Espritmodel.com Telemetry Radio
msev's blog
Posted by msev | Mar 13, 2012 @ 11:05 AM | 6,727 Views
I plan on first building it on the breadboard and later put it on a pcb. I don't plan to add any sma connectors I would just like to connect the antennas directly, so I'll later ask you for reference where I should connect the inner conductor and where the outer shielding of the coax.

I'm thinking of making two same boards, since the receiver can also be the transmitter.

I plan on using an atmega328 dip with uno bootloader from ebay. (http://www.ebay.com/itm/1x-ATMEGA328...item4ab4b4ab58)

Here is the schematic for the OpenLRS receiver: http://www.flytron.com/pdf/OpenLRS_RX2.pdf

So on to the questions, am I understanding correct that the atmega328 is running at 16MHz at 3.3V...Because 3.3V is needed for normal operation of the rfm22, any more voltage (within its tolerances) and it will burn..
So basically he is overclocking it a bit right..But I've read its ok, that the chip takes it fine at ambient temps.

Next thing, I see a 3.3V regulator on the schematic,...this is used that the user can input a higher voltage battery to the system,...So this 3.3V is feeded to the chip right? And also to power some 3.3V sensors if I should add them..

For programming I should use a 3.3V ftdi basic breakout board right?

What does that connection from PC6 on atmega to dtr do? (is it for autoreset when uploading sketch to arduino?)

Where should that cap (C3) between GND and VCC do?

The connections on the right side of rfm22b on the schematic are a bit confusing?
Posted by msev | Jan 14, 2012 @ 03:52 AM | 6,424 Views
Hi,

well here is the thread about Dennis Frie's excellent diy OSD: http://www.rcgroups.com/forums/showthread.php?t=1473207

Since I'm more or less an electronics noob, I'll ask the guys in the thread to help me out in building it (i have a few questions)...The needed materials I have at home already..I have materials for both versions the lm1881 one and the pot one, I'll first try with the lm1881 version..

Now let's start with the noob questions.

So basically I can see the video ground being connected to the osd (is this also needed if the cam has it's own battery? Like my bloggie?)..

And the video out cable (yellow connector, is being feed to the circuits, and at the same spot it's being put out (the video signal)...So basically there are three wires connected at that spot. The video out from the cam, the wire from the "circuit" and the wire going to the video tx.. (I believe this is correct I saw a schematics of this also)..

Can I use normal wire (like servo wire) for video out and video in or do I need a coax wire?

Can I use a 5V 3A ubec to power the osd? Or do I need a more sophisticated solution?

I have the flytron gps, do I need to seperatly put power to it or will it be feeded from the osd? Where do I connect the gps, I don't see it on the schematics...

Thanks for the help!