This is an open hardware probe for the Serial Wire Debug (SWD) and JTAG protocol. Based on the RP2040 MCU.
The firmware is available here and is open-source.
- 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.
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 interface support | JTAG, SWD, SWO, UART | SWD | SWD, UART | JTAG, SWD, UART, SWO Note: STM8/32 chips only |
JTAG, SWD, SWO |
| IO voltage control | 1.8-3.3V | 3.3V | 3.3V | 1.6-3.3V | 1.6-3.3V somtimes |
| 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 |
The probe is available in the probe-rs shop. But you are free to build one yourself as well!
This work is licensed under CERN-OHL-P.