A PIC (Programmable Interface Controller) is an unbelievably cheap programmable device containing a CPU, some Flash memory (for your program code) and a limited amount of RAM. Low end ('12F') devices can be found on eBay for less than 20p each, contain an 8bit CPU, up to a kb of program space (Flash memory), a few dozen bytes of RAM and 4 to 6 i/o pins (the function of which is under your program control). All have built in timer/counter(s) and most have serial comms (I2C, SPI) circuits and some support 'Interrupts'. Some even have a built-in A-D converter and a dozen or so bytes of EEPROM ! They typically run at 1 MIPS.
Even the 'high end' PICs typically cost less than £5 each, for which you get a 16bit CPU running at 16MIPS (or so), multi-kb's of Flash instruction space (up to about 192kb), a few kb of RAM register space (up to about 8kb) and even some user EEPROM. Designed to run C program code they come with multiple 'built in' support components (such as a 10bit ADC, I2C, UART and even USB !)
However, with the advent of the £4 ($5) Pi Zero, a 'game changer' has entered the programmable device market. The Pi Zero (512Mb RAM, 1GHz +GPU on-board HDMI) is at least 3 'orders of magnitude' more powerful than any PIC device. The future of programmable device DIY projects should be very interesting indeed !
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+ 16 keypad 4x4 matrix - (using one pin) == Latest changes (modified 29th May 2018 14:37.)
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