When developing embedded systems, having the right debug probe can make all the difference. Debug probes are essential tools that connect your development PC to your target hardware, allowing you to program, debug, and analyze your embedded applications. In this post, I'll cover some of the best debug probes available today, what makes them stand out, and the scenarios where each shines.

SEGGER J-Link

What it is:

The SEGGER J-Link family is one of the most popular debug probes for ARM Cortex-M, RISC-V, and other architectures. It supports SWD, JTAG, and offers fast download speeds.

Best for:

• Professional ARM Cortex-M development
• RISC-V debugging (with newer models)
• Integration with IDEs like CodeFusion Studio, SEGGER Embedded Studio, Keil, IAR, and even open-source tools like OpenOCD

Why it's great:

• Broad device support
• Excellent performance and reliability
• Advanced features like RTT (Real Time Transfer) and SWO tracing

STMicroelectronics ST-LINK

What it is:

ST-LINK is STMicroelectronics’ in-house debug probe, bundled with many Nucleo and Discovery boards, and available as a standalone dongle.

Best for:

• STM32 microcontroller development
• Budget-conscious projects
• Use with STM32CubeIDE and STM32CubeProgrammer

Why it's great:

• Affordable or free with dev boards
• Good integration with STM32 tools
• Supports SWD and JTAG

CMSIS-DAP (DAPLink)

What it is:

CMSIS-DAP is an open standard from ARM for debug probes. DAPLink is the firmware implementation, and many low-cost boards (like the BBC micro:bit or NXP’s LPC-Link2) use it.

Best for:

• Open-source and educational projects
• ARM Cortex-M microcontrollers
• Use with pyOCD, Keil, and other CMSIS-DAP compatible tools

Why it's great:

• Open standard
• Inexpensive and widely available
• Works with many open-source tools

Black Magic Probe

What it is:

An open-source, all-in-one JTAG/SWD probe that runs GDB server firmware on the probe itself—no separate server software needed.

Best for:

• Developers who prefer open-source tools
• Direct GDB integration
• ARM Cortex-M and some RISC-V chips

Why it's great:

• Plug-and-play with GDB
• Open hardware and firmware
• Affordable

TI XDS Series

What it is:

Texas Instruments’ XDS debug probes support their MSP430, C2000, and ARM-based MCUs.

Best for:

• TI microcontroller and processor development
• Use with Code Composer Studio

Why it's great:

• Deep integration with TI tools
• Range of models from entry-level to high-end

Choosing the Right Probe

For STM32: Start with ST-LINK or J-Link.
For ARM Cortex-M (general): J-Link or CMSIS-DAP.
For open-source workflows: Black Magic Probe or CMSIS-DAP.
For TI chips: XDS series.
For RISC-V: J-Link (newer models), or some CMSIS-DAP variants.

Conclusion

The best debug probe depends on your target hardware, budget, and preferred toolchain. For most professional ARM development, J-Link is hard to beat. For STM32, ST-LINK is a great starting point. Open-source fans will love Black Magic Probe and CMSIS-DAP. Whatever you choose, a good debug probe is an investment that pays off in faster, more reliable development.

What’s your favorite debug probe? Let me know in the comments!