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Old Nov 19, 2012, 01:06 AM
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Originally Posted by PhracturedBlue View Post
So, I've been thinking about what to do with my Devo7. It is really too limited to be worth a Deviation port, so I was thinking of upgrading the screen. It turns out that finding a screen with a backlight that will fit in the chassis isn't so easy, however, I have one of these:
http://www.ebay.com/itm/STM32F103RBT...-/170782669105
The screen can be detached from the back and fits quite well (though I'm not sure if I can make it touch-enabled because the devo7 has a plastic shield over the display window)
Well, after actually doing some research on the board I have, it is completely unsuitable for use in a transmitter. The ports are wired in a way that they cannot be used as gpio, and too many pins are tied up driving the display.

One option would be to use a different board (I got a teensy 3.0 which probably is up to the job), but it means I need to look for an alternate source for the display. It may be possible to use just the display from the board I have, but that would likely make this a one-off, since the costs would start to get prohibitive.

If anyone runs across a backlit LCD module with driver (color or b/w) with ~1.4"x2.5" display area, and a maximum module width of 2.8", let me know (there are lots of them on ebay, but every one I've looked at has a circuit board that is too wide to fit in the devo7 case. It is possible some have a ribbon cable and can be detached from the circuit board, but you can't really tell from the pics.

The ideal would probbaly be to source the module used in the devo10, but I have no idea where to find one.
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Old Nov 19, 2012, 10:53 AM
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Sorry to hear that's not going to work, looked like an interesting low budget project.

On a related theme, has anybody looked into upgrading the 7e a bit? For example would it be relatively easy to add a couple of switches? If it really uses the same main board as the 6s it seems like it ought to be fairly straightforward. And how about installing ball bearings in the gimbals or replacing the gimbals entirely with those from another model with the quad bearings? The price of the 7e is really attractive but only two switches is pretty nearly a deal breaker. It seems like the 7E could be a real giant killer with a 7105 module, Deviation, and a couple of small upgrades, providing it could be done cheaply.
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Old Nov 19, 2012, 01:45 PM
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Lcd quest is tiresome, I was lucky enough to find one for my WK-1001 to er9x that use this board and have the same lcd driver but without ribbon cable as the one in the Flysky th9x. http://www.befr.ebay.be/itm/New-ATME...item20c41de46d

I think the lcd in walkera products are custom made, I couldn't find any information on the ones that come in the WK-2801 and 2602-03( maybe not searching at the right place) and finally after much time just gave it up.

Could you give more information to what type of lcd you're searching (parallel, serial...) ?

I found one 128x64 with back light almost same viewing area as you and width of 70mm (+/-2.8"), but I think the length of 93mm would be to much for the devo 7

These two are ST7920 based, but the length of the display area on the second one is a little more than what you are searching.

http://www.befr.ebay.be/itm/12864-12...item335c76857e



http://www.befr.ebay.be/itm/1PCS-128...item564efa4adc
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Last edited by blackmoon; Nov 19, 2012 at 02:06 PM.
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Old Nov 19, 2012, 01:45 PM
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Any solution for lipo users to calibrate battery voltage?
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Old Nov 19, 2012, 01:50 PM
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Originally Posted by itsmillertime View Post
Any solution for lipo users to calibrate battery voltage?
Can you clarify what problem specifically you are having? in Walkera firware, there is very little you can do. In Deviation, we report actual voltage, which should be accurate regardless ofthe type of battery you have.
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Old Nov 19, 2012, 01:53 PM
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Reads lower that actual. I put in a fully charged life and the tx shows 6.77V.
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Old Nov 19, 2012, 02:07 PM
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Reads lower that actual. I put in a fully charged life and the tx shows 6.77V.
what does a voltmeter show?
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Old Nov 19, 2012, 03:36 PM
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Here you have one of them. It fits just exact on height 4.8 cm, and is a little small on width so it fits fine on the hole of the walkera Devo 7 transmitter. You need to cut the transparent plastic to use the touch capabilities. There are other screens of 2.8'' but all of them have 5.0 cm of height and don't fit in the hole of the transmitter. This is the only one with 4,8 cm and a big colour touch screen. It has a connector that can be soldered, and without PCB to have more space and be capable to be at place without to retire the lateral buttons of the transmitter.

I have not readed the datasheet but it seems to work with a parallel interface of 16 bits, I think should be better with 8 bits to use less GPIOs on the microcontroller, and it works with 2.8 Volts.

http://www.ebay.com/itm/2-5-TFT-Colo...item2eb2aafe78

Here you have some of 2.8''. They fit fine on the width but they measure 5,0 cm on height and don't fit on the hole, you need to cut the transmitter case to fit them.

