Wio-E5 (STM32 and SX1262)

[nagelc]

Hi All,
I have been messing around with a module called the Wio-E5 from Seeed Studio.
Ever since the NRF5 series came out I have wanted something similar but with a LoRa or RFM69 radio. The Wio-E5 looked like just the thing:

https://www.seeedstudio.com/LoRa-E5-Wireless-Module-Tape-Reel-p-5302.html
https://wiki.seeedstudio.com/LoRa-E5_STM32WLE5JC_Module/

Cortex-M4 processor and SX1262 radio on a chip (STM32WLE5 series)
Supposedly low power consumption (still testing).
The module is small, but hand solderable package.

I finally have one of these running as a coin cell powered temperature / humidity sensor.

My very basic E5 node and gateway

I have been able to get it to talk to my RMF95 gateway also.

If you want to give it a try, I have added code to the MySensors fork on my github: https://github.com/spike314/MySensors
in the development branch.

You will need:

• For programming STM32
  • STLink. There are cheap ones on aliexpress, but I got a legit STLink-V3MiniE for only US$11.70 on Mouser.
  • STM32Cube Programmer from https://www.st.com/
  • Arduino Libraries (available in the Arduino library manager)
    • STM32duino Low Power
    • STM32duino RTC
  • Arduino Board files
    • STM32 MCU based boards (available in the Arduino board manager)
• Updates for MySensors (already in the development branch on my github)
  • STM32 files from Pull Request 1442, from @WhiskyDelta, @Koolru, and others
  • RLSX1262 files : based on @eiten SX126X driver and:
  • RadioLib https://github.com/jgromes/RadioLib (available in the Arduino library manager). Radiolib supports the STM32WL series. So I am using it for low level code to the radio.
• Update to for AES Conflict (3/22/25 - I added a hack to my github fork that works around this issue)
  • You will get a compile error because both MySensors and STM32 define AES.
  • the offending STM32 file is here: \arduino15\packages\STMicroelectronics\hardware\stm32\2.8.1\system\Drivers\CMSIS\Device\ST\STM32WLxx\Include\stm32wle5xx.h
  • In this version, line 998: #define AES ((AES_TypeDef *) AES_BASE)
  • I changed to: #define AESWL   ((AES_TypeDef *) AES_BASE)
  • This resolves the conflict. There are probably better ways. I'd rather change the STM32 code than MySensors, but there are downsides:
    • Other files would probably need the update if you are using something besides a STM32WLE5 ....
    • If you update the STM32 library, you will have to go and change this define again.
• Clear the factory bootloader
  • ground the PB13 pin and reboot the module to get into programming mode (This step isn't needed afterall)
  • Using the STM32Cube Programmer:
    • Hit Option Bytes (OB) button. Under Read Out Protection, change to AA and hit Apply.
    • Disconnect and (re-)Connect. You should get “Data read successfully”.
• Program w Arduino
  • In your sketch, #define MY_RADIO_RLSX126x
  • Update the SX126X settings in MyConfig.h as desired, or override them in your sketch.
  • Use these board settings:
    • Board: Generic STM32WL Series
    • Board PN: Generic WLE5JCIx
    • UART Support: Enabled Generic Serial
    • Newlib Nano
    • STM31CubeProgrammer (SWD)

And, there you go!
It's all still a bit rough. I'll post some more notes and sample code when I get a chance.

Happy New Year!

[nagelc]

Quick Range Check on the WIO-E5-LE. The LE version uses only the low power PA, +14dBm max. Using the default settings except for 915MHz

#define MY_SX126x_FREQUENCY (SX126x_915MHZ)
#define MY_SX126x_LORA_SF LORA_SF7 
#define MY_SX126x_LORA_BW LORA_BW_125 
#define MY_SX126x_LORA_CR LORA_CR_4_5

I get about 190 meter range, just walking around the neighborhood, line of site except for some trees and power lines.
No tuning on the antenna. Just using a 77.9mm wire.
Not as dramatic as some have achieved with LoRa radio's, but plenty good enough for my house and yard : )