Chespest FPV + OSD setup
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Chespest FPV + OSD setup
Hi Guys.
Today i got my cheapo FPV + OSD working.
The Video transmitter is the TX5823-101016 off Ebay (200mW, 5.8Ghz).
Displayed characters are a bit shaky, but totally readable.
An external Crystal would improve it, but also add cost.
The antenna i have is a cloverleaf from Hobbyking.
You can make your own cheaper (such as here http://rcexplorer.se/diy/2011/08/the-sk ... v-antenna/)
The Receiver is so simple you can bodge it up on a bit of Veroboard.
I made two - one external, and one that fits in my FatShark Dominator goggles, both on Veroboard.
Schematic & Source code attached.
Unlike some Fake OSD designs i came across on the internet, this works.Not perfect by a long way, but it works.
Enjoy
FFS! extension .ASM not allowed. Renamed to .TXT .
Today i got my cheapo FPV + OSD working.
The Video transmitter is the TX5823-101016 off Ebay (200mW, 5.8Ghz).
Displayed characters are a bit shaky, but totally readable.
An external Crystal would improve it, but also add cost.
The antenna i have is a cloverleaf from Hobbyking.
You can make your own cheaper (such as here http://rcexplorer.se/diy/2011/08/the-sk ... v-antenna/)
The Receiver is so simple you can bodge it up on a bit of Veroboard.
I made two - one external, and one that fits in my FatShark Dominator goggles, both on Veroboard.
Schematic & Source code attached.
Unlike some Fake OSD designs i came across on the internet, this works.Not perfect by a long way, but it works.
Enjoy
FFS! extension .ASM not allowed. Renamed to .TXT .
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- FPV+OSD.txt
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Re: Chespest FPV + OSD setup
doh.
the green blob at the bottom right is an Electret mic.
the green blob at the bottom right is an Electret mic.
Last edited by adrianatkins on Wed May 01, 2013 11:23 pm, edited 1 time in total.
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Re: Chespest FPV + OSD setup
and IC1 is a 3.3v regulator, AMS1117-3.3 in this case, but any 3.3 v regulator will do.
I clearly have not thought this Post out at all
I clearly have not thought this Post out at all
Re: Chespest FPV + OSD setup
You are doing okay.
I noticed that you have used a vintage (very ancient) transistor as the audio amplifier. I haven't seen a 2N706 used in any new designs since around 1970.. I would suggest something slighty more modern like one of the BC series transistors would be a cheaper and better alternative. My favourite type is the BC107. When high gain with low noise is needed the BC109 does the job fairly well. I do know that even they are long in the tooth by modern standards... Showing my age here.
I noticed that you have used a vintage (very ancient) transistor as the audio amplifier. I haven't seen a 2N706 used in any new designs since around 1970.. I would suggest something slighty more modern like one of the BC series transistors would be a cheaper and better alternative. My favourite type is the BC107. When high gain with low noise is needed the BC109 does the job fairly well. I do know that even they are long in the tooth by modern standards... Showing my age here.
Re: Chespest FPV + OSD setup
Any little video/screenshot?
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Re: Chespest FPV + OSD setup
Doh again.
The transistors i used were a 2N3906 on the left and a 2N3904 on the right (the audio amp).
A BC109 A, B or C would work fine as the audio amp (which is completely optional).
I dug out an ancient copy of Eagle to do a 'pretty' schematic, and forgot to change the Label.
That's also why both transistors are labelled 'Q1' !
The transistors i used were a 2N3906 on the left and a 2N3904 on the right (the audio amp).
A BC109 A, B or C would work fine as the audio amp (which is completely optional).
I dug out an ancient copy of Eagle to do a 'pretty' schematic, and forgot to change the Label.
That's also why both transistors are labelled 'Q1' !
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Re: Chespest FPV + OSD setup
The two boards in the photo are the receivers.
The one on the left fits in my FatShark dominator goggles, and works exactly like the 'official' one - even the channel button works normally.
It's showing 13.5V because it's running on my Shed 12v system, not a Lipo.
The code auto-detects whether it's running on 1S, 2S or 3S, and starts flashing 'LOBAT' if the supply drops to 3.3v per cell.
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Re: Cheapest FPV + OSD setup
The Receiver circuit is dead simple :-
http://i669.photobucket.com/albums/vv54/alin_qq/8-9.jpg
FatShark Dominator RX module
pinout - from Top to Bottom :-
CH1
CH2
CH3
Video
Audio R
Audio L(?)
GND
+3v3
+5V
With a Sony CMQ1684L camera, the parts cost me under 70 quid
for a full Camera, sound, TX & RX FPV setup with basic OSD
http://i669.photobucket.com/albums/vv54/alin_qq/8-9.jpg
FatShark Dominator RX module
pinout - from Top to Bottom :-
CH1
CH2
CH3
Video
Audio R
Audio L(?)
GND
+3v3
+5V
With a Sony CMQ1684L camera, the parts cost me under 70 quid
for a full Camera, sound, TX & RX FPV setup with basic OSD
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- Joined: Wed May 01, 2013 8:39 pm
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Re: Chespest FPV + OSD setup
Aw c**p. Obvious really.
The 3v3 regulator will get too hot at 3S, so i'll have to add a buck converter instead.
Please wait for version II - don't build this thing.
The 3v3 regulator will get too hot at 3S, so i'll have to add a buck converter instead.
Please wait for version II - don't build this thing.
Re: Chespest FPV + OSD setup
IF your regulator is decently cooled by a nice ground plane it should be ok, the cased receivers (RC305) use linear regs and do fine on 3s.
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Re: Cheapest FPV + OSD setup
If it gets Hot, then that's wasting battery juice.
I've ordered some bigger 16F1823 chips with 2 comparators in them.
When they arrive i'll remove the AMS1117-3.3 and add a Buck converter instead.
We'll see if that works.
If not, big heatsink !
I've ordered some bigger 16F1823 chips with 2 comparators in them.
When they arrive i'll remove the AMS1117-3.3 and add a Buck converter instead.
We'll see if that works.
If not, big heatsink !
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Re: Chespest FPV + OSD setup
Version 2 is looking better.
i've tried the Buck converter thing and it adds Noise to the video, so decided to drop it in favour of a 3v7 1S battery to run the video transmitter.
Works better.
Sticking with the 16F1823, i used the idea of rotating the TRISC register to do the video output.
This saves a shed load of variable space.
Currently i'm trying to get it to I2C interface to a Compass and a Barometric sensor, so it can display Heading and Altitude as well as the Flight & FPV battery voltages.
I'll post a new thread when version 2 works as required.
i've tried the Buck converter thing and it adds Noise to the video, so decided to drop it in favour of a 3v7 1S battery to run the video transmitter.
Works better.
Sticking with the 16F1823, i used the idea of rotating the TRISC register to do the video output.
This saves a shed load of variable space.
Currently i'm trying to get it to I2C interface to a Compass and a Barometric sensor, so it can display Heading and Altitude as well as the Flight & FPV battery voltages.
I'll post a new thread when version 2 works as required.