JoyKontrol - Schematic

BUFFER sub-circuit	BOOSTER sub-circuit

After I had build the circuit I found that the adjustment range of RV5, etc. to set the joystick centre points to 0V is barely sufficient to cope with the variations from joystick to joystick, so it would be better to use 50K trimmers for RV5, etc. and 180K resistors for R17, etc.

The BOOSTER sub-circuits were a last minute addition so they are rather squeezed onto the schematic. (When I initially calculated the LED current drawn from the PIC I/O pins, I calculated for 1 segment only and completely missed the fact that the common anode connections need up to 8 times this current!) The 2SC732 transistor is a bit of an unusual choice for this application - it was only used because I have a big bag of them - any general purpose NPN will work.

The LED display used is an Kingbright Triple 7-segment LED display (Red, Common Anode) BA56-12EWA, available from Rapid Electronics in UK. Note that the LED jumper pin numbers do not correspond to the pin numbers of the LED unit itself - this was done to make the routing on the stripboard easier. Note also that there is no pin 6 on either the jumper or the LED unit. The pins correspond as follows:

Jumper pin	LED pin
1	4
2	2
3	1
4	10
5	5
7	3
8	8
9	9
10	7
11	11
12	12

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