PIO explained PICOMITE

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Joined: 11/02/2018
Location: Australia
Posts: 1368
Posted: 06:28am 15 Dec 2022      

For #2 this is all I can manage. It works after a fashion but the phase shift is a little over 180 deg.
SetPin gp0,pio1
SetPin gp1,pio1

p0=Pio(pinctrl 0,1,,,,gp0,)
p1=Pio(pinctrl 0,1,,,,gp1,)

f=2000 * 5.4 'Hz for 2700Hz out.

'pio program
'line   code  comment
' 0     E081  GP0 output
' 1     E101  pin high, dly=1
' 2     E000  pin low
' 3     0001  jmp 1

'program pio1
PIO program line 1,0,&he081
PIO program line 1,1,&he100
PIO program line 1,2,&he001
PIO program line 1,3,&h0001

'write the configuration
PIO init machine 1,0,f,p0,,,0
PIO init machine 1,1,f,p1,,,0

'start the pio1 code
PIO start 1,0
Do While Pin(gp0) : Loop
PIO start 1,1

'Check the frequency in MMBasic
SetPin GP6,FIN
 Pause 1000
 Print Pin(gp6);" Hz at GP6"


All attempts to invert the output within the PIO program failed.