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Old Feb 23, 2003, 03:34 AM
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N. Staffs, UK
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Quote:
Originally posted by joe price
Several people have inquired about using Hitec
transmitters instead of Futaba with Koichi's
infrared system i've compaired the channel assignments between the two.

Futaba channel 1 thottle
channel 2 elevator
channel 3 aileron

Hitec channel 1 aileron
channel 2 elevator
channel 3 throttle

Actually Hitec and Futaba channel assignments are identical at

Aileron 1, Elevator 2, Throttle 3 and Rudder 4

JR uses different channels

Throttle 1, Aileron 2, Elevator 3 and Rudder 4

Hitec Tx should work with code designed for Futaba. JR won't, Sanwa/Airtronics is different again and Multiplex use yet another variant though most of their Txs allow channels to be assigned as you wish.

HTH - Steve
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Old Feb 23, 2003, 05:31 AM
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Italy
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steve, joe,

thanks for explanations about Hitec and Futaba's channels.
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Old Feb 23, 2003, 06:10 AM
Was that my 15 minutes?
Andy Birkett's Avatar
Leicester. UK
Joined Jan 2002
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BTW people who managed to get my rx decoder to work. It should be able do detect the transmitter type and assign the throttle channel accordingly.

Andy
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Old Feb 23, 2003, 06:41 AM
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Zama city, Kanagawa, Japan
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I am using Airtronics RD6000.
Koichi's Pic program for TX fits to this transmitter without any modifications whenever I use 3ch.
My RX layout is 1ch elevator 2ch aileron 3ch throttle while Futaba is 1ch aileron 2ch elevator 3ch throttle I think.

I did 2nd experiments yesterday in the two basketball court size gym. I could not find any problems in there. IR beam arrived all over the gym.

Attached picture shows the problem currently I have, that JST connectors are too big now......
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Old Feb 23, 2003, 08:29 AM
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MSC Rödinghausen, Germany
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Hi,

I have built another infrared receiver, this time including a DC booster that can supply a pager motor.

I have used the Panasonic IR sensors this time; they seem to be more sensitive than the Vishay Telefunken ones. At least I did not have glitches today even when standing at one end of our 45m long indoor site and flying at the other end.

See more details to the model here .

Regards, Jochen
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Old Feb 23, 2003, 08:30 AM
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Oops, forgot the picture:
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Old Feb 23, 2003, 09:10 AM
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Quote:
Originally posted by jberg
[B]I have used the Panasonic IR sensors this time; they seem to be more sensitive than the Vishay Telefunken ones.
What part number? PNA4602?
Thanks,
Pat MacKenzie
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Old Feb 23, 2003, 12:24 PM
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Pat,

nope, I use the PNA4612, which is called a "high sensitivity version". Obviously it is at least better than the Vishay Telefunken TSOP1838.

Regards, Jochen
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Old Feb 23, 2003, 12:37 PM
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Thanks Jochen,
The PNA4612 is available from Digikey here, and the Vishay parts are not.
It is also interesting that the TSOP1838 is a discontinued part. We used to use them where I work and have replaced them with TSOP2838 and/or TSOP4838. I might be able to get one of each to compare, if I ask nicely. The data sheet for the TSOP4838 gaves a range of 22m, vs 11m for the PNA4612. They may however be using different test methods.
Pat MacKenzie
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Old Feb 23, 2003, 12:59 PM
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Pat,

my PNA4612 are also from Digikey. The Vishay parts are the only ones that I can get from Conrad (sort of german Radio-Shack), but when one part gives me glitches and the other one doesn't then this is a good reason for spending the overseas shipping costs and paying the import fees.

What would be a reason for taking even more sensitive parts? Using fewer IR LEDs? I use 20 LEDs with a peak current per LED of 200mA and was about to go to 40 LEDs because of the glitches. This seems to be unnecessary now. The PNA4612 seems to be a good compromise for me, as my models are so small that I don't want them to fly more far away than 45m.

A good reason for choosing different parts would be a better ratio of sensitivity to proofness against different signals (ambient light, sunlight, fluorescent light, electrical noise). Any data about this?

Regards, Jochen
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Old Feb 23, 2003, 01:10 PM
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Oh, and by the way, the datasheet of the TSOP 1838 speaks about 35m transmission distance from a TSAL 6200 LED using 300mA, which does not happen in my experience.

How important is the 100 Ohm/4,7uF supply filter that the datasheet recommends? I have used the PNA4612 with such a filter but have used the TSOP 1838 without. I have connected that one directly to the output of a LTC1754-5 charge pump, whose output voltage might be influenced by the pulsed actuator current. This might have cut down the secure transmission distance. Perhaps I should try it again with such a supply filter.

Regards, Jochen
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Old Feb 23, 2003, 01:37 PM
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Quote:
Originally posted by jberg

A good reason for choosing different parts would be a better ratio of sensitivity to proofness against different signals (ambient light, sunlight, fluorescent light, electrical noise). Any data about this?

Regards, Jochen
If you go to the Vishay site :
http://www.vishay.com/ir-receiver-modules/
at the bottom right under general information they have some further information on this. Unfortunately it seems to be specific to the standard sort of codes used in home electronic remotes, so I think we need to do some of our own testing. Your results are certainly useful data.

Based on my reading of these the choice of the TSOP1838 is a poor one. They want a 15ms gap at least every 90 msec for the AGC circuit to work correctly. Our frame rate is 16msec, so there is no gap for the AGC to recover. Our transmitted pulses must look a lot like AC noise to the IR rcvr. Perhaps we should be changing the encoding scheme with the PIC in the transmitter (and the rcvr decoding) to more closely match standard remote signals.
This is based on a fairly quick review of the application notes. I am going to try to find similar information for the Panasonic parts.

Pat MacKenzie
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Old Feb 23, 2003, 01:46 PM
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Perhaps we can tell the PIC to filter out every fifth frame? Then we would have the needed gap every 80ms and are still able to use regular transmitters (which I prefer as it keeps things cheap and simple).

On the other hand, if it turns out that the PNA4612 does not need this gap, why not use this one?
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Old Feb 24, 2003, 01:41 PM
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Italy
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Koichi's IRXA202

Koichi,
I tried to visit your web site but I'm not able to show Japanese font. So can you tell how (if it's possible) I can modify IRXa202 's scheme and hex code to drive 2 actuators instead of one?

Regards,
Dario
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Old Feb 24, 2003, 01:58 PM
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Dario,

try reading Koichis page using http://babelfish.altavista.com !

Regards, Jochen
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