Update..

Here's my current position using the BaroneOSD sample code here: http://www.elenafrancesco.org/old/arduino/baroneosd/

For some reason, it doesn't display on just one line. No idea why, could it be a PAL/NTSC conflict? Or something else? hmmm...

Texas Instruments Sync Chip Samples

Here are my sample VSync chips. I think the LMH1980 or the LMH1981 are 3.3v which will make them out-of-the-box-suitable for my project.
The LMH1980 is so small I can't pick it up securely in my fingers, so I don't know how I am going to use it in my breadboard prototypes.... Very daunting. 

Samples Update

Just got a confirmation from T.i. Theyre sending me £30 worth of samples   

samples

Just attempted to order a whole bunch of samples from Texas Instruments. They gave me a big f.u. last time. But fingers crossed again. It's really exciting because I found some really cool sync chips.

Progresssss

ooooh under 2g 

It looks good, but I'm a little sceptical about the ability to run on 3.7v as claimed, if only because it's running the MAX7456 which doesn't run on anything under 4.75v as says here: http://datasheets.maximintegrated.com/en/ds/MAX7456.pdf

I nearly got the barone osd circuit going last night. Still some flickering & some guesswork, but almost worked using the demo script. I think the BaroneOSD is the way to go for truly lightweight, 3.7v, and to make yourself at home (diy).

It looks like more & more people are looking into micro-quad osd's which is great news.

Doodled this circuit just earlier. Should be accurate, and as tiny an osd as there will ever be:

update

There's also this that is interesting me: 


£12 from here

- 10DOF modules (three-axis gyroscope + triaxial accelerometer and three-axis magnetic field + atmospheric pressure) 
- Chip: MPU6050 + HMC5883L + BMP180 
- Power supply :3-5v 
- Means of communication: IIC communication protocol (fully compatible with 3-5v system containing LLC circuit) 
- Size: 2.2cm * 1.7cm

It would mean the possibility of having an artificial horizon 




Using the 5v booster idea, there's also this (more costly) possibilty of SimpleOSD:



SimpleOSD = £25 (plus import tax & postage) (£40)
Booster = £1
BMP180 = £2
= £43

More costly, but 4g in weight (as opposed to 8g & £13 of the Minimosd)

benbojanglesosd update

So, here is my progress in my benbojanglesosd experiment.





I'm finding it quite demanding, but I'm making advances. For someone who has never made an electronic circuit before, I'm not doing too badly 

Anyway, I have learned now, that there are stages/sections to this circuit.
-The Arduino: prints screen text
-LM1881 part: syncs/strips vsync data (somehow. I'm not fully understanding of it yet)
-Camera: displays screen video

I am not sure yet if the LM1881 is supposed to V-sync arduino data, camera picture, or both????? 
I learned, that if I just connect the arduino signal + camera video using a composite splitter adapter into the monitor, the picture is very very flickery.

So I guess that the LM1881 removes either one or both signal's vsync to allow both to merge. But I still don't get this part, or how to link the LM1881 correctly. 

It honestly feels like learning a foreign language sometimes, or how I imagine people with dyslexia feel when trying to understand data. I think, as I usually do, that the project isn't fully understood by my brain properly yet - because it's not been laid-out in a way that my brain can understand it yet. Ugh!

Anyway, here's the video of it so far:

Update..

Hugely impressed with the OSDongs progress. Such fluidity: 

OSDongs first test (0 min 18 sec)

But not for our ghetto v929 quad   

OSD thoughts...

So, thinking about my plans for the lightweight 3.7v OSD...

I have been looking at the lowest possible cost with relation to simplicity & acheiving my goal of displaying altitude & time counter. Anyway, I came across the minimosd



It is already integrated with Arduino Atmega328p & MAX7456 (another chip that will overlay data like the LM1881 chip) and it can be bought for £10 here

To use this board with the V929, one must increase the voltage from the 1s 3.7v lipo to 5v. To do this we could use a £1 5v booster like this: 


Then, we could solder the BMP180 to the minimOSD and make an osd like this:


Cost should be around £13 (minimosd = £10, booster = £1, BMP180 =£2)
Weight should be around 8g

It is an option...

BenbojanglesOSD

I am mostly atempting to use 3.3v as follows:
-My micro quad is 3.7v using 1s lipo batteries.
-BMP180 is 3.3v
-I have an Arduino pro mini 8mhz 3.3v
-I really like the small size of micro quads, I feel they are not threatening to people around me (it's sub 100g)

The more time I spend thinking about problems, I find different ideas for possible solutions:

-Use a small 2s 7.4v lipo 
-Use a 3.3v regulator to supply the flight controller
-This will probably be too much weight to fly (including fpv camera & tx)

-Use a 5v booster for an Arduino pro mini 16mhz 5v or SimpleOSD
-Increase in weight
-How much reduction in fpv time? (3.7v battery supplies: camera, vtx - video time as is = 1hour)
-Can the BMP180 be used with the SimpleOSD?

