Collection of Instructables with microcontroller based step-down, buck-boost, and boost converters. The converters are constant current, constant voltage, or both. Their applications include: DIY DC power supply, LED drivers, battery chargers, and electrolysis.
In microcontroller based DC-DC converters, the programmed chip reads the output current or voltage and generates a PWM output to drive the switch rather than using a dedicated chip to do the job.
Compared to using dedicated IC's, the advantages of this method include reduced power consumption in sleep mode, adjustable drive current, adjustable maximum duty cycle, the ability to make certain adjustments by only changing the program, and the ability to use the remaining pins on the chip.