Giant Butterfly PCB
Allows four HAT or pHAT (or a mix) to be attached to a single Raspberry Pi 40 way connector.
All pins are connected, ID_SD and ID_SC (HAT EEPROM) have cuttable solder jumpers.
For HAT/pHAT with an EEPROM (required by the HAT specification) you will need to cut the ID solder jumpers (with a sharp knife) to prevent conflicts. The EEPROM on the primary HAT (over the Pi) is always connected to the Pi. If at a later date you require the ID pins to be reconnected this can be done by bridging the jumper with solder.
The Giant Butterfly uses a 4-layer PCB to achieve it's small footprint. Due to the traces crossing over each other we do not recommend using it where high frequency signals/switching is required.
When using multiple HATs you MUST check for conflicts - for example enable/select pins when using SPI, I2C addresses and GPIO pin conflicts and modes, I would advise checking on pinout and/or with the HAT seller for used pins/modes in use.
Assembly / Soldering
The Giant Butterfly board is normally used with the "3xMale + 1xLong Female" headers ("Long Female" for the Pi + primary HAT and "Male" for the other HAT positions).
- The top side of the board has the "Giant Butterfly" text and the underside has the ID solder jumpers.
- SEE WARNING BELOW For the primary HAT position put the (optional) header spacer onto the header pins, then push the female header with long pins through from the bottom and soldered into the holes closest to the HAT position marked "RPi".
- Next the 3 male headers can be soldered into the other 3 positions.
- When soldering the long female header onto the Giant Butterfly please be aware of the clearance with the USB/Ethernet connectors on the Raspberry Pi. If you don't use the (optional) header spacer you may want to order/use two Female headers with long pins to give extra clearance.
- Alternatively when soldering the female header you can solder the pins "higher" up instead of having the PCB sat directly on top of the Female part of the connector using the 2.6 mm spacer supplied in the Hardware Kit.
- Either way we strongly recommend applying a couple of layers of electrical insulation tape onto the top of the connector (USB[Pi4]/Ethernet) under the Giant Butterfly board to prevent shorts.
Pin 1 of each HAT position is marked with a white line next to the square pad.
The PCB for sale are black.