X893

Turing Smart Screen 3.5"

Admin — Sat, 06 Dec 2025 09:35:00 GMT

IoT LORAWAN Nano Tracker

Admin — Tue, 17 Nov 2020 13:13:00 GMT

New nano tracker build on RAK4200 LORA module from RAK.

Module size only 18x16 mm

Contain Telit SE868 GPS module with integrated patch antenna, barometer (BMP280/BME280), light sensor (OPT3001), accelerometer (MMA8652/MMA8653), additional 4 MBytes flash for save data and firmware updates.

Activate System Bootloader on RAK4200 (STM32L071KB)

Admin — Wed, 08 Jul 2020 17:17:00 GMT

The System Bootloader in STM32L071KB (RAK4200) does a check of the BOOT0 bit and if BOOT0 is not set it checks the application at addresses 0x8010000 and 0x800000. If the stack pointer is in the SRAM range, the bootloader switches to the program in flash. Therefore, it is impossible to start the system bootloader without BOOT0 officially. But ...

1. In the application, set the flag (MAGIC number) to go to the system bootloader on reset. The address must be greater than the stack pointer of the system loader (see 0x1FF00000).

#define MAGIC_BOOT ( (uint32_t *)( 0x20003000 ) )
*MAGIC_BOOT = 0xDEADBEEF;
NVIC_SystemReset( );

2. After restart check MAGIC value and jump to system bootloader (startup_....s Keil IDE)

MAGIC_BOOT EQU 0x20003000

Reset_Handler PROC

EXPORT Reset_Handler [WEAK]

LDR R3, =MAGIC_BOOT

LDR R1, [R3, #0]

MOVS R0, #0

STR R0, [R3, #0] ; clear for next reboot

LDR R0, =0xDEADDEAD

CMP R1, R0

BNE UseNormalBoot

; Undocumented entry into the System Bootloader

LDR R0, =0x1FF00000 ; load SP SYSTEM FLASH

LDR R1, [R0, #0] ; System Boot stack

MSR MSP, R1

LDR R0, =(0x1FF00466+1) ; Jump to internal System Bootloader

BX R0 ; Now you can use ST Flash Programmer to download main flash

UseNormal

CPSIE I

LDR R0, =__initial_sp ; set stack pointer

MSR MSP, R0

LDR R0, =0xDEADBEEF ; the same value as set in application (see above)

CMP R1, R0

BNE AppStart

; start SYSTEM FLASH bootloader

LDR R4, =0x40021034 ; RCC_APB2ENR

MOVS R5, #0x1 ; enable SYSCFG/COMP clock

STR R5, [R4]

LDR R4, =0x40010000 ; SYSCFG

MOVS R5, #0x1

STR R5, [R4] ; = 01, map SYSTEM FLASH (doesn't really switch)

LDR R0, =0xDEADDEAD ; Use for undocumented entry to System Bootloader

STR R0, [R3, #0]

LDR R0, =0x1FF00000 ; load SP and PC from SYSTEM FLASH

LDR R1, [R0, #0] ; System Boot stack

MSR MSP, R1

LDR R1, [R0, #4] ; System Bootloader Reset Entry

BX R1 ; Start but really back to Reset_Handler from System Bootloader

B Reset_Handler ; really never return

IMPORT __main

IMPORT SystemInit

AppStart

LDR R0, =SystemInit

BLX R0

LDR R0, =__main

BX R0

ENDP

IoT LORAWAN Micro Tracker

Admin — Fri, 29 Jun 2018 09:50:00 GMT

New micro tracker build on RAK811 LORA module from RAK.

Module size only 24x16 mm (or 27x16 with U.FL connector)

Contain Telit SE868 GPS module with integrated patch antenna, barometer (BMP280/BME280), light sensor (OPT3001), accelerometer (MMA8652/MMA8652), additional 4 MBytes flash for save data and firmware updates.

Additional small solar panel (20x6 mm) with LTC3105 burst controller for charge battery.

Additional development board with pogo pins for debug and test (with or without RAK811 module).

BB Blue LORAWAN Gateway

Admin — Sun, 13 May 2018 12:28:00 GMT

LORAWAN gateway (with integrated GPS) on custom board and BeagleBone Blue.

Fix error in J-Link OB-STM32F072-CortexM from 26/09/2016

Admin — Mon, 06 Feb 2017 00:35:00 GMT

The latest version of firmware for the J-Link OB-STM32F072-CortexM to 26 September 2016 contains an error in the implementation of the COM transmission.

To fix you need to change a few bytes:

Address Old New

0800BD90: 90 00

0800BD91: 20 BF

0800BD92: C0 00

0800BD93: 05 BF

0800BD94: 01 00

0800BD95: 68 BF

0800BD96: 6F 00

0800BD97: 4A BF

0800BD98: 0A 00

0800BD99: 40 BF

0800BD9A: 02 00

0800BD9B: 60 BF

It may also need to connect PA7 with ground.

LORAWAN and Satellite microtrackers

Admin — Mon, 19 Sep 2016 17:05:00 GMT

New versions of microtrackers:

LORAWAN - based on iM-880A-L module
Satellite - based on STX3 module from GlobalStar

LORAWAN version (not complete).

Size:22 x 30 mm
iM880A-L MCU + SX1276
GPS module ORG1411
Accelerometer
Magnetometer
Altimeter
Flash 16MB
Solar panel charger
MicroUSB (host serial and charge)
Reed switch

Satellite version (not complete)

Size:: 22 x 30 mm (w/o antenna)
EFM32G210F128 processor
GPS module ORG1411
Accelerometer
Flash 16MB
Solar panel charger
Reed switch

LORA version has 22 x 30 x 6 mm

1 – REED switch (deep sleep/normal or other functions)

2 – GPS module with antenna ORG-1411

3 – Backup flash chip with 4-16 Mbyte

4 – microUSB for charger and to iM880A module

5 – Solar panel controller

6 – Altimeter MPL3115A2

7 – Accelerometer MMA8652

8 – Magnetometer MAG3110

8(wires) – Solar panel wires

9 – Battery wires

10 – LED (one for charger and one for custom functions)

To be continued ...

Neoway SL720 433MHz

Admin — Fri, 13 May 2016 22:28:00 GMT

Schematic for cheapest (10$) Neoway LORA module SL720.

Firmware for P2P mode

Firmware for STAR mode

LORAWAN - Second step

Admin — Wed, 16 Mar 2016 17:34:00 GMT

Prepare software development after initial hardware tests complete.

1. Cross GCC for Raspberry Pi

2. Visual Studio projects for lora_gateway/packet_forwarder (not need if prefer Eclipse)

3.Eclipse for remote debug (on RPi)

4. Visual Studo projects for TTN RESP API, TTN MQTT client and simple local UDP Server

5. Create repository and commit (https://github.com/x893/LoRaWAN)

LORAWAN - First step

Admin — Sat, 12 Mar 2016 05:56:00 GMT

Prepare LORAWAN gatewan. Build with Raspberry PI and iC880A concentrator (thanks Leeuwarden guys for module)

add some plastic details

Clone Lora-net lora-gateway and packet_forwarder (i use experimental branch), prepare configuration for TTN server and see it on map.

(this picture from iot.semtech.com site)

Now prepare node with iM880A-L module

Clone Lora-net LoRaMac-node, change SK-iM880A example ClassA node (remove POTI, LED, add UART with debug messages, etc.) and see connection to gateway and packets on server.

Create simple MQTT client to receive online messages from TTN broker (windows console application .NET).

NEXT STEP

Port gateway to LinkItOne platform (thanks Mediatek for free platform)

To be continued...