http://www.ebay.com/itm/2-8-TFT-LCD-...item27ca756c29

http://www.ebay.com/itm/2-8-TFT-Colo...item2eb8410efe

http://www.ebay.com/itm/2-8-Touch-TF...item256e57e8b4
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Old Nov 19, 2012, 04:36 PM
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Originally Posted by Tripert View Post
Here you have one of them. It fits just exact on height 4.8 cm, and is a little small on width so it fits fine on the hole of the walkera Devo 7 transmitter.
I'd probably prefer to use a black&white screen than a color one for a port. the main reason is that a color screen will require more hardware to support which will mean more limitations in the MCU that can drive it. since I'm not going to design a custom circuit board, we want to find off-the shelf development boards that are inexpensive enough and have sufficient performance to meet our needs.
For anything I work on, it'll be ARM based (probably M3) since that is the minimum hardware needed to run Deviation.
Also, it is much more likely that a 128x64 board will have the right aspect ratio for the devo7 than a 320x240 board will.
I have a 2.8" board already (came with the board I mentioned above, that uses a 16 or 8-bit interface). it actually fits in the devo7 (though as you note you can't access the full 240px of height). but you'd need to spend $30 for the screen + ~$20 (or more) for a MCU that can control it, and that makes it too expensive for what you'll end up getting. All of the boards you show require working with a ribbon cable. I am trying to find off-the shelf parts that require a minimum of soldering. If the solution requires soldering a ribbon cable, it is probably out of range of most people who would want to do it.
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Old Nov 20, 2012, 12:42 AM
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I got my Hubsan x4 today. I immediately opened up the Tx, and grabbed some captures.
The protocol looks pretty straight-forward:
1) The Tx waits for a signal from the model before binding
2) The datapackets are 16 bytes
3) data appears to be 8-bit, unencrypted
4) the last byte is a checksum of the packet
5) the tx transmits 4 packets on the 1st channel, then 1 packet on the 2nd, the repeats
6) packets are sent every 10msec
7) data is only transferred from the Rx to the Tx during binding (handshake)

I'll start a new thread with more details as I spend some time actually analyzing the protocol.
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Old Nov 20, 2012, 02:19 AM
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Originally Posted by j35u5fr34k View Post
Instructions are listed here:

http://deviationtx.com/release-notes/12-version-1-1-2

You won't brick it.
what do you need to connect the devo 6 tx to the computer to update the firmware?
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Old Nov 20, 2012, 02:53 AM
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Originally Posted by achogg33 View Post
what do you need to connect the devo 6 tx to the computer to update the firmware?
A simple standard USB cable, you've got with the tx.
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Old Nov 20, 2012, 10:14 AM
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Quote:
Originally Posted by PhracturedBlue View Post
I got my Hubsan x4 today. I immediately opened up the Tx, and grabbed some captures.
The protocol looks pretty straight-forward:
1) The Tx waits for a signal from the model before binding
2) The datapackets are 16 bytes
3) data appears to be 8-bit, unencrypted
4) the last byte is a checksum of the packet
5) the tx transmits 4 packets on the 1st channel, then 1 packet on the 2nd, the repeats
6) packets are sent every 10msec
7) data is only transferred from the Rx to the Tx during binding (handshake)

I'll start a new thread with more details as I spend some time actually analyzing the protocol.
That's great to hear! Hope you can get this working in deviation It's an awesome little quad!
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Old Nov 20, 2012, 04:44 PM
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Obviously all depends on what you want to do. Here you have another more items but with connectors.

2.8''. I think it doesn't fit on the hole and place of the Devo 7 transmitter. The PCB probably is too much larger and will have problem with the space for the buttons. And the height of the screen is a little bigger than the hole in the transmitter.
http://www.ebay.com/itm/2-8-inch-320...item2a24ef5472

2.4''. I think that this fits without problem. The hole is bigger than the screen.
http://www.ebay.com/itm/2-4-inch-TFT...item4608fa2f68

2.2''. It also fits.
http://www.ebay.com/itm/2-2inch-320x...item3a75199a37

I can't imagine how to change the screen without soldering. ? If you change the main board by replacing with a generic main board, you will need to connect to it the potentiometers, switches and the new screen, etc.

When I talk about the hole you need see that the transmitter has a plastic frame with five screws, that you can remove by forcing a little to extract it and you get a bigger hole than the original for the original screen, and allows you to place there a touch screen.

I hope it will be usefull for you.
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Old Nov 20, 2012, 09:34 PM
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Originally Posted by RCaDDiCT! View Post
That's great to hear! Hope you can get this working in deviation It's an awesome little quad!
Well, I'm making good progress towards supporting this model. I have enough info to write a (rough) driver, so hopefully I'll have something toreport in the next 24 hours.

One note though: It doesn't look like you'll be able to use the V911 module for this. the V911 module does not connect the LNA to the antenna, so it is likely that you cannot receive signals, and the Hubsan requires bi-directional communication for binding.

So that leaves the XL7105-SY module (~1.3mW, no PA/LNA) or the Aliexpress/ebay module (16dBm PA/LNA=???). I have all 3 modules so I'll test them all. I'm not sure how the ebay module is wired, and whether I need to configure the GPIO to control the LNA or not.

That said, it may be possible to live without the bidi communication. It doesn't appear that the Tx uses any of the info sent back by the Rx, so we may be able to get by without it, though it would likely mean that binding won't be as reliable.
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