Programming lora-e5 grove board without external MCU

Products & Technology
#1

Hello,

I have one lora-e5 grove board and want to program its stm32 MCU. I can connect it to an ESP32 dev board via UART and use Arduino to program it and send data. But I want to use its own MCU without any esp32 board. To do this, I got a STLink v2 programmer and connected the board to it as follows:

photo_2022-06-27_09-12-04
photo_2022-06-27_09-12-04960×1280 225 KB

(the forum doesn’t allow me to put multiple image sin one post. The images will be in the comments)

I used the following diagram (found it over the internet but don’t remember the source):
[image 1]

When I use stm32CubeProgrammer to detect and connect the board, it fails:
[image 2]

I’m not sure even if it is possible to detect and program the lora-e5 grove using stlink or not. Maybe the board needs sth more, as I see all the people use it as the lora module with another board with external MCU.

The board is almost the same as lora-e5 mini but without mini-usb parts. Am I missing sth? How can I solve the problem?

Thank you

#2

image 1:

image
image400×568 49.5 KB

#3

image 2:

image
image1508×977 197 KB

#4

I’ve found this to be the case for me as well. I’ve had no problems programming the LoRa E5 Mini but with the E5 Grove, I’ve only managed to program it once before not being able to connect to it again with “No Stm32 device connected” error.

Make sure you have the boot pin/pad of the E5 Grove grounded as well as I believe that needs to be pulled low.

#5

I’d give this link a look: here

You’ll need to set the BOOT pin to 3.3V and the RST pin to ground. Once you press connect, you’ll need to disconnect the RST pin and that should allow the E5 Grove to connect successfully.

#6

To download and debug with STM32CubeIde also connect reset. Works like a charm. It would be even better if USART2 on pins PA2 and PA3 were connected instead PB6 and PB7. Then you could have also used the embedded serial bootloader using the connector in stead of soldering. But the hardware designer of the board fucked up big time.