4×4 Matrix Keypad Module In Pakistan

MQ7 MQ 7 MQ-7 CO Carbon Monoxide Coal Gas Sensor Module For Arduino detects the concentrations of CO in the air and outputs its reading as an analog voltage. The sensor can measure concentrations of 10 to 10,000 ppm. The sensor can operate at temperatures from -10 to 50°C and consumes less than 150 mA at 5 V.This module provides both digital and analog outputs. The threshold level for digital output can be easily adjusted using the preset on the board. The MQ-7 sensor module can be easily interfaced with microcontrollers, Arduino, etc.

MQ6 MQ 6 MQ-6 Liquefied Petroleum isobutane-propane gas Sensor Module For Arduino. This sensor has high sensitivity and fast response time. The sensor’s output is an analog resistance. The drive circuit is very simple; all you need to do is power the heater coil with 5V, add a load resistance, and connect the output to an ADC. The sensitive material of the MQ-6 gas sensor is SnO2, which with lower conductivity in clean air. When the target combustible gas exists, The sensor’s conductivity is higher along with the gas concentration rising. Please use a simple electro circuit, Convert the change of conductivity to correspond output signal of gas concentration.MQ-6 gas sensor has a high sensitivity to Propane, Butane, and LPG, also a response to Natural gas. The sensor could be used to detect different combustible gas, especially Methane, which is with low cost and suitable for different applications.

The MAX9814 is available in the space-saving, 14-pin TDFN package. This device is specified over the -40°C to +85°C extended temperature range. MAX9814 is a low-cost, high-quality microphone amplifier with automatic gain control (AGC) and low-noise microphone bias. The device features a low-noise preamplifier, variable gain amplifier (VGA), output amplifier, microphone-bias-voltage generator, and AGC control circuitry. The low-noise preamplifier has a fixed 12dB gain, while the VGA gain automatically adjusts from 20dB to 0dB, depending on the output voltage and the AGC threshold. The output amplifier offers selectable gains of 8dB, 18dB, and 28dB. With no compression, the cascade of the amplifiers results in an overall gain of 40dB, 50dB, or 60dB. A trilevel digital input programs the output amplifier gain. An external resistive divider controls the AGC threshold and a single capacitor programs the attack/release times. A trilevel digital input programs the ratio of attack-to-release time. The hold time of the AGC is fixed at 30ms. The low-noise microphone-bias-voltage generator can bias most electret microphones.