Author Topic: UART communication range?  (Read 4207 times)

0 Members and 1 Guest are viewing this topic.

Offline izaktjTopic starter

  • Robot Overlord
  • ****
  • Posts: 216
  • Helpful? 0
UART communication range?
« on: April 20, 2008, 12:27:21 PM »
What is it's range?

Offline izua

  • Supreme Robot
  • *****
  • Posts: 682
  • Helpful? 0
Re: UART communication range?
« Reply #1 on: April 20, 2008, 01:30:28 PM »
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
« Last Edit: April 20, 2008, 01:32:37 PM by izua »
Check out my homepage for in depth tutorials on microcontrollers and electronics.

Offline izaktjTopic starter

  • Robot Overlord
  • ****
  • Posts: 216
  • Helpful? 0
Re: UART communication range?
« Reply #2 on: April 20, 2008, 01:35:31 PM »
I guess I'll need another telecommunication system for my UAV project. I want 1km at least.

Offline izaktjTopic starter

  • Robot Overlord
  • ****
  • Posts: 216
  • Helpful? 0
Re: UART communication range?
« Reply #3 on: April 20, 2008, 02:01:05 PM »
Suggestions?

Offline izua

  • Supreme Robot
  • *****
  • Posts: 682
  • Helpful? 0
Re: UART communication range?
« Reply #4 on: April 20, 2008, 02:08:02 PM »
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.
Check out my homepage for in depth tutorials on microcontrollers and electronics.

Offline izaktjTopic starter

  • Robot Overlord
  • ****
  • Posts: 216
  • Helpful? 0
Re: UART communication range?
« Reply #5 on: April 20, 2008, 02:17:30 PM »
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 ;)
« Last Edit: April 20, 2008, 02:30:13 PM by izaktj »

Offline Asellith

  • Contest Winner
  • Supreme Robot
  • ****
  • Posts: 648
  • Helpful? 9
  • "I'm a leaf on the wind. Watch how I soar"
Re: UART communication range?
« Reply #6 on: April 20, 2008, 02:37:24 PM »
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.
Jonathan Bowen
CorSec Engineering
www.corseceng.com

Offline izaktjTopic starter

  • Robot Overlord
  • ****
  • Posts: 216
  • Helpful? 0
Re: UART communication range?
« Reply #7 on: April 20, 2008, 02:46:27 PM »
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.

Offline Asellith

  • Contest Winner
  • Supreme Robot
  • ****
  • Posts: 648
  • Helpful? 9
  • "I'm a leaf on the wind. Watch how I soar"
Re: UART communication range?
« Reply #8 on: April 20, 2008, 06:31:24 PM »
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.
Jonathan Bowen
CorSec Engineering
www.corseceng.com

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,659
  • Helpful? 169
    • Society of Robots
Re: UART communication range?
« Reply #9 on: April 26, 2008, 05:25:06 PM »
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?

Offline izaktjTopic starter

  • Robot Overlord
  • ****
  • Posts: 216
  • Helpful? 0
Re: UART communication range?
« Reply #10 on: May 16, 2008, 08:04:58 PM »
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.

Offline superchiku

  • Supreme Robot
  • *****
  • Posts: 953
  • Helpful? 5
  • cooll
Re: UART communication range?
« Reply #11 on: May 16, 2008, 11:10:42 PM »
if u want to do uav u need to use gps and autopilot first gather some indo abt it
JAYDEEP ...

IT AND ROBOTICS ENGINEER

"IN THE END IT DOESNT EVEN MATTER"

Offline Nyx

  • Robot Overlord
  • ****
  • Posts: 204
  • Helpful? 0
Re: UART communication range?
« Reply #12 on: May 17, 2008, 05:37:24 AM »
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 ;)
« Last Edit: May 17, 2008, 05:45:30 AM by Nyx »

Offline benji

  • Supreme Robot
  • *****
  • Posts: 832
  • Helpful? 0
Re: UART communication range?
« Reply #13 on: May 17, 2008, 06:22:33 AM »
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,,

good ol' BeNNy

Offline Nyx

  • Robot Overlord
  • ****
  • Posts: 204
  • Helpful? 0
Re: UART communication range?
« Reply #14 on: May 19, 2008, 02:16:43 PM »
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.

Offline Asellith

  • Contest Winner
  • Supreme Robot
  • ****
  • Posts: 648
  • Helpful? 9
  • "I'm a leaf on the wind. Watch how I soar"
Re: UART communication range?
« Reply #15 on: May 19, 2008, 03:34:18 PM »
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
Jonathan Bowen
CorSec Engineering
www.corseceng.com

Offline benji

  • Supreme Robot
  • *****
  • Posts: 832
  • Helpful? 0
Re: UART communication range?
« Reply #16 on: May 20, 2008, 03:32:16 PM »
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

Quote
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
good ol' BeNNy

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,659
  • Helpful? 169
    • Society of Robots
Re: UART communication range?
« Reply #17 on: May 25, 2008, 01:17:27 PM »
For crazy distances like that . . . you should use the internet to transmit the data . . .

Offline izaktjTopic starter

  • Robot Overlord
  • ****
  • Posts: 216
  • Helpful? 0
Re: UART communication range?
« Reply #18 on: May 25, 2008, 02:13:56 PM »
Wouldn't the communication speed be to slow?

Offline Brandon121233

  • Contest Winner
  • Supreme Robot
  • ****
  • Posts: 320
  • Helpful? 0
  • "Genius is %1 inspiration and %99 perspiration"
Re: UART communication range?
« Reply #19 on: May 25, 2008, 02:20:18 PM »
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
Hell, there are no rules here—we're
   trying to accomplish something.

                                                                              —Thomas Edison

 


Get Your Ad Here