Overview
This reference design offers both metering and WiFi capabilities:
- Metering - used to measure electronic power in single-phase and,
- WiFi - used for wireless control.
Plug status can be checked via a smart-phone application, including current active power, reactive power, grid frequency, history runtime. On/Off setting timer available as well.
Features
- Based on Kinetis MKM14Z64 MCU
- WIFI module based on QFM2202
- 220V input voltage, 10A max current
- Phase current sampling with 25ppm 5 mΩ current sampler by 24Bit SD ADC
- Phase voltage sampling with 25ppm resistor voltage divider network by 24Bit SD ADC
- On-chip voltage comparator (for precision grid frequency detection)
- Single 32.788K crystal input for 5ppm RTC
- External extendable 64Mb SPI Flash
- Low-power modes including the use of built-in RTC
- 3 channel LED pulse outputs for calibration(kWh, kVarh)
- Provide android application to get active power, reactive power, apparent power, grid frequency and history runtime
- Android application to set plug ON/Off, set timer for ON/Off at fixed time and set RTC time
- Android application to set plug wifi module to power save mode
- Cost-effective bill of materials
- External extendable WIFI module with UART connection
Block Diagram
Design Resources