MCP3424 18-Bit ADC-4 Channel with Programmable Gain Amplifier

Jargon buster

Plain-language definitions for the technical terms used above.

ADC

An analogue-to-digital converter reads a changing voltage and turns it into a number the microcontroller can use. It matters when connecting analogue sensors such as light, sound, or variable-resistor sensors.

Differential input

A measurement method where the board reads the voltage difference between two input wires instead of measuring one wire compared with ground. This is useful for small sensor signals and noise reduction, but both input voltages still need to stay within the board’s allowed range.

Gain error

Gain error is a scaling error where the DAC output rises slightly too much or too little across its range. It matters for applications where the exact relationship between the digital value and output voltage is important.

I2C

I2C is a two-wire communication bus used by many sensors and small modules. It matters because several I2C devices can share the same two wires, but each device needs a compatible address and your controller must support I2C.

microcontroller

A microcontroller is a small computer on a chip that runs your program and controls connected inputs and outputs. For this product, it is the part that reads buttons and sensors, drives the display and speaker, and communicates over Bluetooth.

Offset error

Offset error is a small output error that appears even when the DAC is set near zero. It matters when your project needs accurate low voltages or fine analogue adjustments.

ppm

ppm means parts per million, a common way to express very small gas concentrations in air. For CO₂ sensors, the ppm range tells you what levels the sensor can measure, such as normal indoor air through to poorly ventilated spaces.

programmable gain

An adjustable amplification setting inside the ADC that makes small input signals larger before they are measured. It matters because choosing the right gain helps use more of the ADC’s range without overloading the input.

Programmable gain amplifier

A built-in amplifier whose gain can be changed in software to make small input signals easier to measure. This matters because choosing the right gain can improve detail for small sensors, but too much gain can make the input range too small.

RTD

An RTD, or resistance temperature detector, is a temperature sensor that changes resistance in a predictable way as it heats or cools. It is useful in water-quality probes because accurate temperature measurement helps correct conductivity readings.

SPS

Samples per second, meaning how many measurements the converter can make each second. Higher SPS gives faster updates, while lower SPS on this board allows higher-resolution readings.

voltage reference

A stable voltage the ADC compares inputs against when converting them to numbers. A more stable reference helps produce more consistent measurements, especially in precision sensing and instrumentation.