Espritmodel.com Telemetry Radio
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Old Jun 09, 2009, 11:05 AM
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earlwb's Avatar
USA, TX, Grapevine
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wjbite, I would not plug a 7.2c Lipo pack directly into the receiver. The specs state 5.5v max, then don't exceed that. use a 4.8v pack or a ESC with a BEC in between. The ESC does not have to be plugged into the throttle channel. A decent ESC will refuse to run the motor if it isn't at the zero throttle setting. Now one can use 4 AA battery cells in series. Even though 4 AA batteries put out 6 volts, this does not cause a problem with most all of the radio systems. The 4 AA's usually cannot provide high amps like nicads can.

I have seen quite a few people try plugging in the 7.2v 2s1p Lipo packs into a reciever with obvious bad results. yeah that balance plug is dangerous in that respect, people are able to plug them in amazingly enough. I guess the manufacturers should put in more caveats. But does anyone actually read the instructions first?

Humm, but since a reciever only costs like $13.00 dollars, what the heck, try plugging in a 7.2v Lipo and see what happens. You definitely have my curiosity piqued. I would not try servos though, unless you have some servos rated for 7.2v.
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Old Jun 09, 2009, 11:21 AM
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Espaņa, AL, Sevilla
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There is a problem to make this experiment: There are input capacitors connected in parallel with the input, before the voltage regulators, and these are rated 6 V (at least in my RX).

Somebody posted having blown these caps, even feeding it with 6 V (with an ESC, maybe it give sligtly above 6 V and/or the caps were not very good). The good news is the RX still worked, once he removed the blown capacitors.

I'll try to find this post.

Another problem if you feed it with higher voltages is that power dissipated in the regs increases, and may exceed ratings. And, finally, you could also have problems with the servos.
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Last edited by MoFl; Jun 09, 2009 at 11:37 AM.
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Old Jun 09, 2009, 11:24 AM
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Joined May 2009
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Stick problem

Hi!

I've recently get a Hobby City 6ch transmitter, and i have a problem.
It worked for a week, i used it with a simulator.

This morning, when i turned on the tx, two of the directions failed to work, they are stucked to the lowest left position (the ppm signal, the physical stick is working)
The mid point of the another directions are moved away. The throttle directions (mode 2) low point is in the 512 position, the right stick's horizontal directions mid point is somewere in the right section.

It looks like the reference points of the potentiometers are moved.

What can i do with it?

Thank you for the response,
Scytale
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Old Jun 09, 2009, 11:30 AM
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Espaņa, AL, Sevilla
Joined Apr 2007
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Check the mechanic part of the joysticks. Several problems have been reported (for example, loose nuts).

Also, others have reported cold/bad solders.

Have a look here and here
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Last edited by MoFl; Jun 09, 2009 at 11:39 AM.
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Old Jun 09, 2009, 11:37 AM
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signguy's Avatar
Swansea, Massachusetts
Joined Dec 2004
2,088 Posts
Quote:
Originally Posted by keepitsimple

hello,
here is some more interesting stuff for programmer and hobbyist.

Description of interface pinning and signals
/************************************************** *******
Chassis connector pinning as seen at the back of the transmitter
----------------------------------------------------------------


Pin 1 : PMM signal
Pin 2 : +5 Volt
Pin 3 : RX RS232 Serial data input ( TTL levels(0..5Volt) , ATTENTION !!! NOT RS232 levels(+15,-15 .. +3,-3 Volt)
Pin 4 : TX RS232 Serial data output ( TTL levels(0..5Volt) , ATTENTION !!! NOT RS232 levels(+15,-15 .. +3,-3 Volt)
Shield : Ground


RS232 Serial Data specification
------------------------------

115kilobaud , 8 bit , 1 stopbit , noparity , nohandshake

A string of 18 bytes is send every 20mSec by transmitter.
Data burst duration (86.4uSec * 18 Bytes) is approx 1.5552mSec
So we have 18.4mSec to do some great stuff with a microcontroller.

PMM signal specifations
-----------------------

A burst of 7 falling (H->L) edges is send every 20mSec.
Pulse time is time between 2 falling edges
Low part of pulse time is always 0.4mSec.



I inserted this picture because my 'beautiful' ascii pulses are mutilated by probably every available font.

sorry for the bad quality of the picture, i need a better picture server.


/************************************************** *******
is it possible to connect a usb cable directly to the radio, using the four points shown in the picture. I just bought a radio used on rc groups, but no cable came with it. Have lots of old usb cables ready to be cut up. Are there any electronics in the cable? just need it to program, maybe flight sim on clearview.
Thanks in advance, looked through the tread, but just getting more confused.

Thanks
Signguy
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Old Jun 09, 2009, 11:49 AM
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MoFl's Avatar
Espaņa, AL, Sevilla
Joined Apr 2007
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The cable has a serial to USB converter inside, and uses pins 4 and 3.

You could also use these pins 4 and 3 and connect them to the PC serial port, but in this case you need a level shifter, as the radio serial port is TTL (5V) level and the PC is RS232. Lot of info about this option has been posted some posts after the one you quotes (search RS232 in this thread), to connect the radio to PDAs-PPCs

On the other hand, to use with flight sims, pin 1 (PPM) is the one that's needed. Just 14 posts ago (907) LeadWings remembered the options with PPM to USB cables.

