Quantity   Component name
1 × ESP8266 ESP-201 type, with antenna
1 × Tiny DC-DC converter Input voltage: 4.5-28V, Output Voltage: 0.8-20V (adjustable)
4 × Resistor 4.7 kOhm
1 × 9V dry battery
1 × 9V battery connector
2 × female pin header, 11 pins
1 × male pin header, 3 pins
1 × Iron wire
1 × Jumper Electronic Components / Misc. Electronic Components