In my head, the perfect solution will be:
- 3.7v BenbojanglesOSD that includes BMP180 & Video Sync on board
-the 8mhz or the Arduino 3.3v is not a problem for the BMP180, it works fast enough
-It will be lightest possble weight
- I contacted texas instruments to ask them if they make a video sync separator chip that is 3.3v.
- Still waiting for reply.
- There is also a company called Intersil that make vss chips. here is a list (I am still trying to figure out the different chips, and what they do) Link here


I would be very interested in the video sync without LM1881 chip. I looked on the internet for ideas and tutorials, but could not find anything that offered an accurate tutorial. The main places I found included: here and here (but the link is down)

Progress..

hmmmmmm.... Seems the LM1881 uses a minimum of 5v, so says in it's spec sheet. I will try, if not useable, seek alternative. Always alternatives   

Anyways, here is a video of my progress:

BenbojanglesOSD video1 (0 min 53 sec)

  

BenbojanglesOSD v0.2 Update

Hello 

I am making progress with this project 

I have programmed the Atmel 328 to output serial data. This data includes altitude, and timer/counter from the moment I press the reset button.

I have connected this to my tablet using a bluetooth module like this one and I can display both the altitude data and timer. I am happy with the data.

I am waiting for the delivery of the LM1881 chip so that I can work on video overlay, hopefully this will arrive within the next few days.

Once I am happy with the video overlay, I can then work on cleaning it up ready to prototype. I am also waiting for an arduino pro 3.3v 8mhz board so I can work on suitable & efficient 3.3v regulation. 

Here is a picture of my setup so far (the bluetooth output circuit)



The serial output can print data out at different rates, I am testing my preference between 8xsec, and 64xsec. It is very much fast enough!

I have also experimented with data smoothing algorithms, however I am not satisfied with my experiements, and find raw altitude data more effective. Right now, I am using no decimal places in the altitude data (eg 245.42m), as I think the accuracy is better with just metres. I feel the sensor, like most barometric sensors, jumps about with a deviation of +/- 0.7m. 

So, in summary, the future is:
-LM1881 sensor overlay
-3.3v regulation
-More experiments with smoothing data
-Prototype

Progress.

So, now I have the altitude data, I need to overlay this data onto video. To do this we use an LM1881 - Video Sync Separator chip like this one:



So, go order one already   

BenbojanglesOSD v0.2

Hello tonight I configured video output to the monitor. It was really embarrassingly simple. 

BenbojanglesOSD V0.2
-configured basic video output circuit
-adjusted text screen position

+make smaller font size
+figure out how to overlay onto camera image

Anyway here are a couple of photos of my efforts:

Progress..

Progress on my circuit idea:

A few doodles  :

Why BMP180.

At present, I have chosen to go with the bmp180 sensor over the ms5611 sensor. I am aware of the very high accuracy of the ms5611. 

My reasons for the bmp180:
- 8x lower price
- already have code for it
- when interfaced with atmega328 3.3v (@8mhz), the bmp180 will run at (3.5mhz). I feel the 20mhz of the ms5611 will not be utilised effectively by the atmega chip, so a little bit pointless?

Maybe in the future, or to use in a flight controller, the ms5611 seems good. For the case of a ghetto-cheap altimeter-osd the bmp180 is ok.

Wiring done - part 1

Hi Guys,

Well, I made progress on my tiny osd build for the v929. As you can see from the pictures the altitude sensor is tiiiiiiiiiiny! I think the OSD will be 2g in weight.

BenbojanglesOSD v0.1
-3.3v
-atmega328 3.3v
-bmp180

+Wired up hardware
+Coded, and have altitude data in serial display

----------------------------------------------------------------------------------------------------------

Now to make video overlay. Advice, comments, and feedback appreciated.   

BenbojanglesOSD - for V929 quad

Hi all, I decided to try to build my own OSD for the v929/v212 or any micro-quadcopter with 3.7v.

I want: 
-light as possible
-Altitude display
-timer from liftoff
-(possibly) voltage sensor

I think for weight saving, I will be using a barometric pressure sensor to measure altitude as opposed to gps. Of course, gps will be too heavy, and requiring too much voltage.