Microcontrollers and pull-up / pull-down resistors

In case of GPIOs of microcontrollers, a pull-up resistor is a resistor connected between a signal conductor and a positive power supply voltage while a pull-down resistor is a resistor connected between a signal conductor and a ground. They are used on inputs to prevent floating lines, rapidly switching between high and low and a middle … Read more

What is Serial Peripheral Interface (SPI) ?

Serial peripheral interface (SPI) is a hardware/software communication protocol originally developed by Motorola and widely used by others in the industry. SPI is quite straightforward – it defines how to communicate in easy way between 2 digital devices – i.e. between AVR and devices, like other AVRs, external EEPROMs, DACs, ADCs, etc. SPI is a single-master … Read more