SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Aug 11, 2009, 02:18 AM
Registered User
Joined Nov 2006
39 Posts
Hi, I have heard, that there is alternative software and software for Pocket PC for this radio. I tried to find it, but in this very long thread it is almost impossible.
Please can you give me some link? Thanks a lot.
holda29 is offline Find More Posts by holda29
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 11, 2009, 02:27 AM
Heli Humbled Daily
Riverside, CA
Joined Jul 2006
2,973 Posts
Holda, just up on the right side of your post is a button that says "Search this Thread."

Type in "PPC" and one of the first links you will see is to this:

http://www.rcgroups.com/forums/showthread.php?t=1013232

and also this:

http://www.rcgroups.com/forums/showthread.php?t=999541
Telemachus is offline Find More Posts by Telemachus
Reply With Quote
Old Aug 11, 2009, 12:59 PM
R.I.P, Aardvark.
F-111 John's Avatar
Holt, MI
Joined Jan 2009
1,554 Posts
...
F-111 John is offline Find More Posts by F-111 John
Last edited by F-111 John; Aug 11, 2009 at 01:00 PM. Reason: Wrong Thread
Reply With Quote
Old Aug 12, 2009, 05:34 PM
Registered User
Joined Jul 2009
648 Posts
I took again a look on the datastream going from the receiver board to the main board of the receiver using the data from that old post http://www.rcgroups.com/forums/showp...postcount=1413

Thanks to the ideas of vince29 i was able to decode those at that time posted data stream. I could read the length of the channel pulses for channel 1 to 5 (that is how far I had counted the bits at that time)

It showed up, that there was 1 startbit, 16 databits and 5 stopbits per channel, as far as I had bits for the stream.

Stick left, middle, right decoded to pulse length of 1.231msec, 1.548msec and 1.874msec. Channel 5 (VarA at minimum) was 1.020msec.

These values look realistic to me.

I dont know what's going on further in the datastream, but, maybe vince29 comes up some time with more knowledge.

Reinhard
ReSt is offline Find More Posts by ReSt
Reply With Quote
Old Aug 12, 2009, 11:01 PM
master of the universe
captaingeek's Avatar
USA, CA, Novato
Joined Jul 2008
3,077 Posts
anyone have the 8 or 10 ch ver they want to sell or know of any deals on the 8ch combo? last i checked it was $90
captaingeek is offline Find More Posts by captaingeek
Reply With Quote
Old Aug 13, 2009, 02:05 AM
PJG
Ad astra per alia porci
PJG's Avatar
Joined Jul 2009
57 Posts
Fine tuning after 4 cell mod.

Referring to Mis_b's post No. 989, concerning the re-calibration of the battery state LED and warning buzzer; I found that a couple of adjustments were required on my particular CT6A Tx. Other transmitters may not need these.

1. Adjustable battery monitoring circuit: The 10k resistor between the zener and the 10k pot needed increasing to 15k, to allow sufficient adjustment from the 10k pot.

2. Warning buzzer circuit: The difference in voltage between Vcc and that on Pin 11 was sufficient to turn on the transistor (and buzzer) at full battery voltage. Inserting a small 1N4148 diode between Vcc and the transistor emitter resolved this. I now just get a brief chirp from the buzzer at switch-on, as the Tx PCB voltage ramps up and then silence, until the LED turns to red and the transistor turns on.
PJG is offline Find More Posts by PJG
Last edited by PJG; Sep 21, 2010 at 01:04 PM.
Reply With Quote
Old Aug 13, 2009, 05:06 AM
Time for another motto!
Utrecht, The Netherlands
Joined Jul 2006
1,413 Posts
Quote:
Originally Posted by vinc29
Quote:
Originally Posted by reSpawn
Hello,
since this topic is way too big, I tried reading it but I failed.
I'm interested to use this pair of Tx/Rx to transmit digital data using an mcu connected at each end. Is it possible?
It can be achieved but not as easy as uart...
The transmitter only accept ppm input and it encode the time between pulse at the S. There are 8 or 9 channel. the data are received in digital value with a 16 bits uart and transform into separate pwm channel. This is a one way transmission with no verification that the receiver is connected...

