Flash the bootloader and firmware on SW102 using SWD

Please follow the next steps to be able to flash the firmware.

Table of Contents Open the SW102 and solder SWD wires Download the firmware ST-LINK driver (Windows only) Standalone flash method (Windows only) Manual flash method (Windows/Linux/MacOS) Install OpenOCD Test the electrical connection Erase/flash Done!

WARNING: There is no way to backup the original bootloader and firmware. Once you erase, booth original bootloader and firmware you will be erased forever.

Open the SW102 and solder SWD wires

There are 2 ways to open and the recommended one is by cutting a side part because in the end the SW102 will be same water resistant just like original. Also developers will be able to debug while use the keypad.

1. Open SW102 by cutting a side part and solder SWD wires
2. Open SW102 by cutting keypad base and solder SWD wires

Download the firmware

Download the latest version of the firmware from https://github.com/OpenSourceEBike/SW102_LCD_Bluetooth/releases. You will only need the `sw102-full-x.y.z.hex` file for now (the latest as of writing this line is `sw102-full-0.19.17.hex`). For any later updates you'll just use our bluetooth bootloader and update the software via your Android or iOS phone.

ST-LINK driver (Windows only)

Before connecting the ST-LINK to your machine, download the driver https://www.st.com/en/development-tools/stsw-link009.html. Scroll down to the bottom of the page to the "GET SOFTWARE" section and download "STSW-LINK009".

Standalone flash method (Windows only)

For Windows we packed a stand alone flash program. Download this zip file and unzip it somewhere on your computer. Download the latest full version hex file from https://github.com/OpenSource-EBike-firmware/SW102_LCD_Bluetooth/releases into the unzipped "SW102_First_Install_Windows" folder.
Now you can hit "start.bat" and follow the instructions on the screen!
Common error message are:

No STLink connected at all (or no drivers installed):

Connection to the SW102 wrong or bad:

If everything went well it should look like this:

Manual flash method (Windows/Linux/MacOS)

Install OpenOCD

OpenOCD is a great free tool that we will use to talk to the SW102 with the ST-LINK.

Windows: the binaries from here.

Linux: e.g. on ubuntu/debian

sudo apt install openocd

MacOS: e.g. with Homebrew

brew install open-ocd

Test the electrical connection

It's time to connect your ST-LINK, your SW102 and your machine! Your SW102 will turn on (it will take Windows a minute to install the drivers). If you have the SW102 already connected to your battery pack, make sure the battery is **OFF** while doing this installation. The power for your SW102 will come from the ST-LINK **ONLY**.

Windows:

openocd -f ..\share\openocd\scripts\interface\stlink.cfg -f ..\share\openocd\scripts\target\nrf51.cfg

Linux/MaxOS:

openocd -f $(dirname $(which openocd))/../share/openocd/scripts/interface/stlink-v2.cfg -f $(dirname $(which openocd))/../share/openocd/scripts/target/nrf51.cfg

You should then see something like this:

Open On-Chip Debugger 0.10.0
[...]
Info : STLINK v2 JTAG v29 API v2 SWIM v7 VID 0x0483 PID 0x3748
Info : using stlink api v2
Info : Target voltage: 3.242857
Info : nrf51.cpu: hardware has 4 breakpoints, 2 watchpoints

If it instead says:

Error: open failed

That means your ST-LINK is not found via USB

If it says:

Error: init mode failed (unable to connect to the target)

That means there is something wrong with the four wires from the ST-LINK to the SW-102.

After confirming OpenOCD can see your board, press ctrl-C to exit.

Erase/flash

Tip (Linux only): if trying the solderless install option, the utility `run-one-until-success` is very helpful to wrap the command and have it perpetually retry until it succeeds.

Windows:

openocd -f ..\share\openocd\scripts\interface\stlink.cfg -f ..\share\openocd\scripts\target\nrf51.cfg -c "init; reset init; nrf51 mass_erase; flash write_image sw102-full-0.19.xxx.hex; verify_image sw102-full-0.19.xxx.hex; echo FLASHED; reset halt; resume; shutdown"

Linux/MacOS:

IMG=~/Downloads/sw102-full-0.19.17.hex
openocd -f $(dirname $(which openocd))/../share/openocd/scripts/interface/stlink-v2.cfg -f $(dirname $(which openocd))/../share/openocd/scripts/target/nrf51.cfg -c "init; reset init; nrf51 mass_erase; flash write_image $IMG; verify_image $IMG; echo FLASHED; reset halt; resume; shutdown"

Example output from a successful erase/flash:

Open On-Chip Debugger 0.10.0
Licensed under GNU GPL v2
For bug reports, read
	http://openocd.org/doc/doxygen/bugs.html
Info : auto-selecting first available session transport "hla_swd". To override use 'transport select <transport>'.
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
adapter speed: 1000 kHz
Info : Unable to match requested speed 1000 kHz, using 950 kHz
Info : Unable to match requested speed 1000 kHz, using 950 kHz
Info : clock speed 950 kHz
Info : STLINK v2 JTAG v29 API v2 SWIM v7 VID 0x0483 PID 0x3748
Info : using stlink api v2
Info : Target voltage: 3.254183
Info : nrf51.cpu: hardware has 4 breakpoints, 2 watchpoints
target halted due to debug-request, current mode: Thread 
xPSR: 0xc1000000 pc: 0xfffffffe msp: 0xfffffffc
Warn : Unknown device (HWID 0x000000d6)
Info : Padding image section 0 with 2112 bytes
Info : Padding image section 1 with 32 bytes
Info : Padding image section 2 with 17680 bytes
Info : Padding image section 3 with 428 bytes
Warn : using fast async flash loader. This is currently supported
Warn : only with ST-Link and CMSIS-DAP. If you have issues, add
Warn : "set WORKAREASIZE 0" before sourcing nrf51.cfg to disable it
target halted due to breakpoint, current mode: Thread 
xPSR: 0x61000000 pc: 0x2000001e msp: 0xfffffffc
Warn : using fast async flash loader. This is currently supported
Warn : only with ST-Link and CMSIS-DAP. If you have issues, add
Warn : "set WORKAREASIZE 0" before sourcing nrf51.cfg to disable it
target halted due to breakpoint, current mode: Thread 
xPSR: 0x61000000 pc: 0x2000001e msp: 0xfffffffc
wrote 261216 bytes from file ~/Downloads/sw102-full-0.19.17.hex in 5.122993s (49.794 KiB/s)
target halted due to breakpoint, current mode: Thread 
xPSR: 0x61000000 pc: 0x2000002e msp: 0xfffffffc
target halted due to breakpoint, current mode: Thread 
xPSR: 0x61000000 pc: 0x2000002e msp: 0xfffffffc
target halted due to breakpoint, current mode: Thread 
xPSR: 0x61000000 pc: 0x2000002e msp: 0xfffffffc
target halted due to breakpoint, current mode: Thread 
xPSR: 0x61000000 pc: 0x2000002e msp: 0xfffffffc
target halted due to breakpoint, current mode: Thread 
xPSR: 0x61000000 pc: 0x2000002e msp: 0xfffffffc
verified 240964 bytes in 1.595816s (147.458 KiB/s)
FLASHED
target halted due to debug-request, current mode: Thread 
xPSR: 0xc1000000 pc: 0x000006d0 msp: 0x000007c0
shutdown command invoked

Done!

If all went well you can now see the GUI running on our device (with a simulated motor). If something doesn't work please capture any console output, and describe what happened in a bug report - we will help.