What hardware is inside the Wio-E5 / LoRa-E5

Products & Technology
#1

Hello, I am designing a product which includes a Wio-E5 (aka LoRa-E5) module.
In order to write the firmware on it, I need to know some details which are hard to find:

  1. What is the exact partnumber of the STM32WLE inside this module. This is needed so in STM32CubeMx we can create the correct projects.

  2. Does the module provide an external 32,768 kHz XTAL to the MCU, so we can run the RealTimeClock from that source ?

  3. Is the MCU VBAT connected to VDD, so when we power the module with a battery, we can measure the battery voltage through ADC-VBAT

Thank you

#2

One more question : can you clarify something about the pin 24 : PB13
The datasheet mentions this pin as SPI2-CLK, which matches with the SMT32WLE datasheet, but it also mentions Boot pin (active low)
At first I thought this was the BOOT0 pin, to force the MCU into bootloader, but there are 2 strange things:

  1. the BOOT0 pin is PH3 on the STM32WLE (not PB13).
  2. to force bootloader, you need to bring the BOOT0 pin HIGH, not LOW.

So I need a bit more info about how this pin is working internally in the LoRa-E5 module

On the LoRa-E5 development board, the USB-SERIAL is connected to PB6/PB7 of UART1, which cannot be used for bootloading (STM32WLE can bootload from UART1 on pins PA9/PA10 or from UART2 on pins PA2/PA3).

So what does this BOOT button (pulling PB13 low) do ?

#3

Hi, the model number of this MCU is STM32WLE5JC, I am confirming the other issues you mentioned, you can check the schematic first to confirm

#4

Thank you.
I have studied the schematics of the development boards

but this can not answer my questions above. If there is a schematic of the internals of the Wio-E5 module, please point me to it, as I could not find that. (I assume this will not be disclosed to end users…)

#5

In the mean time, these questions are somehow answered by experiments:

  • part number seems to work fine in Stm32Cube
  • 32.768 kHz LSE seems to drive the RTC just fine
  • question about vBat is no longer relevant. You need to measure the Vdd voltage through vRefInt.

Question about bootloading over serial remains.

P

#6

Hello, kind reminder : can you clarify what is the function of the PB13 pin (named BOOT0) ?