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Using a Bus Pirate to Connect to a Raspberry Pi

The other day I found myself with a Rasberry Pi that I wanted to use but I had forgotten my FTDI UART cable. What I did have is my Bus Pirate v3.6 and I found it was pretty easy to use it’s transpartent UART bridge macro to connect to the Pi. Here’s some of the details:

  • Locate the TX and RX pins on the Pi. These are 8 and 10 respectively.

Rasberry Pi 2 GPIO
  • Locate the TX and RX pins on the Bus Pirate.

Bus Pirate v3.6 pinout
  • Connect TX to RX and RX to TX. Also connect the Bus Pirate ground to one of the Pi’s GPIO ground pins (I’m using pin 6). This is especially important if you are powering the Pi from a source other than the USB bus you are using for the Pirate.

My Pirate and Pi
  • Now connect to your bus pirate using your favorite terminal emulator. I’m on OSX so I use PySerial for this:

    python -m serial.tools.miniterm --lf -b 115200 /dev/tty.usbserial-xxxxxxx
  • Switch to UART mode:

  • Set the UART to 115200, 8, n, 1 and then run the transparent bridge macro:

       > Are you sure?

Now the pirate will act as if you had connected directly to the Pi. Two things to note here; First you have to reset the Bus Pirate to get it out of the transparent UART bridge mode (i.e. Power off/on). Second, if you are using PySerial, you can exit the session using ctrl+].

Now, since you aren’t using ssh to access this Pi I’m guessing the next thing you will need is how to configure the Raspberry Pi WIFI using your terminal.

Finally, if you are setting up a new Pi image you’ll probably want to increase the root partition size. Here’s a great forum post on the topic.

Now go have fun!