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Old Jan 20, 2013, 01:51 PM
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United States, AZ, Gilbert
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Originally Posted by Ascended View Post
Todo:
* Check that the BMP085's I2C lines are 5V tolerant.
Technically they can work with 5v signaling, but it will burn out if it gets 5v from the Atmega's internal pullups. Of course those can be turned off, but I would add a level shifter, either resistor dividers or something cheap like a PCA9306.

Its a really good looking board, good work.
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Old Jan 20, 2013, 02:04 PM
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Latvia, Riga
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From experience with MultiWii and IMUs it uses all of them have pullups to 3.3v and Arduino pullups disabled.
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Old Jan 20, 2013, 02:47 PM
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That sounds good. I look forward to testing it. Thank you.

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Originally Posted by Dennis Frie View Post
Thanks!
By the way, you'll get one soldered and ready to install in a plane and the other one ready for your soldering-iron. That should give you a reference and an OSD that can get airborne quickly
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Old Jan 20, 2013, 04:45 PM
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United States, AZ, Prescott Valley
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Originally Posted by Dennis Frie View Post
In theory, you should be able to use 1-4 for control, 5 for Naza and 6, 7 or 8 for PPM. If you put RSSI and link on channel 9 and 10, you still have channel 7 and 8 for control. But I gotta admit, that I haven't tested the 12-channel PPM-output myself, as I don't get anywhere near the channel-limitation.
Yes, thanks Dennis.....that makes sense.
I'll give it a try
Rick
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Old Jan 20, 2013, 05:27 PM
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Ah I see there is a lot of good progress. Does anyone intend to sell just the hardware?
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Old Jan 20, 2013, 05:32 PM
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Denmark, Capital Region of Denmark, Naerum
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Ah I see there is a lot of good progress. Does anyone intend to sell just the hardware?
Yup, it should be an acceptable software and hardware version at the moment. Will update a few things for better customization, negative temperature etc. but except for that we just need some testing.

I don't think anyone sells the hardware, but everything is available and everyone can feel free to sell the hardware if they want to.
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Old Jan 20, 2013, 06:00 PM
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Quote:
Originally Posted by Legot View Post
Technically they can work with 5v signaling, but it will burn out if it gets 5v from the Atmega's internal pullups. Of course those can be turned off, but I would add a level shifter, either resistor dividers or something cheap like a PCA9306.

Its a really good looking board, good work.
Quote:
Originally Posted by kristaps_r View Post
From experience with MultiWii and IMUs it uses all of them have pullups to 3.3v and Arduino pullups disabled.
Thanks, most things i'm working on are 1.2v, 1.8v or 3.3v. We rarely see anything 5V these days! I'll add in some level shifting.

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Originally Posted by flyandi View Post
Ah I see there is a lot of good progress. Does anyone intend to sell just the hardware?
If anyone is interested in my version, I'll get some boards made.
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Old Jan 20, 2013, 06:04 PM
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Originally Posted by Dennis Frie View Post
Looks good
Great to see you got something out of the schematic, even though it wasn't exactly done .

I can see that you have mounted decoupling-caps on MAX7456. As far as I can see, MAX7456 have internal load-capacitors for the crystal. I also had them mounted on the first versions, but it works just fine without.

The 5-volt regulator is not a bad idea, but I think it will get quite hot with 6S li-po.

I tested a version with 5-volt regulator, but decided not to go with that solution, as it got too hot for my taste.

But in general it looks very good .
The extra EEPROM is a nice feature. I have a few different I2C EEPROMS laying around for testing, but been busy with other things lately.
I ended up only using your schematic for what connects to which pin of the IC - and even thin kinda ignored it as I added a bunch of stuff

Hmm, I didnt see anything in the datasheet for the MAX not needing caps on the osc.

The heat is really going to depend on the current draw of the MAX, the atmega, baro and GPS wont use enough power to cause any heating. The current sensor from 3DR has a vreg on it (a TI board) so that can also be used for input if you dont mind bypassing the filtering.
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Old Jan 20, 2013, 07:55 PM
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United States, AZ, Gilbert
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The 7456 has capacitors onboard for the crystal. Its on page 42 under "Selecting a Clock Crystal."
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Old Jan 20, 2013, 08:00 PM
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Originally Posted by Legot View Post
The 7456 has capacitors onboard for the crystal. Its on page 42 under "Selecting a Clock Crystal."
Hah, I missed that - thanks.
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Old Jan 21, 2013, 06:15 PM
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i got all the items in to build this with an arduino nano & sparkfun max7456, bmp085 and the gyro board (all specified through this thread)

i was running this on the test bench with version 8, and all seemed stable ... upgraded to version 10 and after a short random period, maybe 2 mins ish, the bmp altitude goes mental scaling up & down to the max limits, the altitude numbers next to the bar shows random characters & letters then the arduino hangs and needs to be reset.

any ideas where to start ? what other info is needed to debug ?
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Old Jan 21, 2013, 07:27 PM
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United States, AZ, Prescott Valley
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Originally Posted by Tang0au View Post
i got all the items in to build this with an arduino nano & sparkfun max7456, bmp085 and the gyro board (all specified through this thread)

i was running this on the test bench with version 8, and all seemed stable ... upgraded to version 10 and after a short random period, maybe 2 mins ish, the bmp altitude goes mental scaling up & down to the max limits, the altitude numbers next to the bar shows random characters & letters then the arduino hangs and needs to be reset.

any ideas where to start ? what other info is needed to debug ?
Hi TangOau,

I think I know where to start .... well actually where to go back
Try disconnecting the gyro and all should be good. At least my Nano version works fine without the gyro.
Dennis has not finished the code for the gyro yet. I think if you back a few posts you will see that discussion.

Hopefully that helps,

Rick
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Old Jan 21, 2013, 07:30 PM
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thanks - will give it a go ...
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Old Jan 22, 2013, 08:38 AM
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So, I've added the level shifter which actually helps cleanup the routing which is nice.

I'm also hooking up HSYNC/VSYNC/LOS to the uC. LOS will allow internal sync gen to be turned on if something happens to the camera.

I'd really like to get gps coords telemetried down to the ground on video overlay in the VBI, so i'm going to use HSYNC/VSYNC for that. Need to double check that the MAX will generate the same syncs as you'd expect from a sync separator, a quick look at the datasheet makes me feel as though it does. I'll have to check in depth however.

Having VSync hooked up and on an interrupt also allows the OSD data to be transferred during the VBI, which will prevent any corruptions in the display.

This leaves 1 pin free on the uC.
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Old Jan 22, 2013, 10:56 AM
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If you start working some video-telemetry, be sure to post code here...And regarding the ground-station solution hope you go with some generic arduino, not that over-priced Ardustation.
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