter · 2020-04-14

I found my error in the meantime. I missed the sending of dummy bytes to receive the actual measurement data...

Christian Wächter · 2020-04-14

> Back your actual problem, I would just configure the NSS pin as push-pull GPIO output, and toggle the pin directly instead of playing with SPE.Well, that's what I actually did. But if you have always to do this in this way, why is the hardware NSS-...

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Get hardware NSS mode for SPI with DMA in STM32 (F0/F4) working? Or alternatively manually start the according DMA channel (Low Level functions)

Sometimes I'm reading strange values for RMS voltage and current on my STPM32, but I do not know why. Is there something very special to concider?

DMA behaviour on STM32F072 and STM32F745: Memory consistency

How to transmit USART data with DMA and low level (LL) functions?

Fastes way with as little blocking as possible to read ADC-values

Re: Sometimes I'm reading strange values for RMS voltage and current on my STPM32, but I do not know why. Is there something very special to concider?

Re: Get hardware NSS mode for SPI with DMA in STM32 (F0/F4) working? Or alternatively manually start the according DMA channel (Low Level functions)

Re: Get hardware NSS mode for SPI with DMA in STM32 (F0/F4) working? Or alternatively manually start the according DMA channel (Low Level functions)

Re: Sometimes I'm reading strange values for RMS voltage and current on my STPM32, but I do not know why. Is there something very special to concider?

Re: Get hardware NSS mode for SPI with DMA in STM32 (F0/F4) working? Or alternatively manually start the according DMA channel (Low Level functions)