Here is a teardown of a 'ELVICO Smart Plug', It is intended for Zigbee using the eWelink platform. I have been hunting for bouffalolab-based
devices as my project has been porting those chips to zephyr RTOS for a
few years, and we just got BLE working, enabling usages similar to
openbeken or tasmota.
The marking on the outside is 'ELC-SP02'. The case is thick plastic and
heat-closed by tabs on the edges and very hard to open. The board inside
is held by a single screw then easily pulls out.
The design is as such:
Ground is passed through from front to back.
Zigbee is provided by a BL702C10 chip with date markings of 2025, mounted on a
EWL-ZBS02-LG_V2 Module marked 2023 (??). This is a 1 megabyte flash
version, and the module provides its 32Mhz crystal but not much else.
The energy metering chip is BL0937, there are 2 leds available to control and a button.
5v power is provided by a BP2525 chip, and 3v3 power is provided by an AMS1117 LDO.
The switching capacity is provided by a 'FANHAR' FH17-1A2TLE 5v relay.
The button is connected to GPIO27, LED 1 is connected to GPIO8, LED 2 is also connected to GPIO27 via 10Kohms resistor.
BL0937 CF, CF1 and SEL go to the chip via 1KOhms resistors. CF goes to GPIO2, CF1 goes to GPIO1, SEL goes to GPIO15.
The relay is driven by GPIO14->1.5KOhms->mosfet.
devices as my project has been porting those chips to zephyr RTOS for a
few years, and we just got BLE working, enabling usages similar to
openbeken or tasmota.
The marking on the outside is 'ELC-SP02'. The case is thick plastic and
heat-closed by tabs on the edges and very hard to open. The board inside
is held by a single screw then easily pulls out.
The design is as such:
Ground is passed through from front to back.
Zigbee is provided by a BL702C10 chip with date markings of 2025, mounted on a
EWL-ZBS02-LG_V2 Module marked 2023 (??). This is a 1 megabyte flash
version, and the module provides its 32Mhz crystal but not much else.
The energy metering chip is BL0937, there are 2 leds available to control and a button.
5v power is provided by a BP2525 chip, and 3v3 power is provided by an AMS1117 LDO.
The switching capacity is provided by a 'FANHAR' FH17-1A2TLE 5v relay.
The button is connected to GPIO27, LED 1 is connected to GPIO8, LED 2 is also connected to GPIO27 via 10Kohms resistor.
BL0937 CF, CF1 and SEL go to the chip via 1KOhms resistors. CF goes to GPIO2, CF1 goes to GPIO1, SEL goes to GPIO15.
The relay is driven by GPIO14->1.5KOhms->mosfet.
