Convert a V1.2 cape into a V1.2.1 cape for use with BBB

Background

The Ninja Blocks' Beagle Bone only uses two pins to talk to the cape. When you want to flash the cape, a third pin is used to reset the board.

The Beagle Bone White (BBW) GPIO pin that we had selected for reset has now been re-purposed in the BBB, and is no longer available to us. For this reason we have had to modify the V1.2 schematic to use a different GPIO pin from the BBB.

Since there was an opportunity to modify the schematic, we pulled another GPIO pin to ground to allow the BBB to detect the presence of a V1.2.1 cape.

 

Disclaimer

If you are able to solder, you should successfully complete this tutorial. But if you do something that damages this board we'll not be able to replace it for you.
Take care, and good luck!

 

What you will need

  • Long-nosed pliers
  • soldering iron
  • short wire and solder

 

Modification

Remove previous reset pin connection

Using the long-nosed pliers, carefully bend pin 3 (header P8) as shown:
The reset circuitry from the cape is now separate from the GPIO at pin 3.

 

Connect new reset pin to previous reset pin connection

Solder a wire between Pin 3 and Pin 12 (header P8) as shown:
The reset circuitry is now connected to the GPIO at pin 12 (header P8).

 

Ground a pin to identify V1.2.1

Solder a wire between Pin 12 and ground Pin 1 (header P9) as shown:
The modified board can now be detected via the GPIO at pin 12 (header P9)

 

Success!

The cape can now be used with a BBB.
With the latest utilities and /etc/init scripts (currently in develop) this will continue to work with the BBW too.

 

Happy Hacking!

James Zaki
James Zaki

Author