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Mr.RC-Cam

Maxim's Loss-of-Video-Sync Alarm IC

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As noted above, I recieved my beta 2 unit last Tuesday.

First, the tale of the boxes. I had not ordered the specified box in anticipation of the arrival of Oracle. In retrospect, I probably should have, but I was thinking it probably a little environmentally insensitive to bring a cheap plastic box half way round the world by airmail. Ok apart form that I was probably procrastinating, :-)

anyway once I had Oracle in my hot little hands, I was too impatient to wait a week for a box, so I went off to the local electronics suppliers looking for boxes. Couldn't find any exact matches, but settled on a jiffy box from Jaycar as a likely prospect. CAT. NO. HB6012 <www.jaycar.com.au>. I had reservations however, because it did not have removable front and back panels. This was going to make it more difficult to install the PCB.

By Saturday I had second thoughts and decided to again chase the specified box. I was surprised to find that one of the suppliers listed in the manual had a dot com dot au suffix to its url. On further investigation I found their Sydney warehouse is only 5 minutes drive away. Not only that, but they are open Satureday! My lucky day. I phoned to place an order only to be told they only stock it in the US and there is a 5-8 day delivery time. :-( Back to the jiffy box.

Still, thanks to Lupy's templates, which were a great help, :rolleyes: (thanks) I had the PCB securely tucked away in the jiffy box, attached by the 4 pcb mounting holes and the 5 RCA screws after about 2 hours work in the shed. Not quite as neat as Lupy's but reasonably workman-like. I had to cut a slot for the progamming switch and move the LEDs back to the edge of the board so it could rotate into position.

As soon as I had the box all closed up I realised that I had not left a hole for access to the brightness trim pot. I might try estimating where it is and drilling a hole without dismantling everything. I don't imagine the self tappers supporting the RCA connectors will stand for too many cycles. Maybe this deserves a mention in the manual or drilling templates? I suppose most will set this and forget it, but some will change gear regularly and require access.

Next the tale of the programming. It looks a little daunting in the manual and feels that way the first time through. Second time "Ok - I'm getting the hang of this!" Third time - "No Worries." In other words, for the target audience it works well. We seem to have some slight mixing of nomenclature - video 1 and 2 verses video left and right that we should discuss, agree on and clarify. Given that we may need to swap sources to adjust the brightness, perhaps 1 and 2 are safer than left and right. Then again L and R are more descriptive. Thoughts?

Well, now to the testing. It had been my intention to purchase a second BWAV diversity unit and try using the Oracle to join them to create a 4 antenna array, however it appears they are out of stock, so the wind has gone from my sails on that idea for the time being. I'll probably come back to that as I have high hopes for it as a great solution, especially after viewing twinturbostang's comparison video. Then again, perhaps 3 Oracles ganged together would be even better! ;) Guess I'll just start using it and see what brain storms arise.

If anyone has any ideas for a brilliant test let me know!

Mr RC Cam thanks for the chance to play with your creation!

Cheers!

B.

post-6-1177754392_thumb.jpg

Edited by boris

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Just an idea - for test purposes we could show when switching occurs by deliberately mal - adjusting the brightness.

Mark - Thanks for the suggestion. I was thinking along the lines of something more controlled and repeatable in the first instance.

Cheers

B.

Edited by boris

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Given that we may need to swap sources to adjust the brightness, perhaps 1 and 2 are safer than left and right. Then again L and R are more descriptive. Thoughts?

Production models will be labeled as Video 1 and Video 2 rather than Video left and Video right. This is a very clear way to reference the two video sources. But, if you want your custom box to be labeled another way then just go for it.

Just an idea - for test purposes we could show when switching occurs by deliberately mal - adjusting the brightness.

Someone mentioned a couple posts earlier that they were going to use the audio channels to indicate which source was in-use. That way the video remains nice looking.

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Production models will be labeled as Video 1 and Video 2 rather than Video left and Video right. This is a very clear way to reference the two video sources. But, if you want your custom box to be labeled another way then just go for it.

I agree this is the best way, and I regret not using your Vid A out and Vid B out for may labels. It was well thought through.

Perhaps the pic below will explain what I was on about.

Hope I was not being too pedantic.

It is just a detail.

Cheers

B.

post-6-1177796431_thumb.jpg

Edited by boris

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I'm not sure, but I think we are saying the same thing. The Video 1 and Audio 1 are for one A/V source, and the Video 2 and Audio 2 are for the other A/V source. The audio left/right inputs are supporting stereo audio (mono apps would just use one of the inputs, usually the right channel, but it does not matter).