I've read that there's also the possibility to route PPM signal to the soundcard using PPjoy, or to theserial port with a simple interface, using also PPJoy, but I haven't tried them.
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Old Jun 09, 2009, 11:52 AM
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Kokopeli's Avatar
Rochester, NY, USA
Joined Oct 2005
2,061 Posts
Thanks, it didn't occur to me to consider the Max. voltage of the caps.
Let alone, connecting a balance plug in the the RX.
Even though I have four Rxs, I am too cheap to do a smoke test on one of my $13 receivers. I will be satisfied with the ho hum conclusion of 4.8 to 6.0 v Max.
All useful info.
What would I do without these forums?

Walt Bankes
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Old Jun 09, 2009, 12:23 PM
Up in smoke!
BlueFFF's Avatar
Greenville, TX
Joined Jun 2007
627 Posts
Signguy,

You can buy the USB cable for your TX seperately from HobbyKing.com
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Old Jun 09, 2009, 12:33 PM
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Joined May 2009
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Quote:
Originally Posted by MoFl
Check the mechanic part of the joysticks. Several problems have been reported (for example, loose nuts).

Also, others have reported cold/bad solders.

Have a look here and here
Two of the nuts was loose, but the a middle potentiometer value is same for all of them (1.5KOhm).

But what could happen for the two directions (stucked to 0 ppm), they are on different stick.

Yesterday they worked fine.
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Old Jun 09, 2009, 12:33 PM
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USA, TX, Dalworthington Gardens
Joined Aug 2007
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Quote:
Originally Posted by Lead Wings
Mr Rabbit, I haven't used the HK 4 channel as a sim controller yet, but it should be as simple as:
  1. Buy a cable. People have previously recommended the following: http://www.dealextreme.com/details.dx/sku.4603~r.12268550 http://www.dealextreme.com/details.dx/sku.11996
  2. Download FMS and install http://www.flying-model-simulator.com/
  3. You may also need to download PPJoy (this is a package that takes the USB data and converts it to a stream that FMS can read. http://www.geocities.com/deonvdw/PPJoy.htm
  4. Start PP Joy first and test it is reading the Tx (details of how to on the PP Joy web site)
  5. Start FMS and tell it to look for the gamepad and you should be good to go
Good luck. Bit of web surfing should help if you have any problems.
Well I have the HK 6 but I wouldn't sneeze for the difference...I have the Winxp cable http://www.hobbycity.com/hobbycity/s...idProduct=9043 they offer... I have FMS downloaded and installed also I have PPjoy installed as well as http://sourceforge.net/projects/smartpropoplus/ and I can config the transmitter and PPjoy allows this as well as seeing the TX...BUT when I try to use FMS and the TX I am not on any option able to get FMS to see the TX as a gamepad and I cannot get it to work. I guess I will just have to keep looking as I am sure that someone who has used this configuration before and done so sucessfully will respond in due time... I do however thank you for your input and appreciate your endevors to make my situation better.
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Old Jun 09, 2009, 12:40 PM
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BTW Signguy I also in my searchings for a way to use this TX as a sim controller found that with the Cable I got from HC http://www.hobbycity.com/hobbycity/s...idProduct=9043 I also needed this driver to make it work with my computer http://www.hobbycity.com/hobbycity/f..._Installer.zip now I can config my TX and PPjoy will see it better.
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Old Jun 09, 2009, 02:54 PM
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United States, OH, Galena
Joined Jul 2003
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Quote:
Originally Posted by wjbite
I like the wording you used, blackfoot, I may steal it for my manual.

Thanks,
Walt
Be my guest, wjbite
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Old Jun 09, 2009, 03:00 PM
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JMP_blackfoot's Avatar
United States, OH, Galena
Joined Jul 2003
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Quote:
Originally Posted by Scytale
Two of the nuts was loose, but the a middle potentiometer value is same for all of them (1.5KOhm).

But what could happen for the two directions (stucked to 0 ppm), they are on different stick.

Yesterday they worked fine.
Have you by any chance tried to recalibrate the transmitter (as a joystick) in the FMS ?
It may be that it just lost calibration.
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Old Jun 09, 2009, 03:14 PM
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Joined May 2009
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Quote:
Originally Posted by JMP_blackfoot
Have you by any chance tried to recalibrate the transmitter (as a joystick) in the FMS ?
It may be that it just lost calibration.
For diagnostics, i've used the t6config over usb cable.
Also tried with a receiver, but the situation is same for that.
It's transmitting 0 signal on two of the channels. On the another two channels, false valuest. The two knob ont the top working fine.
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Old Jun 09, 2009, 03:31 PM
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Espaņa, AL, Sevilla
Joined Apr 2007
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Quote:
Originally Posted by MoFl
There is a problem to make this experiment: There are input capacitors connected in parallel with the input, before the voltage regulators, and these are rated 6 V (at least in my RX).

Somebody posted having blown these caps, even feeding it with 6 V (with an ESC, maybe it give sligtly above 6 V and/or the caps were not very good). The good news is the RX still worked, once he removed the blown capacitors.

I'll try to find this post...
Here are the posts (rcuniverse):
Initial post
post with photos
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