The Rusty Probe
This is an open hardware probe for the Serial Wire Debug (SWD) and JTAG protocol. Based on the RP2040 MCU.
Firmware
The firmware is available here and is open-source.
Features
- The 10-pin Cortex-Debug connector is used.
- The programming connector is the Tag Connect TC2030, however for just loading firmware the USB bootloader is recommended.
- Castellated vias for all programming pins, power and 2 GPIOs.
- USB-C connector.
- Target 5V and
Vtargetis protected with an diode circuit to not have current flow from the target to the host. - The probe support 1.8v - 3.3v signal voltage and can track
Vtarget. - The key pin on the Cortex-Debug can be connected to the protected 5V.
The schematic can be found in the GitHub actions, full production files are generated for each commit.
Comparison
Here is a small comparison with a few different probes:
| Rusty Probe | PicoProbe | Raspberry Pi Debug Probe | STLinkV3 | JLink | |
|---|---|---|---|---|---|
| Max speed | 62 MHz | ? | 10 MHz | 24 MHz | 15 MHz |
| Target support | any | any | any | STM32 | any |
| IO voltage control | 1.8-3.3V | 3.3V | 3.3V | 1.6-3.3V | 1.6-3.3V sometimes |
| Type | Open Source & Hardware | Open Source | Proprietary | Proprietary | Proprietary |
| Language | Rust | C | C | C | C |
| Protocol | CMSIS-DAP | CMSIS-DAP | CMSIS-DAP | Proprietary | CMSIS-DAP |
| Programming connector | Cortex-M Debug 10p | - | JST | Cortex-M Debug 14p | Cortex-M Debug 10p |
| USB speed | 12 MBit/s | 12 MBit/s | 12 MBit/s | 480 MBit/s | 12 MBit/s |
Where to buy
The probe is available in the probe-rs shop. But you are free to build one yourself as well!
License
This work is licensed under CERN-OHL-P.