HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Nov 12, 2012, 10:40 PM
yud
Registered User
Australia, NSW, Sydney
Joined Nov 2012
57 Posts
Quote:
Originally Posted by SadSack View Post
Yes
Thanks!

EDIT:
But I see that it also involves soldering a transceiver into the Devo Tx if I want to fly other vendors helis.
Correct?
yud is online now Find More Posts by yud
Last edited by yud; Nov 12, 2012 at 11:22 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 12, 2012, 11:48 PM
Registered User
j35u5fr34k's Avatar
United States, MI, East Tawas
Joined Aug 2011
120 Posts
Go to deviationtx.com and see what is supported and what is not with or without soldering.
j35u5fr34k is offline Find More Posts by j35u5fr34k
Reply With Quote
Old Nov 13, 2012, 06:49 AM
Registered User
Tromsų / Norway
Joined Nov 2009
85 Posts
I`m a new owner of a Devon-12S and I fly FPV most of the time :-)
To get long range with my radio (Futaba 9C) I`m using Dragon Link
Where can I find the PPM-stream from inside the radio?
Kaspers1 is offline Find More Posts by Kaspers1
Reply With Quote
Old Nov 13, 2012, 07:25 AM
Registered User
Joined Jan 2012
682 Posts
Quote:
Originally Posted by Kaspers1 View Post
I`m a new owner of a Devon-12S and I fly FPV most of the time :-)
To get long range with my radio (Futaba 9C) I`m using Dragon Link
Where can I find the PPM-stream from inside the radio?
I'm not familiar with the Devo12, but on the other models, if you plug into the phono jack and ensure the Tx pin is driven (high I think), the Tx will shut off the regular radio, and will transmit over PPM in trainer mode.

There is no PPM available when the Tx is transmitting over its radio.
PhracturedBlue is offline Find More Posts by PhracturedBlue
Reply With Quote
Old Nov 13, 2012, 07:08 PM
Registered User
Joined Jul 2009
63 Posts
I can build the firmware fine now once I switch to the libopencm3 in the
git version specify in README.

Does any one know if I can use dfu util in linux to flash the firmware.
I saw a while back there is some discussion about that and seems
some change to the CRC is required. Just wondering if I can avoid
using the windows machine for development.

I also notice the SPI transfer does not use interrupt at all. It loop until
the transfer is done for a byte. The libopencm3 looks provide API
to use interrupt. But I haven't found an example how to do that yet.
printk is offline Find More Posts by printk
Reply With Quote
Old Nov 13, 2012, 08:53 PM
Registered User
Joined Jan 2012
682 Posts
Quote:
Originally Posted by printk View Post
Does any one know if I can use dfu util in linux to flash the firmware.
I saw a while back there is some discussion about that and seems
some change to the CRC is required. Just wondering if I can avoid
using the windows machine for development.
well...it can be done depending on your tolerance for risk. At least one user corrupted his bootloader using it though (I have no idea how, that shouldn't be possible). In that case, you need to use a SWD to flash the MCU and reload the bootloader (there should be a link to it early in this thread). Additionally, as you mentioned, the Windows version of the dfuse tool modifies the CRC when it writes the dfu. The CRC we currently have worked for one user with dfu-utils but not another (this may be a Devo8 vs Devo8s thing). Personally, i just use a Windows computer to flash the dfu despite doing all development on Linux.

Quote:
I also notice the SPI transfer does not use interrupt at all. It loop until
the transfer is done for a byte. The libopencm3 looks provide API
to use interrupt. But I haven't found an example how to do that yet.
Well, we're already in an interrupt handler when writing to the SPI, so I don't think it would help to use an interrupt to wait for completion.
PhracturedBlue is offline Find More Posts by PhracturedBlue
Reply With Quote
Old Nov 13, 2012, 09:13 PM
Better then Sliced Bread!
NorCalMatCat's Avatar
United States, CA, Arcata
Joined Oct 2011
2,650 Posts
I have a question, I am considering putting together a virtual control interface for my FPV plane, something that will give me things like light control, cargo bay door control, flaps, and other things, now my approach to this is to pretty much get way more channels then what is possible standard. I.E. Use 3 channels to transmit data to an arduino onboard which will decode the protocol I make up out of the PWM signals, but what my question is is is the data going over the airwaves completely accurate? I.E. if the radio transmits 8 channels, does the RX (assuming the packet isn't lost) get all 8 channels in digital identical to how it was TX, I.E. Basically assuring I can get a full byte per channel pretty much and know that what was TX'd was RX'd.
NorCalMatCat is offline Find More Posts by NorCalMatCat
Reply With Quote
Old Nov 13, 2012, 09:26 PM
Registered User
Joined Jan 2012
682 Posts
Quote:
Originally Posted by NorCalMatCat View Post
I have a question, I am considering putting together a virtual control interface for my FPV plane, something that will give me things like light control, cargo bay door control, flaps, and other things, now my approach to this is to pretty much get way more channels then what is possible standard. I.E. Use 3 channels to transmit data to an arduino onboard which will decode the protocol I make up out of the PWM signals, but what my question is is is the data going over the airwaves completely accurate? I.E. if the radio transmits 8 channels, does the RX (assuming the packet isn't lost) get all 8 channels in digital identical to how it was TX, I.E. Basically assuring I can get a full byte per channel pretty much and know that what was TX'd was RX'd.
The cyrf6936 can be configured for different packet sizes. but yes, there is a builtin CRC that gaurantees all or nothing reception (if you get a packet, it is what was sent by the Tx)
PhracturedBlue is offline Find More Posts by PhracturedBlue
Reply With Quote
Old Nov 13, 2012, 09:29 PM
Registered User
Joined Jul 2009
63 Posts
Thanks. it looks like I have to use windows then. That sucks.

