Unbrick

Have you tried updating the bootloader of Buzzpirat or Bus Pirate v3 and it doesn’t work? Doesn’t it even enter bootloader mode when bridging the PGD and PGC pins? Don’t worry, there are several ways to fix it.

Unbrick using a Raspberry Pi Pico (bp3unbricker)

bp3unbricker turns a Raspberry Pi Pico or Pico 2 into a programmer for the Bus Pirate v3. One press of its BOOTSEL button writes bootloader v4.5 and Community Firmware v7.1.12 (BPCOMPBZ), then reads everything back to check it. No PICkit, MPLAB or drivers needed.

Total cost: ~6$

• Buy a Raspberry Pi Pico (RP2040) or Pico 2 (RP2350)
• Buy 4 dupont cables FEMALE-FEMALE
• Two USB cables: one for the Pico, one for the bricked device

Connect the pins in the following manner. On a Buzzpirat, use the pins with the same names:

1. Download bp3unbricker-pico.uf2 (Pico) or bp3unbricker-pico2.uf2 (Pico 2) from this page:
   • https://github.com/therealdreg/bp3unbricker/releases/latest
2. Hold the Pico’s BOOTSEL button while you plug it into the PC, then release it. Copy the .uf2 file to the drive that appears (RPI-RP2 or RP2350).
3. Wire the Pico to the bricked device. Power the Pico, then plug in the bricked device’s USB cable.
4. Hold the Pico’s BOOTSEL button until its LED blinks fast, then let go. After about 23 seconds the LED stays on: done. If the LED blinks 1 to 6 times and pauses, look up the number in Troubleshooting.

Remove the cables, then run the ‘i’ command on the Bus Pirate v3 to make sure everything went well:

HiZ>i
Bus Pirate v3.5
Community Firmware v7.1 - buzzpirat.com by Dreg BPCOMP TWELVE [...] Bootloader v4.5

python bp3unbricker.py flash BZ-pickit-firmware-v7.1.12-bootloader-v4.5.hex

The bp3unbricker README has the rest: the Pico’s console, other .hex files, backups, and writing only the bootloader.

Unbrick using another Bus Pirate v3

The Bus Pirate v3 can be used as an inexpensive PIC programmer.

Total cost: ~40$

• Buy a Bus Pirate v3 + USB mini -> USB A cable
• Buy 5 dupont cables FEMALE-FEMALE

Downgrade your Bus Pirate v3 firmware

Download BPv3-Firmware-v5.9-extras.hex firmware from this page:

• https://github.com/therealdreg/buzzpirat/tree/main/bin/oldfirm

Download the last buzzloader app (There are versions available for Windows, Linux and Mac) from this page:

• https://github.com/therealdreg/buzzpirat/tree/main/bin/buzzloader

• put a jumper/dupont_wire connecting the PGD pin to the PGC pin

• connect the Bus Pirate v3 to your computer via a usb cable

• check for the new COM port assignment in the device manager (e.g., COM29)

Make sure to close Tera Term or any other software that might be using the COM port to free it up and execute:

buzzloader.exe --dev=COM29 --hex=BPv3-Firmware-v5.9-extras.hex

Erasing page 41, a400...OK
Writing page 41 row 328, a400...OK
Writing page 41 row 329, a480...OK
Writing page 41 row 330, a500...OK
Writing page 41 row 331, a580...OK
Writing page 41 row 332, a600...OK
Writing page 41 row 333, a680...OK
Writing page 41 row 334, a700...OK
Writing page 41 row 335, a780...OK

Firmware updated successfully :)!
Use screen com30 115200 to verify

Remove the jumper/Dupont cable, then reconnect the device to the USB port, and you’re all set! You should now have the firmware installed.

Run the ‘i’ command and perform a self-test with the ‘~’ command to ensure everything has gone smoothly.

i
Bus Pirate v3b
Firmware v5.9 (r529) [HiZ 2WIRE 3WIRE KEYB LCD DIO] Bootloader v4.5
DEVID:0x0447 REVID:0x3046 (24FJ64GA002 B8)
http://dangerousprototypes.com
HiZ>

Connect to the Bus Pirate v3 to Bricked Buzzpirat / Bricked Bus Pirate v3

Locate the PIC programming pins on the bricked device. Look for the pin named: MCLR.

