Our customer desired a lot of functionality with a very small form factor requirement: 1" x 3" x 5":
1) very-wide-band RF power sensing,
2) on-board digital signal processing capability, and
3) an long-range wireless LoRa link between LoRa devices and the customer's legacy cloud infrastructure
The necessary hardware to support these features, coupled with the small form factor, yielded a large mechanical design effort in an attempt to dissipate the heat produced by the mobile device.
main system board: 32-Bit 200MHz DSP-enhanced processor for data-processing and baseband/gateway inter-communications management, ESP8266 WiFi solution, Haxiot HXC900 LoRa module
sensor interface board: 50MHZ-9GHZ RF power detection (external sensor), video-bandwidth filter (VBF) circuit, 12bit 10MSPS pipelined S/H ADC circuit, 12bit DAC frequency synthesis circuit, 16Mbit flash configuration memory,
LED 'panel' board: system activity indications
environmental: device will be subject to outdoor temperature extremes
power options: ACDC adapter, battery, or solar
battery management: 2-cell Li-Ion charger and fuel gauge
power requirements: low power-consumption requirement in support of battery and <optional> solar-power operations
RF gateway features: WiFi and LoRa with connectorization for external antennae
test: custom VisualC app for system evaluation
