wbl16a Board Use Notes


Alpha Control Pins from PIC16F628

RB0..RB6 ==> D0..D7 on Alphas A,B,C
RA6..RA7 ==> A0..A1 on Alphas A,B,C
RB7 ==> WR' on Alpha A
RA3 ==> WR' on Alpha B
RA4 ==> WR' on Alpha C

MOSFET pin triggers are RB4 and RB5


I/O Pins And their uses:

RA0 led/transistor 0
RA1 led/transistor 1
RA2 led/transistor 2
RA3 led/transistor 3  ALPHA B WR'
RA4 led/transistor 4  ALPHA C WR'
RA5                                  input with external pull-up
RA6                   ALPHA Addr0
RA7                   ALPHA Addr1
RB0 led b0            ALPHA D0
RB1 led b1            ALPHA D1       serial rx
RB2 led b2            ALPHA D2       serial tx
RB3 led b3            ALPHA D3
RB4                   ALPHA D4       MOSFET 4
RB5                   ALPHA D5       MOSFET 5
RB6 led b6            ALPHA D6
RB7                   ALPHA A WR'

Usage notes.
* LED's b0,b1,b2,b3,b6 reuse the top pins from ALPHA A. Plug in an LED across to the next row down. Add resistor block below that.
* MOSFET 4 and 5 are better used from ALPHA B and ALPHA C WR'. Bend MOSFET pin 1 down to alpha pin 3, instead. handy!
* When running loads on MOSFET and 7805, capacitors across the power planes helps.
-- add a 0.47 or 1.0uF cap on one of the 5v taps.
-- Same for the 12v plane. There's not 12v tap. can use one of the led/transistor points, leftmost pin (3) +, and nearby gnd -.



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Notes for Board Revision:

* Need some 12v/Gnd pairs to add capacitors or other voltage access
* Need THICK traces on the 12v path from transistors & MOSFETs to power (all short)
* Put switched contacts for MOSFET drives just 0.1" apart for the usual plug fitting
* Include holes for at least one button, preferably two; we have a bag o f 'em!
* For MOSFET pins, reuse the '1414's WR' pin, since it is definitely available