Connect the pins using Dupont cables in the following manner:

Burn a new bootloader and firmware to the bricked device

If you are unbricking a Buzzpirat. Download the last bootloader + firmware .hex file from this page:

• https://github.com/therealdreg/buzzpirat/tree/main/bin/stablefirm

If you are unbricking a Bus Pirate v3. Download the last bootloader + firmware .hex file from this page:

• https://github.com/therealdreg/buzzpirat/tree/main/bin/stablefirm/bpv3comp

Download the last picprog app from this page:

• https://github.com/therealdreg/buzzpirat/tree/main/bin/picprog

Ensure that both the bricked device and the Bus Pirate v3 are connected to the PC via USB

Make sure to close Tera Term or any other software that might be using the COM port to free it up and execute: (my Bus Pirate v3 is on COM29):

picprog.exe -p buspirate -u COM29 -s 115200 -c 24FJ64GA002 -t HEX -w BZ-pickit-firmware-v7.1.6969-bootloader-v4.5.hex -E

Skipping page 333 [ 0x014d00 ], not used
Skipping page 334 [ 0x014e00 ], not used
Writing page 335, 14f00...
Writing page 336, 15000...
Writing page 337, 15100...
Writing page 338, 15200...
Writing page 339, 15300...
Skipping page 340 [ 0x015400 ], not used
Skipping page 341 [ 0x015500 ], not used
Skipping page 342 [ 0x015600 ], not used
Writing page 343, 15700...

Remove the Dupont cables from MCLR, PGD, PGC, GND, +3v3 pins, then reconnect the bricked device to the USB port, and you’re all set! You should now have the bootloader+firmware installed.

Run the ‘i’ command and perform a self-test with the ‘~’ command to ensure everything has gone smoothly.

HiZ>i
Bus Pirate v3.5
Community Firmware v7.1 - buzzpirat.com by Dreg BZ SIXTHOUSANDNINEHUNDREDSIXTYNINE [HiZ 1-WIRE UART I2C SPI 2WIRE 3WIRE KEYB LCD PIC DIO] Bootloader v4.5
DEVID:0x0447 REVID:0x3046 (24FJ64GA00 2 B8)
http://dangerousprototypes.com
HiZ>

Now, reinstall the latest firmware on your Bus Pirate v3 (the one you used as a PIC programmer).

Unbrick using clones like PICkit3.5

Buy a PICkit3.5 from Aliexpress (an inexpensive PIC programmer).

Total cost: ~30$

Download & install the last pickit minus app from this page:

• https://github.com/therealdreg/buzzpirat/tree/main/bin/pickitminus

If you are unbricking a Buzzpirat. Download the last bootloader + firmware .hex file from this page:

• https://github.com/therealdreg/buzzpirat/tree/main/bin/stablefirm

If you are unbricking a Bus Pirate v3. Download the last bootloader + firmware .hex file from this page:

• https://github.com/therealdreg/buzzpirat/tree/main/bin/stablefirm/bpv3comp

Connect Buzzpirat / Bus Pirate pins to the pins located furthest to the right of the Pickit:

Connect Buzzpirat / Buspirate & Pickit to PC USB

Open the pickitminus app

Go to Tools -> Download PICkit Operating System

Make sure the PIC has been detected: PIC DEVICE FOUND, PIC24FJ64GA002

Select .hex for pickit minus use

Go to File -> Import Hex

And select the Buzzpirat / Buspirate “bootloader + firmware” .hex file (with pickit in its name, example: BZ-pickit-firmware-v7.1.9-bootloader-v4.5.hex)

Click on Write

Done!

Disconnect Buzzpirat / Buspirate & Pickit from PC USB

Unbrick using official MPLAB PICkit 5

Buy a PICkit 5 from Microchip.

Total cost: ~100$

Download & install the last MPLAB X IDE from this page:

https://www.microchip.com/en-us/tools-resources/develop/mplab-x-ide

Connect Buzzpirat / Bus Pirate pins to the pins located furthest to the right of the Pickit:

Connect Buzzpirat / Buspirate & Pickit to PC USB

Open MPLAB IPE (included with MPLAB X IDE):

Select your Pickit Programmer, PIC24FJ64GA002

And click on Connect, after that check that the PICKIT & PIC has been detected: PIC DEVICE FOUND, PIC24FJ64GA002:

Go to Browse and select the Buzzpirat / Buspirate “bootloader + firmware” .hex file (with pickit in its name, example: BZ-pickit-firmware-v7.1.9-bootloader-v4.5.hex)

And click on Program

Done!

Disconnect Buzzpirat / Buspirate & Pickit from PC USB