About LLouf

LLouf · 2019-10-23

Hello,I have a problem with the bootloader on a Nucleo G071RB. I have no problem reaching the bootloader to download some new firmware in UART, after a reset and Boot0 pin set as it should, the bootloader responds to messages send through UART : when...

LLouf · 2019-10-11

Hello,Looking at the datasheet and the reference manual, I can't find the values of the hysteresis that can be used for the comparators, the datasheet simply states Low, Medium and High values, which is not very precise. Anyone knows the exact values...

LLouf · 2019-07-29

Hello,I have a small question about the bootloader, I guess this is common to all protocols but I have only tested with USART protocol. After sending the command readout unprotect, the application note states that :"After the transmission of the [fir...

LLouf · 2019-03-11

Hello,I'm testing to flash a new firmware using an ESP32 on an STM32F103xC, using the application note AN3155. There seems to be an error in the computation of the checksum that must be included in all messages. The documentation states that : 1. ...

LLouf · 2019-02-13

In my design, I have two MCUs, the STM32F103RCT6 and an ESP32. At some point, the ESP32 will perform a firmware update of the STM32. So it will need to reset it through the NRST pin, controlled through a GPIO. I have checked rapidly the datasheet, th...

LLouf · 2019-10-23

Digging a bit deeper, I've read the option bytes directly from the STM and the results seem fine : WRPArea 0x000007d2 WRPStartOffset 0x0000003f WRPEndOffset 0x00000000 RDPLevel 0x000000aa USERConfig 0x3e4ffe00 PCROPConfig 0x00000067 PCROP1AStartAdd...

LLouf · 2019-10-12

Never mind, I found it

LLouf · 2019-03-12

So after a bit of testing, I came to the following conclusion (validated by messages being acked by the STM32F103 I'm using) : the checksum for commands is simply the complement of the commandthe checksum for other payloads (addresses, data etc) is t...

LLouf · 2019-03-11

I know, for the command the wording is bit weird. But I guess the underlying mechanism is the same, except it is not accurately described. I guess a more accurate description would be "the complement of the XOR of all bytes in the message" (so if the...

LLouf · 2019-02-13

Thanks, but I know how to calculate a time constant in a RC circuit. The question that I'm asking is how much time does it need to stay low, not how much time I will need to drive the pin low.

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UART bootloader doesn't answer after successful read unprotect command

Value of the hysteresis of the comparators nowhere to be found

USART protocol in bootloader : behavior of readout unprotect

Checksum computation for UART bootloader

How long does the NRST pin has to be held low to trigger a reset (STM32F103RC) ?

Re: UART bootloader doesn't answer after successful read unprotect command

Re: Value of the hysteresis of the comparators nowhere to be found

Re: Checksum computation for UART bootloader

Re: Checksum computation for UART bootloader

Re: How long does the NRST pin has to be held low to trigger a reset (STM32F103RC) ?