I think it will be cheaper and easier to use Xbee/Microchip or even TI modules. they all have librairies to develop small networks with two way transmit.
Besides, biderectional data will be impossible with these receivers. The tranceiver chip has the capability, but the extra hardware is not there. Things are different for the transmitter module: it has both a transmitting LNA and an on-board receiving antenna. If you bypass or remove the MCU that sits before the tranceiver chip (a7122), you are back at the original simple radio modem with GFSK encoding and simple frequency hopping capabilities. You could also use the a7122 chip and build from there, but then you would need to design and add the HF/LNA part yourself. I have read somewhere in this thread that the used chip can be replace with a AVR chip with the same footprint, it could even be a re-badged avr.
HTH
JelleB is offline Find More Posts by JelleB
Reply With Quote
Old Aug 13, 2009, 06:09 AM
Registered User
Joined Sep 2004
206 Posts
Quote:
Originally Posted by ReSt
I took again a look on the datastream going from the receiver board to the main board of the receiver using the data from that old post http://www.rcgroups.com/forums/showp...postcount=1413

Thanks to the ideas of vince29 i was able to decode those at that time posted data stream. I could read the length of the channel pulses for channel 1 to 5 (that is how far I had counted the bits at that time)

It showed up, that there was 1 startbit, 16 databits and 5 stopbits per channel, as far as I had bits for the stream.

Stick left, middle, right decoded to pulse length of 1.231msec, 1.548msec and 1.874msec. Channel 5 (VarA at minimum) was 1.020msec.

These values look realistic to me.

I dont know what's going on further in the datastream, but, maybe vince29 comes up some time with more knowledge.

Reinhard
Very interesting. What is the polarity of the startbit (i.e. does it begin Positive-to-Negative or Negative-to-Positive) and how long is it (i.e. how many micro-seconds)? What is the duration between bits? Are the bits 0 to 3volt or 0-5volt? Are the bits symmetrical (i.e. same off-time as on-time)?

Do you know what bits are sent from the Main Rx to the Satellite Rx to get the Satellite Rx to begin receiving the transmitted signal and sending data? I have tried sending several combinations from a PIC Micro but cannot get the satellite Rx to begin receiving (i.e. cannot get the Red LED to come one I dont have an oscilloscope). It operates perfectly when connected to the Main Rx.
CitizenKane is offline Find More Posts by CitizenKane
Reply With Quote
Old Aug 13, 2009, 11:19 AM
Registered User
Joined Jul 2009
648 Posts
Quote:
Originally Posted by CitizenKane
Very interesting. What is the polarity of the startbit (i.e. does it begin Positive-to-Negative or Negative-to-Positive) and how long is it (i.e. how many micro-seconds)? What is the duration between bits? Are the bits 0 to 3volt or 0-5volt? Are the bits symmetrical (i.e. same off-time as on-time)?
For some pictures please have a look here http://www.rcgroups.com/forums/showp...postcount=1388

A bit is about 24usec long resulting in a datarate of about 41.66 kBd.
One-bits are negative, zero-bits positive level. There is no duration between bits.
As long as the level is negative, there are one-bits (no return to zero).

I have counted one measured bitstream up to and including channel 5.
(It looked like there were 9 blocks, the first 6 blocks having data for 6 channels, the last block maybe a checksum. But I don't know what is in between.)

There (thanks vince29) I could see:

Single Channel data start with one startbit (-) followed by 16 databits followed by 5 stopbits (+) followed by the next single channel data according to this scheme.
The 16 databits come with least significant bit (LSB) first. Reverse the bit sequence. Subtract this value from 65536. That is the timing value of one channel in usec.

Example stream:
10111010100011111000001011111111001111100000101101 0101101111100000.......

.1011101010001111100000 first 22 bits (1S,16D,5Stp)
. 0111010100011111 16 databits LSB first
. 1111100010101110 bitsequence reversed (MSB first)
. 1111 1000 1010 1110 Hex F8AE -> dec 63662
65536 - 63662 = 1874 length of channel pulse = 1874usec =1.874msec

As the receiver is stabilized to 3.3V supply voltage the signal level is in the range of 0 to +3 volt.

Quote:
Do you know what bits are sent from the Main Rx to the Satellite Rx to get the Satellite Rx to begin receiving the transmitted signal and sending data?
No, I have no idea. I hope, vince29 may come up with some more information about that.

Reinhard
ReSt is offline Find More Posts by ReSt
Reply With Quote
Old Aug 13, 2009, 07:03 PM
Registered User
Cornwall, UK
Joined Dec 2007
110 Posts
Quote:
Originally Posted by PJG
Referring to Mis_b's post No. 989, concerning the re-calibration of the battery state LED and warning buzzer; I found that a couple of adjustments were required on my particular CT6A Tx. Other transmitters may not need these.

