Printed circuit boards (PCBs) are what usually come to mind when people think of electronic circuits. Although commercial products all use PCBs, they are comparatively rare in do-it-yourself projects. One-of-a-kind electronic circuit-makers rarely have the resources necessary to take an electronic circuit into PCB layout or produce the PCB. Some PCB projects use a microcontroller. The program code required for the microcontroller in each of these projects is available with the PCB plans.
Arduino Solar Day Night Controller
This project creates a way for you to turn on lights at dusk and off at dawn. The Arduino Solar Day Night Controller is an open-source project that turns on low-power lights at dusk and turns them off at dawn. This project demonstrates the power of a microcontroller to simplify hardware circuitry. You can either buy or make the hardware for this project. The PCB can be made using any regular PCB layout process. Because this is an Open Source project, you can find the free PCB plans and the microcontroller code on the Arduino website.
Digital Multiple Voltage Power Supply
The Digital Multiple Voltage Power Supply provides voltage-regulated outputs from 1.2 to 33 volts distributing current at up to three amps. The microcontroller is stepped up or down by two single-pole-single-throw switches. The project currently provides for five regulated outputs, but can be modified for up to 32.
This project uses an Atmel ATTINY2313 Microcontroller. It is an eight-bit reduced instruction set microcontroller with 2KB of in-system self-programmable flash memory, 128 bytes in-system programmable EEPROM memory, and 128 bytes internal SRAM memory. It has a universal serial interface, full duplex UART and debugWIRE for on-chip-debug. Its performance is up to 20 MIPS throughput at 20 MHz and 1.8 - 5.5 volt operation. Resource 2 contains both the plans for the PCB and the microcontroller programming code.
PIC16F84A Gas Detector
This gas detector uses a GH-312 sensor. The GH-312 is capable of sensing gases like smoke, butane, propane, methane, liquefied gas, hydrogen and alcohol. The gas detector uses a PIC16F84A microcontroller, which is manufactured by Texas Instruments and is available from several vendors. It is an RISC, 8-bit, MCU with 68 bytes of data RAM and 64 bytes of data EEPROM. The source code you need for the microcontroller is included with the plans.