Since there are two video outputs, one is labeled as Vid Out-A and the other Out-B. These are not at all assigned to input 1 or input 2, they are just identical buffered video outputs. To help assert that they are not related to the inputs, I avoided calling them Vid Out-1 or Out-2.

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Just got back from flying the version 1.3 chip. I was not flying under the hood, so it was a little hard to see exactly what was going on. I haven't had a chance to review the tape yet.

I flew with the factory settings which were a level 3 sensitivity.

For the most part, the switching seemed pretty clean, with no breakup visible on the lcd screen.

I did notice that it wants to stay with the left or lower video input. I positioned the antennas towards the left and right, and when I flew to the left, it was pretty quiet, with just a couple of chirps. When I went to the right, the chirps were almost constant, and some noise was getting through. I thought it was my antenna or rx, so I reversed the inputs, and the situation was the same, the lower input was the prefered one, even when hooked up to the other rx. so the rx's and antennas were not the cause.

I will try flying with different sensitivities, and see if the situation changes.

interestingly, I was unable to duplicate the situation on the bench. I think that when the signal is mostly clear, then it switches and stays there, but when there are a few errors all the time, then it wants to stay with the lower input. It's almost like it's more tolerant of errors on the lower input.

When I made the back layout, I was orig going to use vid input A and B, but then that would have required a mark on the front as to which light was A and which was B. Usually, the antennas will be placed with one on the left, and one on the right. As long as everything is setup properly, it's easy to see by the lights if one antenna isn't getting much use, and adjust it. If the back is labled A and B, it's easy to make a mistake with the tangel of wires and have the left light indicating the rx on the right. Also, If you use A and B, then if the left light is A, to read from left to right A-B, then the back will be labled with B on top and A underneath.

Now I'm totally confused. ;-)

Of course it's really a mater of personal prefrence and what is easy for setup.

I also got a surprise in the mail today, my long lost 1.2 chip arrived. Here is a pic of the package. It looks like it stuck on a roller and a lot of the lable was removed. It must have been there for quite some time, as it's been in transit for ~2 weeks.

Mr RCcam, do you think it's worth it to try the old chip to see if it has the same prefrence for the lower input?

Ken

post-6-1177817984_thumb.jpg

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Wow, the lost chip's mailer looks nasty. I'm would expect it to be fine, so just send it back to me when you get a chance.

In regards to your observation, the Video-1 seems to be favored when both inputs have good video at the same time. That is because the video signal is tested in order, Video 1, then Video 2. So, Video 1 ends up with a slight bias. For sure, if Video-1 is corrupt then Video-2 will be used.

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I finally got a chance to fly my beta Oracle today. This was my first FPV flight with my Easystar since late last fall, and my unfamiliarity with my setup, compounded with the new equipment, meant that it took a long time at the field setting everything up.

I used the recommended enclosure, and the mounting instructions and template provided by Lupy. Everything lined up perfectly. To make the power connections to the receivers easiest, I added a pair of receptacles on the back of the Oracle, soldered to the back of the existing power input.

While not very difficult to add these receptacles, I would have preferred to see either another pair of existing power connectors, or at least solder points on the PCB to attach to. With Oracles wide voltage operating range and voltage monitoring function; it only makes sense to run the power for the video receivers from Oracle.

As Boris mentioned, it took a few runs thru the programming to get the hang of it. I was expecting programming similar to Castle Creations ESCs, and the way Oracle automatically advances to the next programming step while I was still trying to interpret and analyze the previous one was a bit frustrating at first.

My receivers were an identical pair of the new style of Lawmates from Range Video. I originally had a mis-matched pair of old and new styles, but decided it was best to keep the variables down by having matching units. This also meant I could keep my old ground station intact, and let spectators use its outputs in the future.

The antennae I currently use are Hypertechlink 14db and 8db patches from their http://www.sharperconcepts.net outlet. I mounted the RXs with double-sided tape to the back of the patches, and orientated them with about 3 feet apart, facing out about 20 degrees from parallel and about 2 feet off the ground.

I didn't change the video switching sensitivity, and in-flight performance was amazing, and a huge improvement from my single RX experiences. I heard the Oracle beep as it switched, and I could even predict when it should, based on the aircraft's position and what I knew of the antennas coverage patterns. As I flew towards the edges of my antenna's beam width, towards the vertical plane of coverage, Oracle beeped more frequently. The technique of interpreting this as a warning to turn and improve my exposure seemed to work very well.

