About ramses946

ramses946 · 2023-07-17

Citing from the STM32L431 manual:The debug pins are in AF pull-up/pull-down after reset:• PA15: JTDI in pull-up• PA14: JTCK/SWCLK in pull-down• PA13: JTMS/SWDAT in pull-up• PB4: NJTRST in pull-up• PB3: JTDO in floating state no pull-up/pull-downLet's...

ramses946 · 2023-07-09

Hello,Following setup: STM32L431 MCU with 64 pins TQFPThe board I'm using is a minimally soldered version because I could not reach the stated figures in standby mode from the datasheet.Necessary capacitors are soldered + 1x 22uF 0805 + a 32kHz cryst...

ramses946 · 2022-11-20

Problem description:1-2 bytes in a ~30 byte message (usually at the same spot in the msg) are sometimes missing. Usually it is the 13th byte.If I send shorter msgs via SPI like 10 bytes, the other party receives them correctly.If I wait 50us after pu...

ramses946 · 2019-11-19

I have multiple boards with a STM32L051 MCU and 2 board revision, A and B.A: no LSE oscillator, LED connected via 550 Ohm resistor, around 20uF capacitance on VCC, radio module solderedB: 6pF 32kHz +-20 ppm oscillator soldered, 9pF load capacitors, a...

ramses946 · 2023-07-17

Okay, the reason I asked was that I want to use this pin to bias the gate of an external P MOSFET (switch it off during reset).So it seems that this pin can be used for this purpose even in RDP2.

ramses946 · 2023-07-09

Hi @Aime I guess you're right. I've measured both MCUs now from a batch, one measuring 580 nA, the other 590 nA. I suppose the whole batch will give figures like that.I also had the idea that maybe the 32kHz load capacitors are oversized. But measuri...

ramses946 · 2023-07-09

Without RTC the figures would be within the limits, yes.But with RTC (datasheet figures):Standby with LSE low drive: 281 nA (no max value specified)SRAM2 max consumption: 249 nAThat's 530nA in total. I'm measuring between 590 and 600 nA.

ramses946 · 2023-07-09

I've assembled another board with the same MCU.Standby with RTC in low drive mode (281 nA) + SRAM2 (173 nA) = 454 nA expectedAuto-wakeup every 2 minutes.I'm measuring 590 nA. That's more than 130 nA too much.

ramses946 · 2022-11-24

Finally I think I've found the reason why there were bytes missing.The communication was between an STM32 and a radio MCU. The command that sometimes failed was a command to fill the FIFO of the radio MCU.Probably the reason why it only worked if I t...

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STM32L4 - are pullups during reset active when RDP level is 2?

Power consumption in Standby mode a little too high

Missing bytes during SPI TX + strange MOSI line on oscilloscope

STM32L051 won't restart with LSE soldered even if using LSI

Re: STM32L4 - are pullups during reset active when RDP level is 2?

Re: Power consumption in Standby mode a little too high

Re: Power consumption in Standby mode a little too high

Re: Power consumption in Standby mode a little too high

Re: Missing bytes during SPI TX + strange MOSI line on oscilloscope