Electronic Tic-Tac-Toe
5 May 2007Progress: Completed
My GCSE Systems & Control project. Far more complicated than needed, but hey, I had a lot of spare time back then.
The original write-up is in Welsh, and after years of thinking "I'll translate it later" I've decided to just post the pictures with minimal explanation.
The LEDs go red for a cross, and green for a naught.
9 input switches, 9 tricolour LEDs as output. The biggest chip I was allowed to use was the PICAXE-18X, with 9 output pins. The tricolour LEDs obviously needed two pins each, so after experimenting with linking multiple chips together and things like that, I stumbled upon an article explaining how to matrix LEDs – which solved the problem perfectly.
Essentially you place the LEDs in a grid, and illuminate one row/column at a time, and cycle through the matrix so fast that it appears they're all lit, thanks to persistence-of-vision. My grid was 3x6, the 6 being the reds and greens, the 3 being the ground wires.
My solution for the inputs was to place a different resistor on each and connect them all to the same analogue input pin. This would then work out which had been pressed from the reading. In retrospect, it would have been easier to just matrix the switches too.
Sadly the analogue readings varied greatly depending on battery life, so I had to add a calibration step when you turned the thing on. Less than ideal, but functional.
I was pretty pleased with this when I finished, but there are infinitely many ways it could have been better. Anyway, pictures.
This doesn't really do justice to the amount of effort it took to get the matrix working.
I had never used a picaxe before, but the Basic they're programmed with is pretty simple. The final code only just fit on the chip, with something like 5 bytes of free space.
''' Roar control of outputs. ' % ' 0 mid row negative ' 0 bottom row negative ' 0 top row negative ' 0 G3 ' 0 R2 ' 0 G2 ' 0 R1 ' 0 G1 ' SERTXD R3 ' % 0 0 0 0 0 0 0 0 ' 128 64 32 16 8 4 2 1 ''' Finalized control of outputs ' b10 = top row ' b11 = mid row ' b12 = bot row ' % ' 0 - Leave blank ' 0 - Leave blank ' 0 R3 ' 0 G3 ' 0 R2 ' 0 G2 ' 0 R1 ' 0 G1 main: symbol TopRow = b10 symbol MidRow = b11 symbol BotRow = b12 symbol inp1 = b1 let inp1 = 0 symbol inp2 = b2 let inp2 = 0 symbol inp3 = b3 let inp3 = 0 symbol inp4 = b4 let inp4 = 0 symbol inp5 = b5 let inp5 = 0 symbol inp6 = b6 let inp6 = 0 symbol inp7 = b7 let inp7 = 0 symbol inp8 = b8 let inp8 = 0 symbol inp9 = b9 let inp9 = 0 'Calibrate inputs calib1: let pins = %10100011 poke $05,%00000000 readadc 2,b0 if b0 = 0 then goto calib1 do while b0 <> 0 if b0>inp1 then let inp1 = b0 endif readadc 2,b0 loop calib2: let pins = %10101100 poke $05,%00000000 readadc 2,b0 if b0 = 0 then goto calib2 do while b0 <> 0 if b0>inp2 then let inp2 = b0 endif readadc 2,b0 loop calib3: let pins = %10110000 poke $05,%00001000 readadc 2,b0 if b0 = 0 then goto calib3 do while b0 <> 0 if b0>inp3 then let inp3 = b0 endif readadc 2,b0 loop calib4: let pins = %01100011 poke $05,%00000000 readadc 2,b0 if b0 = 0 then goto calib4 do while b0 <> 0 if b0>inp4 then let inp4 = b0 endif readadc 2,b0 loop calib5: let