Schmart Board and RCA

nedfrank

I bought a Schmart board at Defcon and put it together. Things seem to be working ok, but I'm having problems outputing to a TV via an RCA jack. I've added the resistors the way it's specified here http://www.parallax.com/Portals/0/Downloads/docs/prod/edu/28050-RCA-Adapter-v1.0.pdf and connected to pins 12-14. All I get on the screen when I run the sample code is a black screen with a flash every once in a while, no text. Here is the sample code

''File: Test TV Text.spin
''Tests baseband video connection by displaying text message on TV

''See 28050-RCA-Adapter.pdf for schematics and instructions.

CON

_clkmode = xtal1 + pll16x ' System clock settings
_xinfreq = 5_000_000

BASE_PIN = 12 ' DAC base pin is P12

OBJ

tv : "tv_terminal" ' Declare tv_terminal object

PUB start | i

tv.start(BASE_PIN) ' DAC base pin is P12
tv.str(string("This is a test message...")) ' Display message

The weird thing is that when I load it in Gear with the TV plugin I get the same results. I've tested continuity to the pins and everything looks good. Any ideas?

Thanks,
Dave King

nedfrank

Figured it out, I was using the wrong resisters (I was using K Ohm for all of them, not just the first one). Now it works like a champ.

W9GFO

Glad you got it figured out.

I just put my Schmart board together today, I got it at UPEW. I used all surface mount components. There was no indication in the directions as to how to put in that itty bitty LED, I got lucky and put it in the right way around first time. It's a nice little board. I think it would be a lot better if the silkscreen included pin numbers, and some directions for the passive SMT parts would be nice.

Rich H

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The Servo Boss, a 12 channel servo tester kit from Gadget Gangster.