Rak811 Tracker Board

(Russ Nelson) #274

Hrm. Does this CPU have any non-volatile storage in it?

(Olof Ast) #275

I think it has eeprom starting at 0x08080000.
With mbed you can access it like this.

#include “mbed.h”
#include “stm32l1xx_flash.h”

FLASH_Status writeEEPROMByte(uint32_t address, uint8_t data) {
address = address + 0x08080000;
DATA_EEPROM_Unlock(); //Unprotect the EEPROM to allow writing
status = DATA_EEPROM_ProgramByte(address, data);
DATA_EEPROM_Lock(); // Reprotect the EEPROM
return status;

uint8_t readEEPROMByte(uint32_t address) {
uint8_t tmp = 0;
address = address + 0x08080000;
tmp = (__IO uint32_t)address;

return tmp;


Should be similar with cmsis,
#include “stm32l1xx_hal.h”

(Kenyu) #276

correct, any question send email to ken.yu@rakwireless.com for coordinate.

(Russ Nelson) #278

Should I expect this to work with the Tracker? https://www.aliexpress.com/item/STOTON-high-gain-SMA-connector-28dB-BEI-DOU-GPS-Antenna-Ceramic-Patch-Built-in-GPS-Active/32816386209.html?spm=a2g0s.9042311.0.0.3da24c4dFq5qNG

It seems not to work.


This one works:

Look what I found on AliExpress

(Kenyu) #280

After seriously read the discussion by this thread and rak forum, we collect the suggestion and decide to optimize the rak811 tracker design as following:

  1. The R1/C1 pin of GPS power switch chip U5 needs to be connected to a pull-up circuit。
  2. Power indicator LED1 light removed. Reserve charge indicator, and two GPIO control status indicators.
  3. The EXTINT0 and ANTON pin of the GPS module needs to be connected to GPIO to facilitate wake-up in low power mode.
  4. CP2102 chip removed, add a serial adapter board accessories。
  5. Add GPIO to detect the power supply type of the device, battery-powered or USB-powered. It can be detected using the power chip PG pin and CHG pin.
  6. Directs one UART interface for users to expand to other devices。

Any more suggestions to RAK Wireless?

(QLion) #281

Arduino Compatible ?

Thanks Kenuy!!

(Russ Nelson) #282

Yes, that does work. I have one already. I’m looking for something with a shorter cable, so it’s not so bulky.