This Phoenard on-board extension can be connected to the small header on the main board and screwed in with the case. You can then add your own electronic designs to the Phoenard to be carried around with it.If you want one Phoenard, please visit here.FeaturesA 5 x 20 prototyping grid for soldering components to (2.54mm) A group of SMD component sockets are exposed SpecificationsSafe operating conditions Temperature: -10 ~ 60 degrees celcius Humidity: 20% - 90% Power Main board voltage: 3v3 Accessible pins Analog: 6 analog pins (A0 - A5) Digital: 3 general purpose I/O; supports PWM (digital pins 12, 13, 47, shared I/O!) ISP Interface: 4-pin (MISO/MOSI/SCK//GND) I2C Interface: SDA/SCL Power: 3v3 (main board) Part List1 x Phoenon Proto PCBA NoteThis board uses a 3v3 main board voltage and may not be compatible with all 5v sensors and devices. The 5v power on the extension connector is only present when USB power is provided.A starters guide together with documentation and software examples is available on our website:Getting started Software documentation Forums