graphics demo pin connection

mikea

I'm trying to use the graphics demo. I'm using the professional development board that has 4 resistors going to an rca jack. "Tv" is a child object under the graphics demo, I found the pinout for the jack in the dat section, but i'm not having any luck with the display. How to use the demo is not clear to me, am I missing something? Also I do have the tv set to video 1, which is the jack i'm connected to.
pin3-560
pin2-270
pin1-560
pin0-1.1k

  the broadcast signal nibble is arranged as:
''        bit 3: aural subcarrier (sum 560-ohm resistor into network below)
''        bits 2..0: visual carrier (sum 270/560/1100-ohm resistors to form 75-ohm 1V signal)
''  _______

mikea

Problem solved, i was looking at boards at the parallax site and on the silkscreen of one it said tv pin 12..15. Tried it with graphics demo and it works.

K2

Just for future reference I'm including an answer Ariba posted to a very similar question I had a month ago.

Ariba wrote: »

You find the description of the pin settings in the TV.spin object:

''  tv_pins
''
''    bits 6..4 select pin group:
''      %000: pins 7..0
''      %001: pins 15..8
''      %010: pins 23..16
''      %011: pins 31..24
''      %100: pins 39..32
''      %101: pins 47..40
''      %110: pins 55..48
''      %111: pins 63..56
''
''    bits 3..0 select pin group mode:
''      %0000: %0000_0111    -                    baseband
''      %0001: %0000_0111    -                    broadcast
''      %0010: %0000_1111    -                    baseband + chroma
''      %0011: %0000_1111    -                    broadcast + aural
''      %0100: %0111_0000    broadcast            -
''      %0101: %0111_0000    baseband             -
''      %0110: %1111_0000    broadcast + aural    -
''      %0111: %1111_0000    baseband + chroma    -
''      %1000: %0111_0111    broadcast            baseband
''      %1001: %0111_0111    baseband             broadcast
''      %1010: %0111_1111    broadcast            baseband + chroma
''      %1011: %0111_1111    baseband             broadcast + aural
''      %1100: %1111_0111    broadcast + aural    baseband
''      %1101: %1111_0111    baseband + chroma    broadcast
''      %1110: %1111_1111    broadcast + aural    baseband + chroma
''      %1111: %1111_1111    baseband + chroma    broadcast + aural
''      -----------------------------------------------------------
''            active pins    top nibble           bottom nibble

and yes, it's a bit complicated.
Simplified:
Set the pin group in the upper nibble and the lower nibble to %0000 if you use the lower 4 pins of the pingroup, or %0101 if you use the upper 4 pins of the group.

A possible calculation from the pin number (untested):

  tvparams[2] := pin>>3 << 4 | (pin>>2 & 1) * %0101

Andy

mikea

Thanks Andy