I use Portenta H7 MCU module. I use it with a STM32CubeIDE project (not Arduino).
I do not like the Arduino IDE - LOL, I am missing several features, esp. not possible to use a HW debugger and to step through my code, no support for HW breakpoints etc. Never mind: I have a full STM32 HAL and STM32CubeIDE based project. I can use external ST-LINK (with Breakout Board).
Portenta H7 comes with an Arduino bootloader flashed: you can flash a new user BIN file (FW) via tool "dfu-util.exe".
I want to keep it, because it is convenient and no need for my users to have a ST-LINK dongle. They can update the FW any time themselves (via USB-C, needed anyway for power and UART command line).
But: I want to use also remote connections, e.g. VNC to the computer where the Portenta H7 is connected (in a lab). I cannot press the reset button quickly twice (I am remote). But I want to activate the Arduino bootloader in MCU flash so that I can update the FW (my new BIN file).
It works!
I have an UART shell command interpreter with command "bootld", implemented this way:
ECMD_DEC_Status CMD_bootld(TCMD_DEC_Results *res, EResultOut out)
{
(void)out;
(void)res;
RTC->BKP0R = 0x0000DF59;
RTC->BKP7R = 0x00000001;
NVIC_SystemReset();
return CMD_DEC_OK;
}
So, it uses the "trick" to write "magic" values into RTC BKP registers. When I fire a reset (here via SW as NVIC_SystemReset();) - the Arduino bootloader sees the magic value and stays in DFU mode (not jumping to my FW entry point as any regular (single) reset button would do). Now I can flash a new FW via "dft-util.exe".
Just:
It takes approx. 10 seconds until I see the fading flashing green LED (as indication that Arduino bootloader is active and in DFU mode). No idea why 10 sec.: a double reset press is way faster (but I cannot do remotely).
If you want to try my project - or you want to use STM32CubeIDE to develop for Portenta H7 (as I do), here is the project:
https://github.com/tjaekel/PortentaH7_WAcouSense
It is a pretty "heavy" project, mainly with these features:
- it provides an USB VCP port to have an UART Shell Command line
- with a Breakout Board (or Vision Shield) it provides PDM MICs, streamed via ETH and VBAN to a host PC,
also with a web page in MCU (control MCU from Web Browser instead or in parallel with UART VCP COM) - with Breakout Board: an I2C based 9-DOF sensor connected (e.g. for gestures)
- a "Pico-C" C-code interpreter: write C-code on MCU without any compiler, use SD Card to store "Pico-C" C-code scripts and execute these from UART command line
If you do not want to install the entire project and compile:
- you can grab the BIN file in GitHub bin folder
- plus the "dfu-util.exe"
- and flash Portenta H7 via Windows CMD line (see Readme in bin folder)
BTW: via Pico-C you can write C-code scripts for any I2C device connected (there is an example for the IMU sensor, in folder doc). Also SPI is available on the command line: connect SPI devices and write "PIco-C" code (no need for any compiler or to flash FW again).
