MicroPython Forum (Archive)

The STM32F407 MCUs have 5 UARTS (3 x USART and 2 X UART). I prefer the STM32F407VGT6 with 1 mb of flash on the MCU and this board has another 16M-BIT of flash on a separate IC and is under $10US https://www.aliexpress.com/item/STM32F407VET6-STM32F407VGT6-STM32-System-Board-Development-Board-F407-Si...

A Pyboard (V1.1 or D series). Whether they meet your requirement for "as cheap as possible" is moot. I would strongly recommend uasyncio rather than threading for reasons covered in the tutorial in this repo . Writing a soft UART capable of handling two concurrent 19.2Kbaud streams would be a signi...

Don't quote me on this but I think ESP32 hardware serial only has 8 bit serial There is no official soft UART implementation. The best option is probably to use hardware which does support it, such as any Pyboard. A soft UART could be written but would probably be restricted to low baud rates becau...

pythoncoder wrote: ↑

Mon Mar 18, 2019 1:14 pm

According to the docs machine.UART can read 9-bit characters so I don't see why not.

I'm using the board ttgo mini32 and it seems, that is impossible to read the 9th bit.

Is there another way to read serial in something like a RAW mode?

PM

Roberthh wrote: ↑

Mon Apr 15, 2019 8:51 am

The cut at CH340 is only needed for uploading the MicroPython firmware, right?

Yes. But if you do not get the boot message, then there is a problem with the ESP32.

I get a boot message, but it's unreadable like with a wrong baud rate.

Connect GPIO0 to GND and push the reset button. Then the ESP32 should be in bootloader mode and issue a corresponfing message. You have to go through that mode anyhow to upload the MicroPyhton firmware. This mode change is normally done through a two transistor logix on the board, controlled by the...

If you connect another USB/UART bridge to the board, pull GPIO0 low and push reset, do you get the Boot loader message at 115200 baud? And did you disable all flow control? I tried a simple USB-Serial-Adapter (Prolific) and connected it to RX, TX and Ground. What do you mean with "pull GPIO0 low"?

When you tell "Both computer (Linux and Windows) don't recognize the board - nothing.", does that mean that not /dev/ttyUSBx appears on Linux when you connect it? That is indeed strange since the CH340 worked for me on Linux always without problems. Yes... There is no new device after connecting th...

Hi, I've got today my Wemos D32 Pro board and it seems, that the CH340 doesn't work. Both computer (Linux and Windows) don't recognize the board - nothing. I tried to connect the board via GPIO1 (TX), GPIO3 (RX) and GND. After pushing reset I can see "cryptic" characters at my serial console but not...