1. Adjustable battery monitoring circuit: The 10k resistor between the zener and the 10k pot needed increasing to 15k, to allow sufficient adjustment from the 10k pot.
I almost had the same problem with my Turborix 6ch. I was right at the limit of the 10k pot.


After doing the 4-cell mod, is it safe to run the Tx using alkaline batteries? I'll normally be using NiMH, but I'm wondering if alkaline could be used in an emergency. The higher voltage makes me wary of trying it.
clockworks is offline Find More Posts by clockworks
Reply With Quote
Old Aug 14, 2009, 06:51 AM
Registered User
Joined Sep 2004
206 Posts
ReSt thanks very much for sharing your findings, they are very helpful. One question - the post you reference with the scope pictures state: "The following pictures show the data going from the main receiver to the main board of the receiver.", not sure what this means? Are they taken internal to the Main Rx or on the data line between the Main Rx and the Satellite Rx?
CitizenKane is offline Find More Posts by CitizenKane
Reply With Quote
Old Aug 14, 2009, 07:07 AM
Registered User
Joined Jul 2009
648 Posts
Quote:
Originally Posted by CitizenKane
ReSt
... Are they taken internal to the Main Rx or on the data line between the Main Rx and the Satellite Rx?
Satellite receiver disconnected.
Pictures taken on one of the solder pins, where the rf board of the main receiver is wired to the mainboard of the main receiver.

(Datastream at the external plug of the satellite to the main receiver visually looked the same).

Reinhard
ReSt is offline Find More Posts by ReSt
Reply With Quote
Old Aug 14, 2009, 07:18 AM
Registered User
(Jo)Hannes's Avatar
Trier, Germany
Joined Aug 2007
513 Posts
We have the Problem that the receivers are not working correct or jittering as hell, depending from which BEC(ESC) they are driven. The problems never occour if we use a normal receiver battery instead of the BEC. The same BEC(ESC) works without problems with my other 35MHz, 27MHz and Assan receivers. Allthough on other BECs the same receiver works flawlessly...

Anyone experienced the same problems?
(Jo)Hannes is online now Find More Posts by (Jo)Hannes
Reply With Quote
Old Aug 14, 2009, 10:40 AM
Time for another motto!
Utrecht, The Netherlands
Joined Jul 2006
1,413 Posts
Quote:
Originally Posted by ReSt
For some pictures please have a look here http://www.rcgroups.com/forums/showp...postcount=1388

[...]
Subtract this value from 65536.
ehmm, are you sure you have the right polarity? If you subtract 16 bits from 1111 1111 1111 1111, aren't you essentially flipping each bit in your number? Better start then with the correct bit-value for a low voltage = 0, high voltage = 1.

But apart from that, I really appreciate the effort.
JelleB is offline Find More Posts by JelleB
Last edited by JelleB; Aug 14, 2009 at 11:08 AM.
Reply With Quote
Old Aug 14, 2009, 11:35 AM
Registered User
Joined Jul 2009
648 Posts
Quote:
Originally Posted by JelleB
ehmm, are you sure you have the right polarity? If you subtract 16 bits from 1111 1111 1111 1111, aren't you essentially flipping each bit in your number? Better start then with the correct bit-value for a low voltage = 0, high voltage = 1.

But apart from that, I really appreciate the effort.

Here in my post (long ago and hidden in the file)
http://www.rcgroups.com/forums/showa...mentid=2656466

I mentioned
Quote:
Data that the receiverboard sends to the main board
supposed, that the level without signal represents the logical 0
So take it this way or that way, the result is nearly the same.

I simply supposed, that a startbit is a 1 bit and the stopbit is a 0.
If it's vice versa, then let's take it the other way.

Today I measured the datastream that the main receiver sends to the satellite receiver after power on. I will post it next time.

We should clarify what we want to be a One-bit before.

Reinhard
ReSt is offline Find More Posts by ReSt
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New Product X8---new 2.4GHz Radio System ASSAN Radios 5708 Jun 25, 2014 01:20 PM
Yippee! New 2.4GHz DSM radio - New standard? PrasadL Scratchbuilt Indoor and Micro Models 12 Jun 03, 2013 07:03 AM
For Sale NEW - 2.4GHZ 2 channel Pistol R/C system SRM Cars - Cars and Parts (FS/W) 0 Oct 22, 2008 09:39 AM
FS: 1x Used 1x New 2.4ghz Wireless video cameras with receiver Nik-rc Aircraft - Electric - Airplanes (FS/W) 4 Nov 30, 2004 06:21 PM