Spycoprobe

Spycoprobe is a USB programmer for TI MSP430FRxxxx devices. It receives commands from a host application via USB and interacts with an attached target device by bit-banging TI's Spy-Bi-Wire (SBW) protocol. The Spycoprobe firmware runs on Raspberry Pi's RP2040 microcontroller that is found on the Raspberry Pi Pico board.

Spycoprobe should work with all MSP430X devices. It has been tested with MSP430FR5994 and MSP430FR2433.

Configuring the firmware

You should replace the dummy USB vendor ID and product ID in src/usb_descriptors.c before using Spycoprobe.

You can change the pins that are used for SBW programming on top of src/main.c. There are four relevant pins:

• PIN_SBW_TCK is the SBW clock signal
• PIN_SBW_TDIO is the SBW data signal
• PIN_SBW_DIR is an optional signal specifying the direction of the SBW_TDIO signal. This can be used to switch directions of a level converter. Signal is high when data is sent from the probe to the target.
• PIN_TARGET_POWER is an optional signal to enable/disable a power supply to the target. Signal is high when programmer is active.

Building the firmware

Follow the official instructions to install and setup the Pico SDK.

Clone this repository:

git clone [email protected]:geissdoerfer/spycoprobe.git

Change to the build directory and configure cmake and build:

cd spycoprobe/firmware/build
cmake ..
make -j4

You should now find spycoprobe.hex and spycoprobe.uf2 files in the build directory.

Flashing the firmware

If you have a Raspberry Pico, disconnect it from your PC and keep pressing the BOOTSEL button while re-connecting the USB cable to your PC. A drive should appear on your PC. Copy the spycoprobe.uf2 from the build dir onto this drive. The drive should disappear, while the bootloader flashes the new firmware. A new USB CDC ACM device should appear.

Alternatively, you can use any suitable SWD debug probe to upload the hex file to the RP2040.

Usage

Attach the Spycoprobe USB connector to your PC. Connect the SBWTCK and SBWTDIO pins of Spycoprobe (GP2 and GP3 by default) and a ground wire to your target device. Make sure that the target is supplied with a similar supply voltage as the Spycoprobe (3.3V on Raspberry Pico).

Install the Python package provided under ./tools using:

cd tool
python setup.py install

Flash an image:

spycoprobe flash -i image.hex

It is planned to add support for Spycoprobe in Mspdebug, but that is still work in progress.

References

• Spycoprobe is related to Picoprobe, a Rasperry Pico based SWD debug probe
• Some inspiration for the USB protocol comes from Mspdebug and Goodfet
• The SBW routines in this project are based on TI's SLAU320AJ