how to use the trrs video output?

laurent974 · 2016-03-16 15:16

Hello,

i'm discovering the brave new world of MCU, sorry for the newbie question.

The last activity board (https://www.parallax.com/product/32912) has no VGA output but it comes with a trrs audio/video.

can i plug that to a PC monitor with RCA input ?

Anyone has a code that use this trrs video output ? Or do the example code that use the VGA still work?

kwinn · 2016-03-16 15:45

That connection could be made to work with a monitor that accepts composite video. You would have to build the circuit to create the composite signal from the prop video pins and split the cable from the trrs jack into separate rca connectors for audio/video at the monitor end.

laurent974 · 2016-03-18 22:04

I'm sorry but that's not clear for me.

if i connect a cable from this output to my monitor that accept composite input, can i use this code below?

otherwise is there any circuit example that i can look at?

Note: that discussion should be moved in propeller 1 forum.

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

  BASE_PIN = 27                                  ' 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..."))    ' Di

Publison · 2016-03-19 00:17

Moved as requested.

Publison · 2016-03-19 00:23

Using this schematic:

https://www.parallax.com/sites/default/files/downloads/32100-Propeller-Demo-Board-Schematic-RevG_0.pdf

Insert the resistors from P12, P13, and P14 into P27, P28 and P29, (using the base pin in your code). The fourth resistor is seldom used. (Read note on schematic).

Ariba · 2016-03-19 02:45

You need to build the 3 resistor DAC o the Breadboard and connect the output of the DAC to the Composite-Video Terminal on the little 6pin Header.

Best is to connect the resistors at the P12..P14 pins, because that is the default on most Demos.
You can find TV demos in the 'Propeller Library Demos' folder.

Andy

laurent974 · 2016-03-19 19:50

It works! thank you. I use the resistors that is provided with the active bot : 1k, 470, and 220.

how to use the trrs video output?

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