Is there a tutorial for the STM32WB55 ?

[patfrench]

Hello,
Before buying a "nucleo stm32wb55"

• I would like to know if there is a tutorial to know how to use "rfcore" files ?

• I would like to know if micropython supports the capacitive touch of the stm32wb55?

Thanks

[davefes]

Are you wanting to do LoRa?

[patfrench]

Hi,
Not lora. I only need BLE (and maybe zigbee).
Thanks

[andrewleech]

I don't know of any tutorial as such, there's just a few usage notes in the files themselves. V1.13 is the latest known working version of the rfcore firmware.

I haven't used capacitive touch, don't know if it works.

[patfrench]

Thank you @andrewleech

Can I ask you a technical question?

I have a little script that sends data via the UART. I have to set the RTS line to 1 immediately after sending (I used a TXIDLE interrupt)
This script works perfectly

import machine
import time

# Fonction d'interruption appelée lorsque la transmission est terminée
def tx_complete(irq_uart):
    print("Transmission terminée. RTS = 1")
    time.sleep(0.05)
    rts.value(1)  # Remet RTS à 1 quand la transmission est finie
    

# Initialisation de l'UART et des broches
uart = machine.UART(1, baudrate=1200, tx=machine.Pin(4), rx=machine.Pin(5), parity=1)
uart.init(1200, bits=8, parity=1, stop=1)
uart.irq(handler=tx_complete, trigger=machine.UART.IRQ_TXIDLE)

rts = machine.Pin(6, machine.Pin.OUT)  # RTS en sortie

commande = bytes.fromhex("FFFFFFFFFFFFFFFFFFFF0280000082")
# Configuration de l'interruption pour détecter la fin de la transmission

while True:
    rts.value(0)  # RTS à 0 pour activer l'envoi
    # Envoi des données
    uart.write(commande)

    # Attente de réception pour tester (facultatif)
    time.sleep(0.8)
    data = uart.read(128)
    if data:
        print("Données reçues :", data)
    time.sleep(3)

I'd like to stop using an RP2 and switch to STM32 but the micropython documentation says that STM32 only supports IRQ_RXIDLE and IRQ_RX.
How would you do it ? I need to calculate my buffer send time ?

Thanks in advance

[robert-hh]

On STM32 uart.write() is not buffered. So after uart.write() all but the last byte should have been sent.

[patfrench]

Good evening Robert,

Thank you for your reply

I will try uart.flush() and/or tx.done() later this week.

I had bad results with uart.flush() on RP2 but I understand it's because of the buffer.

Is there a way to capture the flags
TXEIE and TXFNIE ?

static const machine_uart_irq_map_t mp_uart_irq_map[] = {
    { USART_CR1_IDLEIE, UART_FLAG_IDLE}, // RX idle
    { USART_CR1_PEIE,   UART_FLAG_PE},   // parity error
    #if defined(STM32G0) || defined(STM32WL)
    { USART_CR1_TXEIE_TXFNFIE, UART_FLAG_TXE}, // TX register empty
    #else
    { USART_CR1_TXEIE,  UART_FLAG_TXE},  // TX register empty
    #endif
    { USART_CR1_TCIE,   UART_FLAG_TC},   // TX complete

They are in uart.c
Thanks you

[patfrench]

😳😳😳😳😳

I just read in the source code that the flag is used here

micropython/ports/stm32/uart.c

Line 1158 in ee8d8b3

if (!uart_wait_flag_set(self, UART_FLAG_TXE, timeout)) {

micropython is really well done

[robert-hh]

uart.flush() for RP2 was changed 8 weeks ago to better match the end of transmission time. It should now wait until the data has been sent.

[patfrench]

Thank you Robert for your help

Do you know if it's possible to manipulate microcontroller registers (other than Inline assembler) ?
USART_CR2 register and the RTOIE in the USART_CR1 register for the mode MODBUS/RTU (for example)

Thank you

[robert-hh]

You can use the machine.mem32(), .mem16() and .mem8() methods for writing and reading to memory mapped registers. See https://docs.micropython.org/en/latest/library/machine.html#machine.mem32

[andrewleech]

On stm32 all the registers are directly exposed by name in the stm module: https://docs.micropython.org/en/latest/library/stm.html#peripheral-register-constants

[patfrench]

perfect !
Thank you @andrewleech and @robert-hh