I see. So your all the DSM2 processing was in the timer context.
Do you have other task need to run at the same time like other
interrupt source or the main loop etc? If CPU has nothing else
better to run, blocking on he timer interrupt is fine.

Quote:
Originally Posted by PhracturedBlue View Post
well...it can be done depending on your tolerance for risk. At least one user corrupted his bootloader using it though (I have no idea how, that shouldn't be possible). In that case, you need to use a SWD to flash the MCU and reload the bootloader (there should be a link to it early in this thread). Additionally, as you mentioned, the Windows version of the dfuse tool modifies the CRC when it writes the dfu. The CRC we currently have worked for one user with dfu-utils but not another (this may be a Devo8 vs Devo8s thing). Personally, i just use a Windows computer to flash the dfu despite doing all development on Linux.


Well, we're already in an interrupt handler when writing to the SPI, so I don't think it would help to use an interrupt to wait for completion.
printk is offline Find More Posts by printk
Reply With Quote
Old Nov 13, 2012, 09:32 PM
Better then Sliced Bread!
NorCalMatCat's Avatar
United States, CA, Arcata
Joined Oct 2011
2,650 Posts
Awesome, then I will have no probs transmitting a full byte per channel! I think I could actually fit my entire protocol need (8 total channels), down to a single channel! Which is quite awesome. Basically Channel 1 to 4 will be the basic flight controls, and ALL other needs will be handled via an arduino on the plane and using channel 5 as a single byte data RX to control all other 8 needed channels hehe.
NorCalMatCat is offline Find More Posts by NorCalMatCat
Reply With Quote
Old Nov 13, 2012, 09:36 PM
Registered User
Joined Jul 2009
63 Posts
I think may be Cat was worry about convert to PPM in some of the
middle stage will change the bit some how. If you are using satellite receiver,
which has access to the receiver digital line. The channel data is not changed
from TX to RX. However, if receiver already convert the channel data
to PPM, then there is no guarantee measuring the PPM will resulting the
same digits you send from TX.

There is also other things you need to consider, e.g. 100% in TX is not
really 100% at the channel data. Some TX use 150% as the upper limited
etc.

Quote:
Originally Posted by PhracturedBlue View Post
The cyrf6936 can be configured for different packet sizes. but yes, there is a builtin CRC that gaurantees all or nothing reception (if you get a packet, it is what was sent by the Tx)
printk is offline Find More Posts by printk
Reply With Quote
Old Nov 13, 2012, 09:39 PM
Better then Sliced Bread!
NorCalMatCat's Avatar
United States, CA, Arcata
Joined Oct 2011
2,650 Posts
Not PPM, I didn't even think you could get PPM from the Devo RX's? The idea is to have an arduino connected to the PWM output of that specific channel and read the byte on it and do what it should do accordingly, assuming I cat an accurate byte from the PWM signal being generated by the RX, the actual % of the PWM generated at radio doesn't matter because I would set the channel output direct and precicely in software, not via stick/pot/trim/switch.
NorCalMatCat is offline Find More Posts by NorCalMatCat
Reply With Quote
Old Nov 13, 2012, 09:47 PM
Registered User
Joined Jan 2012
682 Posts
Quote:
Originally Posted by NorCalMatCat View Post
Not PPM, I didn't even think you could get PPM from the Devo RX's? The idea is to have an arduino connected to the PWM output of that specific channel and read the byte on it and do what it should do accordingly, assuming I cat an accurate byte from the PWM signal being generated by the RX, the actual % of the PWM generated at radio doesn't matter because I would set the channel output direct and precicely in software, not via stick/pot/trim/switch.
having the rx output PWM, and then converting that back to binary data will likely introduce inaccuracy. If you try to mix several channels and retreive the binary data, you end up with the LSB not aligning, and so an off-by-one will give you a corrupt result.
PhracturedBlue is offline Find More Posts by PhracturedBlue
Reply With Quote
Old Nov 13, 2012, 10:00 PM
Better then Sliced Bread!
NorCalMatCat's Avatar
United States, CA, Arcata
Joined Oct 2011
2,650 Posts
If you do not believe the PWM is accurate enough to recreate the full byte, what about say 64 steps, I could re-create the entire byte across 4 channels that way if I wanted too, though even at 64 steps I could get away with using 2 channels for my needs.
NorCalMatCat is offline Find More Posts by NorCalMatCat
Reply With Quote
Old Nov 13, 2012, 10:01 PM
Better then Sliced Bread!
NorCalMatCat's Avatar
United States, CA, Arcata
Joined Oct 2011
2,650 Posts
Actually even better then all this guessing, I will just experiment and report back.

And a side note, is there any easily accessable IO method on the Devo 8 hardware? An unused UART, or SPI or I2C bus? Anything I could connect an external arduino to and have 2 way communication to the radio?
NorCalMatCat is offline Find More Posts by NorCalMatCat
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Wanted Broken Walkera Devo and Spektrum tx itsmillertime Aircraft - General - Radio Equipment (FS/W) 1 Mar 20, 2012 04:37 AM
For Sale Walkera Devo 7 TX/Devo RX2625H Combo for sale Tom Z Aircraft - General - Radio Equipment (FS/W) 0 Oct 06, 2011 12:33 PM
For Sale Walkera Devo 7 TX/Devo RX2625H Combo for sale Tom Z Aircraft - Electric - Helis (FS/W) 0 Oct 05, 2011 11:38 AM
Discussion New Walkera Devention Devo 12 TX w/ Touch-Screen hobbypartz Radios 2 May 08, 2011 11:38 PM
Discussion New Walkera Devention Devo 12 TX w/ Touch-Screen hobbypartz XHeli 0 May 05, 2011 11:19 PM