teensy_loader_cli

teensy_loader_cli --mcu=MCU [-w] [-r] [-s] [-n] [-v] *file.hex*

teensy_loader_cli is the command-line Teensy Loader from PJRC for automating firmware uploads (typically from a Makefile). Most interactive users prefer the graphical loader in Automatic Mode; this CLI is for advanced/CI workflows.You must specify the target MCU with --mcu=. Values match gcc-style chip names or logical board names such as TEENSY32, TEENSY40, TEENSY41, TEENSYLC, and others listed in the project README.On Linux, non-root access usually needs the Teensy udev rules from https://www.pjrc.com/teensy/00-teensy.rules. Building from source requires gcc and often libusb development packages (libusb-dev on Debian/Ubuntu).

--mcu=MCU

Required. Target processor or board alias (for example mk20dx256, TEENSY32, TEENSY40, imxrt1062, mkl26z64, atmega32u4).

Wait for the device to appear (HalfKay / button press). Hex is read before waiting and again after detect.

Hard reboot via a second Teensy running rebootor code (pin C7 to reset). Enables fully unattended programming.

Soft reboot request on Linux: finds a Teensy running Teensyduino USB Serial and asks it to reboot into the bootloader.

Do not reboot into the application after programming; leave HalfKay running.

Verbose status output.

Intel HEX firmware image to program.

Programming a HEX built for the wrong chip can hang USB PLL init and confuse the host USB port; recovery may need holding the reset button before connecting USB. Use matching udev rules. Graphical loader is easier for one-off flashing.

avrdude(1), dfu-util(1), openocd(1)

Source code · Homepage