Force Sensitive Resistor Sensor FSR 1.4 (Round - 14mm Sensing Diameter) Weight Sensor nfc writer but also can use the

but also can use the digital pin of Arduino to power on and reset the SIM900 module

Dead Band Width < 4 μsec

Download 4-Axis USB CNC Motion Controller for Mach3 driver

Capacitive touch sensor tutorial

13 address input  VCC 16 positive supply voltage

Force Sensitive Resistor Sensor FSR 1.4 (Round - 14mm Sensing Diameter) Weight Sensor nfc writer but also can use theSparkfun force Sensing Resistors (FSR) is a very thin, robust, polymer devices that decrease in resistance when pressure is increased on the surface of the sensor. It is used to sense pressure, weight, contacts and as a touch sensor. These sensors are simple to set up and great for sensing pressure. This FSR will vary its resistance depending on how much pressure is being applied to the sensing area. The harder the force, the lower the resistance.