# SWD In-circuit programming using a STLINK-V2 programmer

<abstract>
This article illustrates how to use the popular and cheap STLINK-V2 In-circuit SWD programmer 
with the the H10 module and Berta H10 board
</abstract>

<img src="./berta-h10-stlink-v2-ogimage.jpg">

The STLINK V2 is a very cheap Chinese SWD programmer easily available on Internet.

<img src="./stlinkv2.jpg">

This is the wiring to connect it to the Berta-H10 J2 PROG connector:

<img src="./berta-h10-stlink-v2.jpg">

| STLINK-V2 pin # |  Berta-H10 J12 pin # | Signal name |
|-----------------|----------------------|-------------|
| 2               | 9	                 | SWDIO       |
| 3	              | 8                    | GND         |
| 6	              | 7                    | SWCLK       |
| 1	              | 1                    | RESET       |

To use the STLINK V2 it is requested to install opencd on the Linux PC where is installed the 
H10 SDK by typing these commands:

	sudo apt update
	sudo apt install openocd

to launch the in-circuit type:

	make flash PROGRAMMER=openocd OPENOCD_DEBUG_ADAPTER="stlink-dap"

	...
	### Flashing Target ###
	Open On-Chip Debugger 0.11.0
	Licensed under GNU GPL v2
	For bug reports, read
		http://openocd.org/doc/doxygen/bugs.html
	dapdirect_swd
	Info : STLINK V2J29S7 (API v2) VID:PID 0483:3748
	Info : Target voltage: 3.284462
	Info : Unable to match requested speed 400 kHz, using 240 kHz
	Info : Unable to match requested speed 400 kHz, using 240 kHz
	Info : clock speed 240 kHz
	Info : stlink_dap_op_connect(connect)
	Info : SWD DPIDR 0x0bc11477
	Info : at91samd.cpu: hardware has 4 breakpoints, 2 watchpoints
	Info : at91samd.cpu: external reset detected
	Info : starting gdb server for at91samd.cpu on 0
	Info : Listening on port 36017 for gdb connections
	    TargetName         Type       Endian TapName            State       
	--  ------------------ ---------- ------ ------------------ ------------
	 0* at91samd.cpu       cortex_m   little at91samd.cpu       reset
	
	target halted due to debug-request, current mode: Thread 
	xPSR: 0x21000000 pc: 0x000010bc msp: 0x20000200
	Info : SAMD MCU: SAMR34J18 (256KB Flash, 32KB RAM)
	auto erase enabled
	wrote 49664 bytes from file /home/tanzilli/lora3a-projects/lora3a-boards/examples/sensor-node/bin/lora3a-h10/sensor-node.elf in 6.745703s (7.190 KiB/s)
	
	verified 49484 bytes in 1.075185s (44.945 KiB/s)
	
	shutdown command invoked
	Done flashing

## Links

* @article='h10_berta_getting_started'