Progetti - PIC

18-pin miniDemoBoard

Description.

The miniBoard is scheduled for all PIC mid-range and enhanced 18-pin, as 16F88, 16F84, 16F628, 18F1230, 18F1330 and the like.

The miniBoard has been designed to be plugged directly on a breadboard.

This allows to have ready the entire support structure of the processor without replicate every time.

Simply power the board and assemble the external parts.

The circuit is the minimum that is around the chip: the miniDemoBoard is ultra simple, but as a basis for experimenting with embedded microcontrollers do not need anything else.

The board is small in size (58 x 39 mm or so), but it contains everything you need to run the PIC:

power connections and decoupling capacitors
reset circuit with various options
clock circuit with various options
connector ICSP / ICD
plug 's listing on breadboard
small test set of LED on-board
connectors and test points for small test on-board

The scheme is the application of the chip embedded, with the possibility of a series of options:

Power supply.

Vdd/Vss can be conntected to the board by the breadboard's connector:

pin 1-2-11 Vss
pin 12-21-22 Vdd

But the 'power can also arrive at the ICSP connector: the PICkit can deliver power to the connected circuit, within the limits specified by the manufacturer, can tap power from the USB connection and power circuits also quite complex.

Furthermore the connection ICSP / ICD with PICKit allows also to use the card as a support for stand-alone programming without the need to external power.

A 0.1 uF capacitor (C1, multilayer, 50 V, pitch 2.52 ") and an electrolyte (C2, 4.7 uF tantalum - aluminum or 10 uF - 10 V) work fine even if the cable between the card and power supply are not short .

It was expected to supply on-board because for ICSP / ICD is unnecessary and would be limiting in other applications the PIC operate between 2 V (LF) and 5 V and may be interesting to experiment with these possibilities.
Nothing prevents, however, to be an ad hoc circuit carrying the classic three terminals.

Powering the breadboard

To power the breadboard, nothing better form UBS-12

UBS-12, is a DC / DC converter, battery-powered, tyhan:

no network connection is necessary
can be derived stabilized voltages from 2 to 5.2V with currents up to 400 mA