Problem connecting my Propeller PE Board to the NTSC RCA plug

edlikestoboogie

I just bought the PE kit and did the first lab.. setting everything up.
I assembled the kit on the breadboards, and then
I got the blinking LED test program to work, but then when I did the second one,
the one where you press a push button to slow the rate of the blinking LED it didn't work.
The LED would keep blinking, but when I pressed the push button it didn't slow down. I double
checked the wiring, it was done properly..

So now I moved on to the propeller manual..
I am extremely eager to get the NTSC display output running.
So I check out the schematic on page 90 of the manual.

The 560 ohm, 270 ohm, and 1.1k ohm resistors are kind of rare.
But I was able to find both the 560 ohm and 270 ohm resistors at radioshack.
And the 1.1k I had lying around.
Only thing is that they are all 1/2 watt resistors instead of 1/4 watt.. Does this matter?
I don't think so.
I soldered all the resistors to the center ring of a RCA plug. and then the
1.1k resistor to pin 12.
560 resistor to pin 13.
270 resistor to pin 14.

I soldered the outer ring of the RCA plug to a wire. and plugged the wire to the black
power strip of the bread board from the PE kit.

I tried running the TV_Text_demo and the TV_Terminal_demo.. and I copied and pasted the program on
page 139 of the manual.

None of them displayed anything. I don't know what to do? Can anybody help?

Graham Stabler

I think it would be worth getting the led demo to work before moving on, there could be some other issue. Perhaps you could post a picture of it wired up.

1/2W just means they can dissipate even more power than 1/4W so it is not a problem.

One guess is that perhaps you have not added all of the wires required to make the black power strips actually connected to negative. They are in two halves and need a jumper between.

Graham

ThePenguinMaster

actually i dont believe the ground on the rca jack is really critical. i believe its just to shield any interference down the wire.is the screen comming up black, blue or anything? or is absolutally nothing happening? i understand why you want to get the tv text out working.. it makes for a good way to debug some of the other projects. but if your not getting any fuzz or anything on the tv maybe theres a programming problem.

ThePenguinMaster

oh, and what about pin 15? i think you missed one.

Graham Stabler

You need the grounds to be referenced one way or another otherwise the signal could be at any voltage relative to the TV ground, in some systems this might happen anyway by the supply but perhaps not this one. The 4th resistor is not a requirement.

Graham