Author Topic: trasmitter and receiver question (Read 2611 times)

Metal Slug 2 · « **on:** January 28, 2009, 12:16:49 AM »

i have always wanted to make a custom ground vehicle robot that is controlled remotely by me and recently...

I found this inexpensive transmitter and receiver package here:

https://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=8337&Product_Name=Hobby_King_2.4Ghz_4Ch_Tx_&_Rx_(Mode_1)

and i was going to plan on buying it and using it to make a little remote controlled vehicle robot. however, the advertisement said "robot controlling hobbiests do not order!". This package was designed for use with model airplanes. Obviously it seems to me that receivers/transmitters used for airplanes should not be used to control ground vehicles.

My question is Why? ... and if i were to buy it and use it to control a ground vehicle robot, would it be really bad?

if i cant use the above package, does anyone know where i can get a transmitter/receiver package (or separate) for as great a deal as the one found in the link

fuzzyt · « **Reply #1 on:** January 28, 2009, 11:01:52 AM »

It might be because a lot of equipment in the home tends to operate at 2.4Ghz.

Common frequency for cordless phones, wireless networking, some security cameras, microwave ovens and who knows what else. This could cause a lot of interference to your remote control session. Otherwise I can't think of a real reason to not use it.

Razor Concepts · « **Reply #2 on:** January 28, 2009, 11:17:04 AM »

Yeah, that 2.4 technology they're using in that radio is probably the absolute cheapest they could have made it, so anything else in the 2.4 range will probably mess it up. Name-brand 2.4ghz systems are fine though, they do frequency hopping so nothing can interfere.

tristantech · « **Reply #3 on:** January 28, 2009, 08:20:35 PM »

I'm surprised that they say its for model airplanes because blocking interference is more critical for model airplanes

Razor Concepts · « **Reply #4 on:** January 28, 2009, 08:23:58 PM »

Generally planes are flown in big fields outside, away from interfering phones and such.

Metal Slug 2 · « **Reply #5 on:** January 29, 2009, 12:06:28 AM »

Alright. so it seems that my (wireless) phone would interfere with the signal from the transmitter. Would this work visa versa, would the controller effect my phone calls. if so, theres always this option, but I'm not sure if it is a name brand system and if it will interfere with different signals.

https://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=7882&Product_Name=DX5e_5Ch_Full_Range_TX_/_RX_only_Mode_2

i noticed there is two packages of the same thing, one is "Mode One" and the other "Mode Two" ....what is the difference between these two???

Thanks for the help.

Razor Concepts · « **Reply #6 on:** January 29, 2009, 04:13:07 AM »

Mode one has throttle on the right stick, and mode two has throttle on the left stick.

fuzzyt · « **Reply #7 on:** January 29, 2009, 11:15:55 AM »

Don't know how far you want to go with this, but you might be interested in zigbee modules. They are more inline with robotics design and allow you far more options than an RC controller.

Just google zigbee robotics and see what you come up with.

Admin · « **Reply #8 on:** February 07, 2009, 10:47:43 AM »

Quote

Obviously it seems to me that receivers/transmitters used for airplanes should not be used to control ground vehicles.

My question is Why? ... and if i were to buy it and use it to control a ground vehicle robot, would it be really bad?

Because your signal might interfere with someone else who is flying their plane.

Think what happens if your signal causes their plane to crash. Planes aren't cheap!

Or even worse, it crashes into expensive property, or someones face.

frodo · « **Reply #9 on:** February 07, 2009, 10:51:34 AM »

i've been looking for receiver boxes to build an ground R/C robot but i can't find any receivers that use ground frequency so should i just get a receiver box with air frequency and pray that nothing bad happens?

paulstreats · « **Reply #10 on:** February 07, 2009, 11:07:11 AM »

No.

for the reasons admin gave in his above post.

imagine that the forward signal on your robot put somebodies aeroplane into a nosedive and crashed it. would you be willing to pay the £2000+ for the damage you caused?

if you cant find a control unit the easiest solution is to buy a cheap radio controlled car and remove the reciever from it (along with motors and motor driver and keep the wheels and anything else scavengable)

Razor Concepts · « **Reply #11 on:** February 07, 2009, 12:26:48 PM »

There are pleny of receivers that use ground frequencies.. because there are plenty of people operating RC cars and trucks. They are everywhere - just look at towerhobbies.com . You can find 27mhz receivers for like $20-30 and 75mhz receivers for a little more. The latest and greatest technology is 2.4ghz, which cannot interfere with any other radio system (they have tested it by operating 100 2.4ghz radio systems and they did not intefere with each other).

