Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: izaktj on April 20, 2008, 12:27:21 PM
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What is it's range?
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give us more info.
going on +5 TTL signal levels, i'd say a few meters. Using RS232 voltage levels, you might reach a few tens of meters, as the standard is intended. i'm able to get data carried ~20 meters inside my house (over cat5 cable) at 9600 using RS232 levels
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I guess I'll need another telecommunication system for my UAV project. I want 1km at least.
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Suggestions?
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don't do something over your head. UART is (genneraly accepted in hobby use as) tethered RS232, i'm sure you don't want a wire dangling out of your flying thing, and a big hook of wire at the other end.
there are other wireless communication protocols. look into the GSM suite - CDMA, GPRS. or build your own radio protocol.
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don't do something over your head. UART is (genneraly accepted in hobby use as) tethered RS232, i'm sure you don't want a wire dangling out of your flying thing, and a big hook of wire at the other end.
there are other wireless communication protocols. look into the GSM suite - CDMA, GPRS. or build your own radio protocol.
Thanks, I'm googleing them right now.
BTW any links and info would be greatly appreciated ;)
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1 km is really long but some protocols will work at that range. Or you can get RS232 extenders relatively cheap. Our Telecom guys use them to get rs232 signals to travel over a mile on twisted pair. If you get a twisted pair cable and use an extender you could do it. Hmm most need to be powered but it's just a DC input so you might be able to put them on batteries. The unpowered ones have lower ranges. If you look hard enough you might be able to find one that could be powered at one end and unpowered at the UAV end.
The other option is like RS485 or RS422 those both have longer ranges and you can get RS485/422 to 232 converters easily. Might even be able to find a TTL level to RS485 converter to cut down on cost a bit.
Just a note on protocols. UART is a communication protocol. RS232/485/422 are all transmission protocols. You can easily use more then one transmission protocol without to much processing going on but to use more then one communication protocol things get crazy. Like to transmit with UART and Receive with I2C.
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1 km is really long but some protocols will work at that range. Or you can get RS232 extenders relatively cheap. Our Telecom guys use them to get rs232 signals to travel over a mile on twisted pair. If you get a twisted pair cable and use an extender you could do it. Hmm most need to be powered but it's just a DC input so you might be able to put them on batteries. The unpowered ones have lower ranges. If you look hard enough you might be able to find one that could be powered at one end and unpowered at the UAV end.
The other option is like RS485 or RS422 those both have longer ranges and you can get RS485/422 to 232 converters easily. Might even be able to find a TTL level to RS485 converter to cut down on cost a bit.
Just a note on protocols. UART is a communication protocol. RS232/485/422 are all transmission protocols. You can easily use more then one transmission protocol without to much processing going on but to use more then one communication protocol things get crazy. Like to transmit with UART and Receive with I2C.
Thanks a lot. Know I see more clear.
What if I wanted 60km? Is there a way to use the same "kind" of communication as cellphones have? Like controlling the UAV by cellphone calls? Is this possible? Thanks.
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Cellphones are an option there are many out there. I personally have experience with the Blue Tree BT-4200. SparkFun sells a module by telit but that uses GSM (A.K.A At&T, Cingular, T-Mobile, and some others) The BT-4200 uses CDMA (Verizon, Altell). The Telit module is really nice. I found some modules that are built with the telit ones that Sparkfun sells. They are really nice. http://secure.conwin.com/cgi-bin/store/cp-app.cgi?usr=51H7391114&rnd=1314897&rrc=N&affl=&cip=70.196.86.254&act=&aff=&pg=prod&ref=47091&cat=&catstr=
This one has GPS in it and even some GPIO pins so you can monitor more things or control some stuff. You have to watch with the units Janus sells because some are not licensed to work in the US. I think that was just the CDMA versions or the Python ones. The ones with Python are really cool. They could be used as a limited but functional controller. Has a bunch of GPIO pins and some ADCs. But Cellular is an option.
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A 'repeater' is a device used to accept a weak signal, clean it and boost it, then retransmit it. They are useful for long distance transmissions.
For 1km, sounds like you need a high powered transmitter. If you are going wireless, you'll need a license. I have one, basically you study for a few weeks, take a test, and wallah they give you a card.
What kind of data are we talking about?
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A 'repeater' is a device used to accept a weak signal, clean it and boost it, then retransmit it. They are useful for long distance transmissions.
For 1km, sounds like you need a high powered transmitter. If you are going wireless, you'll need a license. I have one, basically you study for a few weeks, take a test, and wallah they give you a card.
What kind of data are we talking about?
Video and text.
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if u want to do uav u need to use gps and autopilot first gather some indo abt it
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Wifi is rated at 95m for line-of-sight transmission... With a good antenna, and perhaps a tiny bit of amplification... You might be able to reach 1km. I know someone who's exceeded that ;)
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mmm i was thinking ,, why dont u use 10 rf modules, each one is rated for 100 meters maximum range(operating at 12 volts)
so using 10 you get 1 km ,,plus its wireless...the problem is that you have to put these stuff in some secure places and provide 12 volts all time,,
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mmm i was thinking ,, why dont u use 10 rf modules, each one is rated for 100 meters maximum range(operating at 12 volts)
so using 10 you get 1 km ,,plus its wireless...the problem is that you have to put these stuff in some secure places and provide 12 volts all time,,
I don't think that will work... They would just interfere with one another. But like I said, you could just amplify the signal of one single module.
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it would work with some crazy programing on each of the modules and building your own transmission protocol. Or changing frequencies with each step then matching transmitter and receiver but each module would receive at one frequency and transmit on another.
Syncing all the information down the chain would work if the receiver takes in data then sends it out byte by byte and the originator pauses for one byte after each transmission. Would turn into a headache
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it can work by using some addressing bytes before sending data
like this
station num 1 is A1A1A1..data..terminator
station num 2 is A2A2A2..data..terminator
would work if the receiver takes in data then sends it out byte by byte and the originator pauses for one byte after each transmission.
i think it would work this way
the byte transmitted from station 1 need 1 sec to arrive to station 2
.....etc
then just ignore data the first 10 secs then read it byte by byte
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For crazy distances like that . . . you should use the internet to transmit the data . . .
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Wouldn't the communication speed be to slow?
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Check this shield out for the arduino that lets you use GPS and GPRS http://www.libelium.com/tienda/catalog/product_info.php?cPath=21&products_id=42 (http://www.libelium.com/tienda/catalog/product_info.php?cPath=21&products_id=42)