SIM800C GSM Modem Boards Witty Fox It is installed on the

It is installed on the water inlet end of the water heater to detect the water flow rate

with only two signal lines allowing the MCU to control four 7-segment digital tubes

check out : ULN2003 12V Stepper Motor Driver

1 Channel 5V Active Low Relay Board

lighter weight

SIM800C GSM Modem Boards Witty Fox It is installed on theSIM800C GSM Modem The SIM800C GSM Modem is a quad band GSM GPRS module that supports up to 85. 6kbps of GPRS data transfer. It has a powerful expansion capability and a rich set of interfaces, including UART, USB2. 0, and GPIO. The module provides customers with great flexibility and ease of integration for their applications. Features Quad band GSM GPRS: Supports frequencies 850 900 1800 1900MHz GPRS data transfer up to 85. 6kbps Powerful expansion