Synergy CR1616 3V Lithium BatteryThe Synergy CR1616 Lithium Coin Cell is a high capacity replacement battery that's commonly found in calculators, heart rate monitors, remote starters, thermometers, and other tiny electronic devices. This small size battery is made up of Lithium Manganese Dioxide chemistry that not only supplies the cell with the high voltage required for high performance devices but also has a very low self discharge rate, extending the battery's shelf life.

This 8 Way DIP SPST Switch is the simplest type of switch in which a single toggle either connects or disconnects a single terminal from other

and other components

It's a DC 12V Single Channel Relay Module RF Wireless Switch Receiver + Remote Control Transmitter DIY Kit 433mhz

which can be used also for serial in/serial out operations

the LEDs start glowing

Gold for these 7K5 resistors

0 Brand Unisonic Technologies Maximum Supply Voltage 45V Saturation Voltage 5V Current Limit  3A Efficiency 82% Feedback Voltage 1

PWM control

Switch-mode power supplies

54mm JST Female Connector

This board is assembled with an ESP-WROOM-32 Module and has the standard UNO size and connectors

The USB Charger Doctor is a tool for measuring the working voltage and current output of any USB port and project