Summary of Mini project board for PIC12F series microcontrollers
Summary: A compact development board for PIC12F 8-pin microcontrollers provides a regulated +5V supply, ICSP header for PICKit2/3 programming, reset/tact switch on GP3/MCLR, accessible I/O headers (GP0, GP1, GP2, GP4, GP5, GP3 via PTH), a small prototyping area, and a 2-pin terminal for 6–12V external power. Power uses an AMS1117-5.0 regulator (recommended max 500mA). Pads/SW2 allow adding or bypassing an external ON/OFF switch; PD1 pads must be shorted for continuous power.
Parts used in the Mini project board for PIC12F series microcontrollers:
- PIC12F series microcontroller (8-pin)
- AMS1117-5.0 voltage regulator
- 2-pin terminal block for 6–12V input
- ICSP header for PICKit2/3
- IC socket for PIC12F
- Tact switch for GP3/MCLR
- Header connectors for I/O pins (GP0, GP1, GP2, GP4, GP5, +5V, GND)
- Plated through hole labeled GP3
- Reset circuit components (resistor/capacitor as per reset design)
- Small prototyping area (PCB pads)
- PTH pads for SW2 or PD1 power jumper
The 12F series of PIC microcontrollers are handy little 8-pin devices designed for small embedded applications that do not require too many I/O resources, and where small size is advantageous. These applications include a wide range of everyday products such as hair dryers, electric toothbrushes, rice cookers, vacuum cleaners, coffee makers, and blenders.
Despite their small size, the PIC12F series microcontrollers offer interesting features including wide operating voltage, internal programmable oscillator, 4 channels of 10-bit ADC, on-board EEPROM memory, on-chip voltage reference, multiple communication peripherals (UART, SPI, and I2C), PWM, and more. The following project board is designed for fast and easy development of standalone applications using PIC12F microcontrollers. It features an on-board regulated +5V power supply, header connectors to access I/O pins, an ICSP header for programming, a reset circuit, and a small prototyping area for placing additional components.
Circuit diagramThe following circuit shows the on-board +5V power supply unit using AMS1117-5.0V regulator IC. The maximum output current of AMS1117 is 800mA, but it is recommended to limit the maximum current to 500mA. The project board can be powered from a 6-12V external power supply connected through a 2-pin terminal block. There is no power ON/OFF switch on-board but users can connect one externally. If no external ON/OFF switch is connected, the pads shown in the figure below must be shorted through soldering.
The microcontroller circuit (shown below) is straightforward. The GP3/MCLR pin is connected to an external tact switch that can be configured as a reset switch (if MCLR is enabled) or a user input (if MCLR is disabled). All I/O (GP0, GP1, GP2, GP4, and GP5) and power supply (+5V and GND) pins are accessible through headers. A header connector for ICSP using PICKit2/3 is also provided on board.
Although GP3 is connected to the tact switch input, you can still access it through a plated through hole (PTH) on lower right side of PIC12F IC socket and is labelled as GP3 on PCB (see picture below). There’s a small prototyping area available on the board to add additional components for user projects. If an external ON/OFF switch is to be added into your application, it must be connected to two PTH marked as SW2. Otherwise, the PD1pins must be shorted together for continuous power supply. The picture below shows a closer view of the features on board.
For more detail: Mini project board for PIC12F series microcontrollers
- What power input voltage does the board accept?
The board accepts a 6–12V external power supply via the 2-pin terminal block. - What voltage regulator is used on the board?
The board uses an AMS1117-5.0 voltage regulator for the on-board +5V supply. - What is the recommended maximum current draw from the AMS1117 on the board?
Although AMS1117 can output up to 800mA, the article recommends limiting the maximum current to 500mA. - How can the board be powered continuously without an external switch?
If no external ON/OFF switch is connected, the PD1 pads must be shorted together for continuous power supply. - How is GP3/MCLR connected on the board?
GP3/MCLR is connected to an external tact switch that can act as a reset (if MCLR enabled) or as a user input (if MCLR disabled), and GP3 is also accessible via a plated through hole labeled GP3. - Which I/O pins are exposed via headers on the board?
GP0, GP1, GP2, GP4, GP5, and power pins (+5V and GND) are accessible through headers; GP3 is available via a PTH. - Is there support for in-circuit programming on the board?
Yes, there is an ICSP header provided for programming with PICKit2/3. - Where should an external ON/OFF switch be connected?
An external ON/OFF switch should be connected to the two PTH pads marked SW2. - Does the board include space for adding extra components?
Yes, the board includes a small prototyping area for placing additional components.