pins = %01101100 poke $05,%00000000 readadc 2,b0 if b0 = 0 then goto calib5 do while b0 <> 0 if b0>inp5 then let inp5 = b0 endif readadc 2,b0 loop calib6: let pins = %01110000 poke $05,%00001000 readadc 2,b0 if b0 = 0 then goto calib6 do while b0 <> 0 if b0>inp6 then let inp6 = b0 endif readadc 2,b0 loop calib7: let pins = %11000011 poke $05,%00000000 readadc 2,b0 if b0 = 0 then goto calib7 do while b0 <> 0 if b0>inp7 then let inp7 = b0 endif readadc 2,b0 loop calib8: let pins = %11001100 poke $05,%00000000 readadc 2,b0 if b0 = 0 then goto calib8 do while b0 <> 0 if b0>inp8 then let inp8 = b0 endif readadc 2,b0 loop calib9: let pins = %11010000 poke $05,%00001000 readadc 2,b0 if b0 = 0 then goto calib9 do while b0 <> 0 if b0>inp9 then let inp9 = b0 endif readadc 2,b0 loop tictac: 'debug b1 'debug b2 'debug b3 'debug b4 'debug b5 'debug b6 'debug b7 'debug b8 'debug b9 'readadc 2,b0 'debug b0 'Right. b13 is now the current turn - 0 for red and 1 for green. 'Wait for input. readadc 2,b0 if b0<>0 then if b0 = inp1 then goto pushed1 if b0 = inp2 then goto pushed2 if b0 = inp3 then goto pushed3 if b0 = inp4 then goto pushed4 if b0 = inp5 then goto pushed5 if b0 = inp6 then goto pushed6 if b0 = inp7 then goto pushed7 if b0 = inp8 then goto pushed8 if b0 = inp9 then goto pushed9 let b0 = b0-1 'allow for error if b0 = inp1 then goto pushed1 if b0 = inp2 then goto pushed2 if b0 = inp3 then goto pushed3 if b0 = inp4 then goto pushed4 if b0 = inp5 then goto pushed5 if b0 = inp6 then goto pushed6 if b0 = inp7 then goto pushed7 if b0 = inp8 then goto pushed8 if b0 = inp9 then goto pushed9 let b0 = b0+2 'allow for error if b0 = inp1 then goto pushed1 if b0 = inp2 then goto pushed2 if b0 = inp3 then goto pushed3 if b0 = inp4 then goto pushed4 if b0 = inp5 then goto pushed5 if b0 = inp6 then goto pushed6 if b0 = inp7 then goto pushed7 if b0 = inp8 then goto pushed8 if b0 = inp9 then goto pushed9 endif let b0 = 0 draw1: if b10 >= 32 then goto nineonrow1 ' if output 9 is on let pins = b10 + 64 + 128 ' 64 and 128 are the disabled rows, 2 and 3 poke $05,%00000000 ' 9 is off pause 1 goto draw2 nineonrow1: let pins = b10 + 32 + 128 ' take 32, as that's the temp bit we used to identify the 9th poke $05,%00001000 ' 9 on pause 1 goto draw2 draw2: if b11 >= 32 then goto nineonrow2 let pins = b11 + 64 + 32 'disable other pins etc poke $05,%00000000 pause 1 goto draw3 nineonrow2: let pins = b11 + 32 + 32 poke $05,%00001000 pause 1 goto draw3 draw3: if b12 >= 32 then goto nineonrow3 let pins = b12 + 128 + 32 poke $05,%00000000 pause 1 goto tictac nineonrow3: let pins = b12 + 128 poke $05,%00001000 pause 1 goto tictac 'b0 now becomes the comparison variable pushed1: 'First, if our bit is already set, do nothing b0 = BotRow ^ %00000010 ' Red if b0 < BotRow then goto draw1' if the bit IS set b0 = BotRow ^ %00000001 ' Green if b0 < BotRow then goto draw1 if b13 = 0 then let BotRow = BotRow ^ %00000010 else let BotRow = BotRow ^ %00000001 endif goto afterpush pushed2: b0 = BotRow ^ %00001000 if b0 < BotRow then goto draw1 b0 = BotRow ^ %00000100 if b0 < BotRow then goto draw1 if b13 = 0 then let BotRow = BotRow ^ %00001000 else let BotRow = BotRow ^ %00000100 endif goto afterpush pushed3: b0 = BotRow ^ %00100000 if b0 < BotRow then goto draw1 b0 = BotRow ^ %00010000 if b0 < BotRow then goto draw1 if b13 = 0 then let BotRow = BotRow ^ %00100000 else let BotRow = BotRow ^ %00010000 endif goto afterpush pushed4: b0 = MidRow ^ %00000010 if b0 < MidRow then goto draw1 b0 = MidRow ^ %00000001 if b0 < MidRow then goto draw1 if b13 = 0 then let MidRow = MidRow ^ %00000010 else let MidRow = MidRow ^ %00000001 endif goto afterpush pushed5: b0 = MidRow ^ %00001000 if b0 < MidRow then goto draw1 b0 = MidRow ^ %00000100 if b0 < MidRow then goto draw1 if b13 = 0 then let MidRow = MidRow ^ %00001000 else let MidRow = MidRow ^ %00000100 endif goto afterpush pushed6: b0 = MidRow ^ %00100000 if b0 < MidRow then goto draw1 b0 = MidRow ^ %00010000 if b0 < MidRow then goto draw1 if b13 = 0 then let MidRow = MidRow ^ %00100000 else let MidRow = MidRow ^ %00010000 endif goto afterpush pushed7: b0 = TopRow ^ %00000010 if b0 < TopRow then goto draw1 b0 = TopRow ^ %00000001 if b0 < TopRow then goto draw1 if b13 = 0 then let TopRow = TopRow ^ %00000010 else let TopRow = TopRow ^ %00000001 endif goto afterpush pushed8: b0 = TopRow ^ %00001000 if b0 < TopRow then goto draw1 b0 = TopRow ^ %00000100 if b0 < TopRow then goto draw1 if b13 = 0 then let TopRow = TopRow ^ %00001000 else let TopRow = TopRow ^ %00000100 endif goto afterpush pushed9: b0 = TopRow ^ %00100000 if b0 < TopRow then goto draw1 b0 = TopRow ^ %00010000 if b0 < TopRow then goto draw1 if b13 = 0 then let TopRow = TopRow ^ %00100000 else let TopRow = TopRow ^ %00010000 endif goto afterpush afterpush: if b13 = 0 then let b13 = 1 else b13 = 0 endif 'Now we need to check for certain patterns. 'Check for the eight winning lines, times the two colours ' R R R ' - - - ' - - - let b0 = TopRow ^ %00100000 if b0 < TopRow then 'if it was on let b0 = TopRow ^ %00001000 if b0 < TopRow then let b0 = TopRow ^ %00000010 if b0 < TopRow then 'Yay, show red topline winning animation let pins = %11001010 poke $05,%00001000 pause 500 let pins = %00000000 poke $05,%00000000 pause 250 let pins = %11001010 poke $05,%00001000 pause 500 goto reset endif endif endif ' G G G ' - - - ' - - - let b0 = TopRow ^ %00010000 if b0 < TopRow then 'if it was on let b0 = TopRow ^ %00000100 if b0 < TopRow then let b0 = TopRow ^ %00000001 if b0 < TopRow then let pins = %11010101 poke $05,%00000000 pause 500 let pins = %00000000 pause 250 let pins = %11010101 pause 500 goto reset endif endif endif ' - - - ' R R R ' - - - let b0 = MidRow ^ %00100000 if b0 < MidRow then 'if it was on let b0 = MidRow ^ %00001000 if b0 < MidRow then let b0 = MidRow ^ %00000010 if b0 < MidRow then let pins = %01101010 poke $05,%00001000 pause 500 let pins = %00000000 poke $05,%00000000 pause 250 let pins = %01101010 poke $05,%00001000 pause 500 goto reset endif endif endif ' - - - ' G G G ' - - - let b0 = MidRow ^ %00010000 if b0 < MidRow then 'if it was on let b0 = MidRow ^ %00000100 if b0 < MidRow then let b0 = MidRow ^ %00000001 if b0 < MidRow then let pins = %01110101 poke $05,%00000000 pause 500 let pins = %00000000 pause 250 let pins = %01110101 pause 500 goto reset endif endif