My goal is to overlay data from NRF24L01+ to my TV's PAL/NTSC signal.
How would one wire LM1881 chip to an Arduino Nano so that output from the Nano would be overlaid to the TV box's signal?
That chip is a sync separator.
It extracts sync pulses from an EXISTING video signal.
Leo..
There are two existing signals. I am asking this because this is the chip Video Experimenter Shield uses to create a overlay but I do not know how this should be wired up when separated.
An overlay is something you put on top of an existing video signal.
Give us more info/links.
Leo..
Avamander:
...output from the Nano would be overlaid to the TV box's...
Video Experimenter Shield is for Uno. I have a Nano and I wish to overlay data to my TV box's signal that means I wish to replicate some of that shield's functions. They use LM1881 to overlay and I want to use the same chip but without those extra features the shield offers. Am I clear enough now?
Yes, all clear now.
The eagle files (schematic) are on that website.
Should be easy to replicate on a piece of veroboard.
The chip does NOT create or add the overlay.
It's a sync pulse extracter. A timing IC.
It tells the Arduino WHEN to insert text.
The Arduino inserts the actual text with resistors and diodes (D1, R2).
Leo..
Wawa:
Yes, all clear now.The eagle files (schematic) are on that website.
Should be easy to replicate on a piece of veroboard.The chip does NOT create or add the overlay.
It's a sync pulse extracter. A timing IC.
It tells the Arduino WHEN to insert text.
The Arduino inserts the actual text with resistors and diodes (D1, R2).
Leo..
I knew that. I did try to modify the schematics to exclude unnecessary components but there were a few I had no idea of what they do. (See the area around switces and pots in the eagle files) I just wanted a really simple schematic with only overlay (timing) function but I was unable to create one.
You just have to work out what switch positions and jumpers you need, by reading the instructions.
And then see what you can/can't remove.
I think the switch is drawn in the "overlay" position.
Do you have video "through" (in to out).
Leo..
Wawa:
You just have to work out what switch positions and jumpers you need, by reading the instructions.
And then see what you can/can't remove.
I think the switch is drawn in the "overlay" position.
Do you have video "through" (in to out).
Leo..
Is this all okay? Will this work?
You can offload all the heavy processing from the arduino and use this chip - it's specially made for the purpose of OSD.
// Per.
Zapro:
You can offload all the heavy processing from the arduino and use this chip - it's specially made for the purpose of OSD.// Per.
It's SMD, requires SPI (already occupied by radio) and a "bit" pricey for a beginner.
(Altho if someone would tell me how would I be able to use NRF24L01+ alongside with this I'd even look into using this)
Avamander:
It's SMD, requires SPI (already occupied by radio) and a "bit" pricey for a beginner.(Altho if someone would tell me how would I be able to use NRF24L01+ alongside with this I'd even look into using this)
It can be done quite cheap, and you get an extra micro (co-processor for OSD, etc) eBay
It seems very tempting but bit pricey. If someone could verify the validity of the schematics I posted that would be great.
Reset button is not needed, unless your shield is going to cover Arduino's reset button.
Pin3 of the LM1881 does not connect to pin 2 of the LM1881, but to shield D2.
I think Diode D2 has to be a wire. D2 is not used in "overlay".
Better try this first on a breadboard.
Leo..
Wawa:
Reset button is not needed, unless your shield is going to cover Arduino's reset button.Pin3 of the LM1881 does not connect to pin 2 of the LM1881, but to shield D2.
I think Diode D2 has to be a wire. D2 is not used in "overlay".
Better try this first on a breadboard.
Leo..
Is it right now?
I will most certainly try this first on a breadboard.
Looks ok now, except for the missing pot on A2.
I don't know if it's needed.
I assume you have read the whole article.
Leo..
Wawa:
Looks ok now, except for the missing pot on A2.
I don't know if it's needed.
I assume you have read the whole article.
Leo..
Many thanks, I now know exactly what to buy.