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Old Jan 24, 2012, 06:16 PM
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Quote:
Originally Posted by GolfFear View Post
no PPM signal ?
ah okay, i remember @ the german forum where they mod the eurgle module, that there must be a 12K resitsot between PPM and V+ because the PPM "area" in the kopropo don't ant to enable.

so, i will install it now by writing this post but the red led still light continous....



thanks
I put the oscilloscope on the PPM pin, and I confirm:
1. PPM Signal is inverted
So, use this code
Quote:
TCCR1B = (1<<ICES1) | (1<<CS11); // capture using rising edge, prescaler = 8
// TCCR1B = (1<<CS11); // capture using falling edge, prescaler = 8
2. PPM Signal is 6volt, so you should better put a divider to step down the voltage to 3.3 (or less)
Use this schema

3. Channel order is : steering, throttle, channel 3
So, use this code
Quote:
static byte ChanIndex[] = {1,3,2,4,5,6}; //PPM to DSM2 Channel Mapping Table
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Old Jan 25, 2012, 06:48 PM
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great ! thank you very much

absolutley great, today i will solder it and tell what it work
4k7 = 4,7k ohm or 4700 ohms right ?
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Old Jan 27, 2012, 08:54 PM
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Quote:
1. PPM Signal is inverted
So, use this code
check

Quote:
2. PPM Signal is 6volt, so you should better put a divider to step down the voltage to 3.3 (or less)
check

Quote:
3. Channel order is : steering, throttle, channel 3
check

but the same procedure

steering and trottle servo turn voll left and the other full right - no reaction.
testet on Kopropo ex1 mars
kopropo ex1
and 3 other noname PPM transmitter (on oll transmitter my old DX2.0 module does work)

i've checkt every wire, mesaured any resistor, the lm317 ....
i've checkt all 9 versions of the code (static byte channel original, mod, TCCR1B normal, reverse...)

on power on the same procedure:
turning on transmitter - gren led short blinks up, the red led of the audrino lights continous.
the TX module blinks for 4 seconds and then go into normal mode - servos comes from failsafe position in the full left and full right position and gives no reaction whatever i did on the transmitter.

someone here says when the red led light continous, there are no PPM signal from transmitter to audrino ?

hmmm, where is the problem (ok, i'm a small problem because no idea about cc programming ) ?
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Old Jan 29, 2012, 08:50 PM
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Ok, doing some research for a different application.... Could someone catch me up on what has improved in this thread?

I have both LP5DSM and soon a dx4e to use for testing.

Has the 6 channel "limit" been fixed?

Has anyone really cracked DSMx binding and operation or is it still a work in progress?

Are there sources for raw AVR or PIC or has most of the recent work all been on Arduino? I'm most interested in the work done on the 9x to natively support the RF module instead of the PPM conversion, but I'll take what I can get.
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Old Jan 29, 2012, 09:31 PM
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- There is a 6 channel limit. I don't think the module sends more than that(LP4/LP5 and DX4e). For sure nothing shows up at the receiver.

- DSMx works with the DX4e module, as does range check. Codes were posted earlier in the thread for this.

- You can send the DSMx codes to the LPx modules. They seem to ignore the first byte of the header altogether.

- Model match works with the DX4e module. Second byte in the header sent at binding locks the receiver to that number.
LPx modules ignore this byte.

- If the receiver supports it then you can send the data every 11 msec. AR8000 and the MCPx both support this mode. Tested with the LP4 module and the DX4e one.

All of this is implemented in the ER9X firmware. (Except the 11msec part, but I have been using that mode with my MCPx for a couple of weeks now. Just want to do a bit more testing before I suggest adding it to the release code)

Pat MacKenzie
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Old Jan 29, 2012, 11:05 PM
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I wonder why there is a 6 channel limit. Maybe someone with a higher level TX can shed some light on this for us.

But at least there is still a way to get a 6 channel module since it doesn't look good for being able to buy the 8 channel modules. I'll have to round up my empty XPS module case and start on a circuit board for TheSteve's original design.
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Old Jan 29, 2012, 11:31 PM
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My guess is that they simply wrote the code that way. No reason for a low end module to ever go over 6 channels, so why bother with more.

I do have an X9303. They have a processor between the encoder board and the "module". Lots of lines used between the two. Not sure I want to take the risk of damaging a $500 transmitter to decode what is going on.

6 will do almost all models anyway. The only things I have that go to 7 are full house electric sailplanes.

Pat MacKenzie
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Old Jan 29, 2012, 11:43 PM
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Looking at the ID on the board it seems to be the same as used in the 8 channel PPM modules so I wonder if one of those might provide the key. I'll have to review the notes in the beginning to see if I can sniff something from one of my purchased modules, maybe we simply have the data wrong on 7 to 12+

Any software recommendations to use for logging this data?
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Old Jan 29, 2012, 11:54 PM
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AFAIK, the standard PC hardware can't do 125K baud rates. Has to do with the crystal based oscillators they use not being the correct frequency.

I used a parallel port logic analyzer. Worked very well. You get some glitches in the data, but it is easy to see what is going on. You can set it up to decode the data directly into hex.
Best thing- it is free

http://www.codeproject.com/Articles/...Logic-Analyzer

If you decide to use it I can help you with the settings that seem to work the best.

As far as the data being wrong - the modules seem to just take the 10 bit channel data and ignore the 4 byte channel number field completely.
So for the LPx module all you need to do is send two random bytes as a header and then 6 pairs of bytes that have the pulse widths and the correct data will be sent to the receiver.
The long space between packets is what actually is important.

Pat MacKenzie
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Last edited by pmackenzie; Jan 29, 2012 at 11:59 PM.
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Old Jan 30, 2012, 12:25 AM
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I don't think I have anything left that has a par. port. I seem to recall that we could use a decent USB-rs232 adapter set to the correct bit rate. I'll look around and see if I have something that might have a par. port, but it is going to be a very slow machine if I have one.

That's interesting to know that they aren't even looking at the channel order byte.
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Old Jan 30, 2012, 02:45 AM
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FTDI sells USB-to-TTL-serial cables that can do just about any baud you ask for.

Ari.
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Old Jan 30, 2012, 06:08 AM
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When I looked into it most said that they would accept different rates, but just round to the nearest value, so 125K turns into 115200

http://forums.ni.com/t5/Instrument-C...ud/td-p/110129

The other nice thing about the logic analyzer method was that it showed not just the decoded data but the time between packets. And you can use it to debug your code

Pat MacKenzie
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Old Jan 30, 2012, 09:27 AM
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Quote:
- DSMx works with the DX4e module, as does range check. Codes were posted earlier in the thread for this.

- You can send the DSMx codes to the LPx modules. They seem to ignore the first byte of the header altogether.
Has anyone worked on the telemetry protocol yet?

As Spek***m does not offer any logging device yet (except the iPhone module), that could be a nice project.
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Old Jan 30, 2012, 10:37 AM
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I have a couple ftdi based devices I can try, just need to make some clip leads for them.

One of these days I need to get a decent logic analyzer for stuff like this.
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Old Jan 30, 2012, 01:14 PM
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i need help for my tx.....
why it dosn't work? hmpf

any idea ?
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