For me, the acid test was how my Aiptek PVR worked. Previously, any more then the slightest video corruption would cause the recorder to stop recording, and abandon the current recording file, which required a reformat to recover the space. I don’t expect to ever have that issue happen again with Oracle, provided I stay within antenna coverage.

I’m looking forward to more flights with Oracle to really explore its limits. I’ll be ordering another 14db patch which I feel is the ideal antennae for my intended use, and I’ll also be exploring ways make antenna positioning more optimal and convenient. Thanks to Mr. RC-Cam for providing me with this piece of equipment. I feel it will be a great addition to FPV flyers who want a higher quality signal, without having to invest in higher cost alternatives.

Edited by rob10000

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That is all great news. It is especially nice that the Aiptek PVR plays nice with it. Thanks for the report!

I'm still interested in Oracle's audio switching feature. Will any beta testers be trying it soon (with the Tx's microphone)? I need to establish if the various video receivers will have sufficiently balanced audio levels to eliminate the need for adding audio level pots to Oracle. I've been delaying the production board order just for that reason.

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I've got my box put together, but I probably won't have an opportunity to fly until this coming weekend. Weather permitting I should have some audio/video recorded.

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I'm still interested in Oracle's audio switching feature. Will any beta testers be trying it soon (with the Tx's microphone)? I need to establish if the various video receivers will have sufficiently balanced audio levels to eliminate the need for adding audio level pots to Oracle. I've been delaying the production board order just for that reason.

I can report on that. It didn't dawn on me to give it a second thought. I always record the tx audio, as well as the video, so I didn't think anything of it when I hooked up Oracle.

I like to hear the noises the airplane makes. Hearing the motor change RPM gives me the ability to monitor the battery, and wind noise gives a rough indication of speed, especially when at a high enough altitude that the ground reference doesn't help.

Oracle's performance with video was fine. I didn't detect any changes in audio volume levels, or any other abnormalities when the switch was made to the opposite rx.

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Boris, I could be wrong, but I think that your rear panel labels are incorrect at the Audio Input area. Below is how it should be ID'd (essentially the same as shown in the instruction manual, just fancier looking).

Rob10000, that is very good news!

post-6-1177979426_thumb.jpg

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I need to establish if the various video receivers will have sufficiently balanced audio levels to eliminate the need for adding audio level pots to Oracle. I've been delaying the production board order just for that reason.

Sounds as though time is short. I was hoping to have at least 2 more weekends to come up with some relevant testing. Do you have a timescale in mind?

Boris, I could be wrong, but I think that your rear panel labels are incorrect at the Audio Input area. Below is how it should be ID'd (essentially the same as shown in the instruction manual, just fancier looking).

Before I tear my hair out, are you looking at the picture of my box that I posted 28/4 2:02am or the copy of Lupy's picture of his box that I posted 28/4 1:40pm?

Cheers

B.

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Do you have a timescale in mind?

I need to move forward since I'm over a month behind in where I expected to be at this point. I'll be ordering production fab boards early next week.

... are you looking at the picture of my box that I posted 28/4 2:02am or the copy of Lupy's picture of his box that I posted 28/4 1:40pm?

I was referring to your posted photo shown on Apr 28 2007, 02:40 PM PST. I see now that it is actually Lupy's box that is shown above the Oracle board. Your other posted photo has the correct ID's. Sorry for the confusion.

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Hi everyone,

I also just got the Oracle working. The way I have it setup is a little different than everyone else's, the Oracle's Vid1 input is from a single-antenna BWAV diversity receiver and Vid2 is fed from an airwave 612rx. I wanted to see how much off the video contrast will be if I used 2 unmatched RXs, and to my surprise the video contrasts were very similar and required very little tuning to match them almost perfectly. As far as performance goes, it seems to be on the same level as BWAV diversity...I honestly couldn't tell the difference. My favorite setup right now is using the BWAV Rx with two 14dbi patches in parallel with an airwave 612rx with an Omni... pretty good setup if you want to have it all: 3-way diversity with RSSI and out-of-synch feature :lol:

Edited by bt408

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Well...I won't be able to do a full test of the Oracle this weekend. I made a stupid mistake and fried my 900MHz transmitter. I'm lucky the camera didn't get fried as well.

