The ‘Backboard’ provides a ‘managed’ connection to an internal 15v LiPo Battery pack and hosts 2ea 5v regulated power supplies: one (5A) for the esp32 board, all related internal circuits, and the unswitched power at the keyhole. The other 5A is switched and available via a female USB port or pins. Currently, the backboard manages a 12v, 3A power ‘input’. An internal solar MPPT circuit is planned but it will accept 20v (sufficient for ‘12v’ solar systems). Additionally, the backboard hosts 16 channels of 5v outputs. 8 for indicators, 8 for power management circuitry, and passes the ‘daisy-chain’ on.

The ‘keyhole’ is what provides modularity to the Z-Power Management design. Meshtastic enthusiasts will now have ‘unlimited’ number of 5v output channels, RX/TX, I2C, and esp32 Reset (RST) passthrough,  a high-quality I2C Analog-to-Digital Channel, 2 default 5v channels ( Keyhole 1&2) (without daisy-chaining), 5v Power (one switched and one un-switched (sufficient to easily power an external Raspi3B+).

We call this a ‘keyhole’ .. because the supporting case will have a modular ‘slide-in’ design to allow easy attachment of future modules and provide sufficient mechanical connection for future designs.