PIC 12F/16F/18F quick start

==Features==
*8bits, 20-48MHz (5-12MIPs), 5volts (lower voltages at reduced speed)
* Huge selection of chips, many still in DIP packages. One of the most complete and full-featured families of microcontroller available on the market. Still manufacturing many "legacy" chips (eg the 16F84 circa 1993).

* PICs use a Harvard architecture where code and data memory are separate, unlike the von Neumann architecture used by the Intel Pentium. PICs use a RISC instruction set with just 35 instructions. All instructions execute in one instruction cycle except for those that modify the program counter such as conditional branches and gotos which always need two cycles.

* One inexpensive, cross-platform (Windows, Linux, Mac OS X) device (Microchip's [http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en023805 PICkit 2], see eBay for clones) programs and debugs most PICs

* Previously famous for a generous sampling program (now dead)

===Reference===

* [http://www.microchip.com/Microchip.WWW.SecureSoftwareList/secsoftwaredownload.aspx?device=en023805&lang=en&ReturnURL=http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en023805# PICkit 2 Programmer User Guide]
* [http://ww1.microchip.com/downloads/en/devicedoc/33023a.pdf PIC mid range manual (16F)]
* [http://ww1.microchip.com/downloads/en/DeviceDoc/39500a.pdf PIC 18F manual]

==Development and programming==

===IDE and compilers===

* Microchip's [http://en.wikipedia.org/wiki/Integrated_development_environment IDE] called [http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&amp;nodeId=1406&amp;dDocName=en019469&amp;part=SW007002 MPLAB]

* [http://devupdates.microchip.com/mplab/Files/installer.html MPLAB X] is Microchip's new cross-platform IDE and compilers for Windows, Linux, and Mac OS X.

* [http://www.microchip.com/C18 Microchip's C18 Compiler for PIC 18F]


We use Microchip's free demonstration compilers with MPLAB. The demo compilers have certain optimizations that expire after 60 days, but we don't use those anyway.

There are many third-party compilers covering C, BASIC, Forth, JAL and Pascal: [[#Resources|See Resources]] below.

===Programmers===

There are many PIC programmers and debuggers, including some that you can build yourself. See [[PIC Resources]] for a brief description of the most commonly used.

===Bootloaders===

PICs do not ship with a bootloader, but there are many that you can program yourself. After the bootloader is installed, a programmer is no longer needed for simple firmware updates.

*[http://mrmackey.no-ip.org/elektronik/ds30loader/ ds30 Loader serial bootloader] for most PICs (GPL), our favorite
*[http://www.diolan.com/pic/bootloader.html Diolan USB HID bootloader for PIC18F] (GPL), another favorite

==Basic circuit==

[[image:quick-pic-basic.png|490px]]

This is the most basic circuit required to program a PIC 18F2550. Most PICs require a similar minimum support circuit.

D1 is only needed by PICs that require a programming voltage greater than the power supply (see [[PIC_quick_start#Reset |reset circuits]] below).

===Power===
*PIC 12/16/18F run at 5volts, and lower voltages at reduced speed
*Connect all the supply pins to power (Vdd) or ground (Vss). Don't forget the AVdd and AVss pins
*Put a 0.1uF decoupling capacitor on each positive supply pin, and put it as close to the chip on your PCB as possible

===Reset===

[[image:quick-pic-reset.png]]

*Reset is the MCLR/VPP pin on PICs (MCLR=master clear, VPP=programming voltage)
*Connect a resistor from MCLR to the supply voltage for normal operation, use 10Kohms for PIC 12/16/18
*The programmer uses 12-13volts on MCLR to put PIC 12F/16F/18F  in programming mode. Use a small diode (D1) between the supply voltage and resistor (R1) to protect the supply voltage from the 13volt programming voltage

===Programming connections===

PICs use a 5 wire programming connection called ICSP in PIC datasheets. This is the prefered pinout order, it's compatible with the PICkit:
#VPP/MCLR - This pin is also the PIC reset pin. Used to enter programming mode, and reset after programming
#Supply voltage (from programmer, or to programmer)
#Ground
#PGD - Program data, a bi-directional data pin (often PORTB7)
#PGC - Program clock (often PORTB6)

Programming a PIC usually requires connecting these five pins to a programmer.

Newer/larger PICs may have multiple pairs of PGC and PGD pins:
*Connect any pair you like
*You need to use the same pair (PGC2 and PGD2, for example)
*It's usually best to check the errata to be sure the pair you chose actually works

===Clock source===

Most PICs have an internal oscillator that can be used as the clock source.

*An external clock source, resonator, or crystal can be attached to the OSC1 (input) and OSC2 pins.
*A secondary, low speed oscillator (T1OSO/T1OSI) is usually available for an external 32.768kHz crystal (real time clock).

==Peripherals==

===IO===

Different PIC pins can source/sink different amounts of current. These are some general rules, but be sure to verify the capabilities in the datasheet for the exact device (usually a table at the beginning of the IO section).
*PORTA-D usually source/sink 25mA
*Others sometimes less

===USB===

[[image:quick-pic-usb-18F.png|490px]]
*18F USB devices (5volt parts) - An internal 3.3volt regulator requires a 0.22uF capacitor on the VUSB pin (we use 2 x 0.1uF), no other connections to VUSB are required
*All PIC USB peripherals have an internal resistors, no other support circuitry is required

==Resources==

See [[PIC Resources]] for more information, third party compilers, operating systems/kernels, hardware (development boards), other tutorials and online PIC programming books.



[[Category:Tutorials]]