Long story short: new smaller lipo for the TX/camera setup. Hooked up deans connector. Plugged in deans connector to TX/camera/mic setup and immediately heard a pop. Unplugged immediately, but could already smell the bad news. Looked closely at new battery connector...slap myself in the forehead...wired backwards. :angry:

Luckily the camera and microphone still appear to be working OK, the TX took the hit for the rest of them. I'm just glad I didn't do this on the RX side. I could just see it now...two 900MHz receivers and the Oracle go up in smoke. :o

So, now I have to order a new 900MHz TX. The wife is going to kill me! :P

Relating to the Oracle: I was using it in my basement prior to trying the new battery out and it appeared to be working great. One odd thing with the video level adjustment. It didn't make a huge difference either direction I adjusted it, only slight. If I continued to go either direction very far it started acting like the video was out of sync. Maybe I just needed to flip the video lines and it would have worked OK, it was pretty close anyway. I'll have to wait a week or so to find out.

Edited by Mr.Pibb

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I have just got round to fitting mine in a box and the only problem I found was that the power socket sticks out from the PCB about 2.3mm which make life a bit harder.

Terry

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the only problem I found was that the power socket sticks out from the PCB about 2.3mm which make life a bit harder.

Sorry about that. The power port sticks out so that it is flush with the outside of the rear panel. If you use a tight box that has panels that don't come off then it will really give you a bad time. BTW, the recommended box is a very sweet solution (glove fit).

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I had a look at the recommended box but there is an extra £10 as it is an extended range item.

I didnt want to cut a square hole but maybe I should.

Terry

Edited by Terry

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One odd thing with the video level adjustment. It didn't make a huge difference either direction I adjusted it, only slight. If I continued to go either direction very far it started acting like the video was out of sync.

The affect of Oracle's video adjustment will depend on the viewing device's design. Some utilize video AGC, which can mask things a bit. All that matters is finding an adjustment that looks good on the various things that will be plugged into Oracle's output.

Sorry to hear about the fried hardware. That hurts! Oracle includes reverse battery protection, so that sort of thing won't happen to it.

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Hi All

I used my Oracle for a few hours yesterday.

Unfortunately, I still don't have some the equipment I ordered to help with testing - additional antennae etc, so what I did was to run for a while with the RSSI unit as a baseline, then swap the antenae to the Oracle without moving them and repeat with the tx travelling over the same path. Viewed on that basis it is difficult to make fine level comparisons but both gave good results with some loss of signal when the tx passed behind trees as viewed from the recievers. It was noticable that the Oracle switched more often than the other unit when set at sensitivity 3. Again unfortunately, my normal gear is committed to a big event next week, so I won't be able to do comparison or gang tests the next two weekends, but by the time it is back, I should have the additional new gear.

Mr RC- Cam I'm not sure I can add much value to what the other testers have so ably reported, but I will keep you posted on my progress. I think you have it pretty well right and I'm glad to see above that you are ready to commit to production. Hope it goes well!

Cheers

B.

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Thanks for the status update. Please report your findings when you perform the gang tests.

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Received my replacement TX on Saturday and was able to get a flight in yesterday.

First, results with the diversity system:

Much better than with a single antenna/RX. Areas that had problems, ie takeoffs and landings when using the patch antenna, were much better. Resulted in just a couple chirps of the diversity system and a very small amount of static in the video. I was using a huge scaled up GP Patch antenna (900MHz!) on the ground facing forward tipped back about 45 degrees, and a whip antenna on the RX attached to my camcorder on a tripod.

There were a couple moments where the diversity system beeped a few times in a row quickly. A small amount of static is visible/audible at these points. Multipath is a big problem where I fly. There is a long dam by the field, and the sloped face reflects the signals.

Second: The bad ending of the flight.

I've been using a Spektrum DX6 since last year without a glitch. That fun ended in disaster yesterday. A couple minutes into the flight I had a small glitch. I thought that maybe it was because I was standing so close to the tripod and all the wiring for the diversity system. A couple minutes later a more serious glitch, so I started to head back to land. Then...a third glitch. The plane slowly turned left and nosed down. I think the plane is a total loss. I'm not a "builder" and I'm not sure I can rebuild/repair the damage. Luckily the camera seems to be OK.

I'm not sure what happened. It could have been an actual loss of signal, it could have been a problem caused by the high powered video TX (running at 900MHz not 2.4GHz!), or maybe a loose BEC connector. Regardless I'm concerned about future flights. I've been spoiled up to now, the DX6 has been flawless. Now my confidence isn't very high.

Anyway, here's the video of the flight including the final nose dive. Use the download option on the right for a better quality video (still not as good as the original!).

http://video.google.com/videoplay?docid=-1...084086674&hl=en

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