endif ' - - - ' - - - ' R R R let b0 = BotRow ^ %00100000 if b0 < BotRow then 'if it was on let b0 = BotRow ^ %00001000 if b0 < BotRow then let b0 = BotRow ^ %00000010 if b0 < BotRow then let pins = %10101010 poke $05,%00001000 pause 500 let pins = %00000000 poke $05,%00000000 pause 250 let pins = %10101010 poke $05,%00001000 pause 500 goto reset endif endif endif ' - - - ' - - - ' G G G let b0 = BotRow ^ %00010000 if b0 < BotRow then 'if it was on let b0 = BotRow ^ %00000100 if b0 < BotRow then let b0 = BotRow ^ %00000001 if b0 < BotRow then let pins = %10110101 poke $05,%00000000 pause 500 let pins = %00000000 pause 250 let pins = %10110101 pause 500 goto reset endif endif endif ' R - - ' R - - ' R - - let b0 = TopRow ^ %00100000 if b0 < TopRow then 'if it was on let b0 = MidRow ^ %00100000 if b0 < MidRow then let b0 = BotRow ^ %00100000 if b0 < BotRow then let pins = %00000000 poke $05,%00001000 pause 500 poke $05,%00000000 pause 250 poke $05,%00001000 pause 500 goto reset endif endif endif ' G - - ' G - - ' G - - let b0 = TopRow ^ %00010000 if b0 < TopRow then 'if it was on let b0 = MidRow ^ %00010000 if b0 < MidRow then let b0 = BotRow ^ %00010000 if b0 < BotRow then let pins = %00010000 poke $05,%00000000 pause 500 let pins = %00000000 pause 250 let pins = %00010000 pause 500 goto reset endif endif endif ' - R - ' - R - ' - R - let b0 = TopRow ^ %00001000 if b0 < TopRow then 'if it was on let b0 = MidRow ^ %00001000 if b0 < MidRow then let b0 = BotRow ^ %00001000 if b0 < BotRow then let pins = %00001000 poke $05,%00000000 pause 500 let pins = %00000000 pause 250 let pins = %00001000 pause 500 goto reset endif endif endif ' - G - ' - G - ' - G - let b0 = TopRow ^ %00000100 if b0 < TopRow then 'if it was on let b0 = MidRow ^ %00000100 if b0 < MidRow then let b0 = BotRow ^ %00000100 if b0 < BotRow then let pins = %00000100 poke $05,%00000000 pause 500 let pins = %00000000 pause 250 let pins = %00000100 pause 500 goto reset endif endif endif ' - - R ' - - R ' - - R let b0 = TopRow ^ %00000010 if b0 < TopRow then 'if it was on let b0 = MidRow ^ %00000010 if b0 < MidRow then let b0 = BotRow ^ %00000010 if b0 < BotRow then let pins = %00000010 poke $05,%00000000 pause 500 let pins = %00000000 pause 250 let pins = %00000010 pause 500 goto reset endif endif endif ' - - G ' - - G ' - - G let b0 = TopRow ^ %00000001 if b0 < TopRow then 'if it was on let b0 = MidRow ^ %00000001 if b0 < MidRow then let b0 = BotRow ^ %00000001 if b0 < BotRow then let pins = %00000001 poke $05,%00000000 pause 500 let pins = %00000000 pause 250 let pins = %00000001 pause 500 goto reset endif endif endif ' R - - ' - R - ' - - R let b0 = TopRow ^ %00100000 if b0 < TopRow then 'if it was on let b0 = MidRow ^ %00001000 if b0 < MidRow then let b0 = BotRow ^ %00000010 if b0 < BotRow then 'Matrix the display again let b0 = 0 do while b0 < 100 let pins = %11000000 poke $05,%00001000 pause 1 let pins = %01101000 poke $05,%00000000 pause 1 let pins = %10100010 pause 1 b0 = b0 + 1 loop let pins = 0 poke $05,%00000000 pause 250 let b0 = 0 do while b0 < 100 let pins = %11000000 poke $05,%00001000 pause 1 let pins = %01101000 poke $05,%00000000 pause 1 let