One of the most basic communication protocols in electronics is the Universal Asynchronous Receive Transmit (UART) serial protocol. The UART protocol allows for two devices to communicate with each other. The protocol requires two wires between the devices that are communicating; one for each direction of communication. Each device has an independent transmit and receive [...]

Serial Peripheral Interface, or SPI, was developed in the late 1980's and was quickly adopted as the standard communication protocol for embedded systems. SPI is intended for communicating over short distances at relatively high speeds. The protocol allows one master per bus and many slave devices. The master differentiates between the slaves by activating the [...]

When trying to interface with an IC or hardware module, it is always nice to be able to reuse program code that someone else already went through the trouble of writing. This lets you skip the work of writing the basic interface and puts you at a much better starting point. Software libraries are a [...]

Digital input and output is one of the most basic operations of a microcontroller. All of the pins on an Arduino board (0-13 & A0-A5) can be used as digital inputs or outputs in addition to any other function (e.g. analog input) connected to the pin.   Digital Input When we talk about digital input, [...]

While digitally reading if a pin is high or low is great, it's not very helpful with an analog sensor. In this case, we need to know the voltage of the pin. There is a device built into most microcontrollers called an analog-to-digital converter (ADC) that makes this possible. The ADC compares the voltage on [...]

PWM Duty Varying between 0% and 100% Pulse width modulation (PWM) is a way of creating an analog signal from digital pulses. A PWM has two parameters: the frequency of the PWM and the duty of the PWM. The frequency of a PWM is how often it is pulsing. If you have a [...]