Arduino for STM32

Thanks mrburnette , identifying the noise sources is in progress, but it isn't easy OK here another test with the 220 uF capacitor on 3.3v after LDO, LMT86 direct to STM32F401 ADC pa0, no Op Amp, 2000 samples, 10 samples per sec, 84 cycle sample time as is previous LMT86 to STM32401 ADC direct, 220 ...

This is a data analysis post. I used the Anderson–Darling test to test for fit to normal distribution. After removing the outliers https://en.wikipedia.org/wiki/Anderson%E2%80%93Darling_test https://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.anderson.html n = 2000, 220uf no fil 338.068...

Some findings, adding a 220 uF capacitor at the 5v supply before the LDO (it is the usb from PC actually) LMT86 to stm32f401 adc pa0 (no Op Amp) histwe220u.png count 2000.000000 mean 30.809150 std 2.734337 min 5.710000 median 30.600000 max 54.450000 Next, I set up a filter to remove all values outsi...

Next remove that Op Amp and connect the sensor LMT86 directly to the ADC (on stm32f401) 2000 samples, 10 samples/s, measuring room temperature about 30.5-31 deg C histwe2.png count 2000.000000 mean 30.930100 std 4.062343 min 3.670000 median 30.810000 max 59.260000 Next, I set up a filter to remove a...

I've been messing around with a LMT86 temperature sensor This sensor is deemed high output impedance as the documented loads it drives is 50uA. ADC noise on STM32 isn't 'new'. Just that for once I'm observing such volatility up close. The problem is mere millivolts differences means a different temp...

Get a ST-Link v2
https://www.adafruit.com/product/2548
https://www.st.com/en/development-tools/st-link-v2.html

And program it over st-link, no other 'bootloaders' are needed. In addition, with the ST-Link V2, you can debug away if you need to.

I've walked into a ditch that I seldom paid attention to, ADC noise on stm32 ADCs. The problem seemed worse on F4xx and higher devices vs STM32F103xx, This may be because of the sampling capacitance on F4 is a mere 4pf smaller than that on stm32f103 which has max 8pf spec. For once, I'm having to de...

If sample rates isn't too high say < 100 ksps, you can try using a hardware timer to drive sampling and do an analogRead(pin), what is important is to set the pin mode pinMode(pin, INPUT_ANALOG); . analogRead() may be slow, if that is the case check the ref manual for your chip and figure out how to...

You can try using an Electret_microphone on the ADC, a transistor pre-amp may be needed, u'd need to test that. The stm32 ADC has high sample rates into the 1-2 million samples per sec. So you can experiment with the sample rates easily. https://www.ncbi.nlm.nih.gov/books/NBK10924/ Humans can detect...

What is a little interesting is a large sample time 480 clocks max in the register causes more variance. This is a little counterintuitive, but it means the noise is 'digital'. e.g. switching circuits on the SOC die probably changes the voltages measured in the ADC. This is likely, as mere millivolt...