Communications module operates as the main module for the complete Solarcast assembly and is primarily a BLE device with other comms modules being plugged in.
- NRF module nRF52832 ANT
- Programmer CMSIS-DAP
- GPS module
- Adafruit FONA 3G module (Note version difference between USA and EU)
- GSM antenna FXUB66.07.0150C
- LORA antenna FXUB66.01.0150C
- BME280 sensor (SDO low 0x76)
- Add accelerometer LIS3DSH footprint for the ic and pins for breakout
- UART MUX SN74LV4052AD SOIC-16
- USB connector to outside world http://eu.mouser.com/ProductDetail/Conxall-Switchcraft/DCP-USBCB-SC/?qs=sGAEpiMZZMulM8LPOQ%252byk0tOUVtDtVQ0KVOITCuLB%252bPJPE9H7T7ELA%3d%3d
- Case: PN-1335
- Add a GPIO expansion port for later work (UART for Air can be on it and I2C and SPI)
- Three internal USB connectors, not carrying USB data
- USB0 - data pins select between I2C and programming pins
- USB1 - data pins select between I2C and programming pins
- USB2 - data pins select between GEIGER0/GEIGER1 and programming pins
- Connector for power module
- 2 groove expansion ports
- External power switch mounted on the box.
Solar operation of the device and minimal power consumption in the standby state govern the design requirements.
Power flow: Solar cell-> Power module (built-in regulators) -> Comms module -> Power switch and fan out to:
- Switch high-side 5V - USB0 for Air module - ENABLE-AIR - 250mA peak - TPS2034D regulated from battery pack
- Switch high-side 5V - USB1 for Geiger module - ENABLE-GEIG - 50mA peak - TPS2034D regulated from battery pack
- Switch high-side 5V - USB2 -reserve- 1A peak TPS2034D
- Switch high-side 5V - backup - 1A peak TPS2034D
Power switch disconnects power between power module and comms module.
Add headers for mosfet bypass for current consumption measurement and jumpers prior to voltage regulators.
The board is designed as a main board with all other modules connecting to it.