pins = %10100010 pause 1 b0 = b0 + 1 loop goto reset endif endif endif ' G - - ' - G - ' - - G let b0 = TopRow ^ %00010000 if b0 < TopRow then 'if it was on let b0 = MidRow ^ %00000100 if b0 < MidRow then let b0 = BotRow ^ %00000001 if b0 < BotRow then 'Matrix the display again let b0 = 0 do while b0 < 100 let pins = %11010000 poke $05,%00000000 pause 1 let pins = %01100100 pause 1 let pins = %10100001 pause 1 b0 = b0 + 1 loop let pins = 0 pause 250 let b0 = 0 do while b0 < 100 let pins = %11010000 pause 1 let pins = %01100100 pause 1 let pins = %10100001 pause 1 b0 = b0 + 1 loop goto reset endif endif endif ' - - R ' - R - ' R - - let b0 = TopRow ^ %00000010 if b0 < TopRow then 'if it was on let b0 = MidRow ^ %00001000 if b0 < MidRow then let b0 = BotRow ^ %00100000 if b0 < BotRow then 'Matrix the display again let b0 = 0 do while b0 < 100 let pins = %11000010 poke $05,%00000000 pause 1 let pins = %01101000 pause 1 let pins = %10100000 poke $05,%00001000 pause 1 b0 = b0 + 1 loop let pins = 0 poke $05,%00000000 pause 250 let b0 = 0 do while b0 < 100 let pins = %11000010 poke $05,%00000000 pause 1 let pins = %01101000 pause 1 let pins = %10100000 poke $05,%00001000 pause 1 b0 = b0 + 1 loop goto reset endif endif endif ' - - G ' - G - ' G - - let b0 = TopRow ^ %00000001 if b0 < TopRow then 'if it was on let b0 = MidRow ^ %00000100 if b0 < MidRow then let b0 = BotRow ^ %00010000 if b0 < BotRow then 'Matrix the display again let b0 = 0 do while b0 < 100 let pins = %11000001 poke $05,%00000000 pause 1 let pins = %01100100 pause 1 let pins = %10110000 pause 1 b0 = b0 + 1 loop let pins = 0 pause 250 let b0 = 0 do while b0 < 100 let pins = %11000001 poke $05,%00000000 pause 1 let pins = %01100100 pause 1 let pins = %10110000 pause 1 b0 = b0 + 1 loop goto reset endif endif endif 'Is the board full? let b0 = BotRow ^ %00100000 'R3 if b0 > BotRow then let b0 = BotRow ^ %00010000 'G3 if b0 > BotRow then goto draw1 'Here, both must be off, so leave. endif let b0 = BotRow ^ %00001000 if b0 > BotRow then let b0 = BotRow ^ %00000100 if b0 > BotRow then goto draw1 endif let b0 = BotRow ^ %00000010 if b0 > BotRow then let b0 = BotRow ^ %00000001 if b0 > BotRow then goto draw1 endif 'So now at least one of each light on the bottom row is on. Repeat... let b0 = MidRow ^ %00100000 if b0 > MidRow then let b0 = MidRow ^ %00010000 if b0 > MidRow then goto draw1 endif let b0 = MidRow ^ %00001000 if b0 > MidRow then let b0 = MidRow ^ %00000100 if b0 > MidRow then goto draw1 endif let b0 = MidRow ^ %00000010 if b0 > MidRow then let b0 = MidRow ^ %00000001 if b0 > MidRow then goto draw1 endif let b0 = TopRow ^ %00100000 if b0 > TopRow then let b0 = TopRow ^ %00010000 if b0 > TopRow then goto draw1 endif let b0 = TopRow ^ %00001000 if b0 > TopRow then let b0 = TopRow ^ %00000100 if b0 > TopRow then goto draw1 endif let b0 = TopRow ^ %00000010 if b0 > TopRow then let b0 = TopRow ^ %00000001 if b0 > TopRow then goto draw1 endif 'So all the lights are on - show a sequence and end. let pins = %00011111 poke $05,%00001000 pause 500 reset: let pins = 0 poke $05,%00000000 let TopRow = 0 let MidRow = 0 let BotRow = 0 let b0 = 0 let b13 = 0 goto tictac