Metal Slug 2 · « **Reply #12 on:** February 07, 2009, 10:59:26 PM »

Quote from: Razor Concepts on February 07, 2009, 12:26:48 PM

There are plenty of receivers that use ground frequencies.. because there are plenty of people operating RC cars and trucks. They are everywhere - just look at towerhobbies.com .

so i looked and i found this package...it includes a transmitter, 4 servos, a receiver, batteries.etc. Everything i need basically for a very good price...and you can choose a ground or air frequency crystal, so i should have no problems...4 channels is perfect...2 for driving and 2 for an arm and grabber.

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXEFJ4**&P=0#otheritems

Am i correct in assuming that i can use this for ground control if i order a 75MHz crystal with it

...and on another note, i was looking for the receiver which came with the package, but i could only find this one:

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLSX5&P=7

apparently this is an 8-channel receiver...why would they add an 8-channel recever to a package which has a transmitter with only 4-channels?

and one more thing $:-\$ ...i couldn't find out what the range of this thing was, where can i look to find it

Thanks for the help

Razor Concepts · « **Reply #13 on:** February 07, 2009, 11:11:11 PM »

The crystal comes with the radio system, so no need to buy one separetly.

Usually the difference between an 8 channel receiver and a 4 channel is just programming, so they decided to give you the most for your money and make it an 8 channel.

Range is roughly 1.5 to 2 miles line-of-sight in the air, so expect to get about 1 mile at best on the ground line of sight.

Joesavage1 · « **Reply #14 on:** February 08, 2009, 01:44:09 AM »

Quote from: Razor Concepts on February 07, 2009, 11:11:11 PM

The crystal comes with the radio system, so no need to buy one separetly.

However you could buy another (well a least with most remotes) in case you wanted more frequencies for maybe another robot you will make.

Joe

Metal Slug 2 · « **Reply #15 on:** February 08, 2009, 01:53:05 AM »

Quote from: Razor Concepts on February 07, 2009, 11:11:11 PM

The crystal comes with the radio system, so no need to buy one separetly.

Usually the difference between an 8 channel receiver and a 4 channel is just programming, so they decided to give you the most for your money and make it an 8 channel.

Range is roughly 1.5 to 2 miles line-of-sight in the air, so expect to get about 1 mile at best on the ground line of sight.

sorry, my wording was bad, it was misinterpreted. i know the package comes with the crystal, i was just questioning whether that crystal would be ok for ground control...and it is

Plus, i found that towerhobbies also has a used section...i found the same package (channel 65 - still ok for ground control

) selling for $90...used, but with no damage - the original cost is $130..so i would save $40..but should i risk buying the used package?

Joesavage1 · « **Reply #16 on:** February 08, 2009, 01:55:41 AM »

Hmm.. youve always gotta be careful when buying second hand but its probably OK although myself i wouldnt take the risk.

Joe

Metal Slug 2 · « **Reply #17 on:** February 09, 2009, 09:53:55 PM »

I was searching again and I came across this package:

1 - http://www.robotmarketplace.com/products/0-HRC156751.html

Would this package be better,worst or equal to the previous packages i stated??:

2 - http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXEFJ4**&P=0#otheritems

3 - https://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=7882&Product_Name=DX5e_5Ch_Full_Range_TX_/_RX_only_Mode_2

I'm thinking the second package is the best value because it comes with 4 servo's, but im not entirely sure (do these servo's rotate continuosely?). Or the 3rd package maybe is best because it has 5 channels and sells for ~$75 once you are a 'member' of their website (which I am). Which package is the best of all though, based on value and performance???

Thanks.

Razor Concepts · « **Reply #18 on:** February 09, 2009, 09:58:22 PM »

Agreed, second one is the best. Third is 2.4ghz which doesn't work as great on land, and the first one doesn't have many features.

Metal Slug 2 · « **Reply #19 on:** February 09, 2009, 10:18:33 PM »

Thanks Razor Concepts.

Would you by any chance know if the servos which come with the second package can rotate continuously?..i plan to build a small r/c car with this package and need the servos to rotate continuously.

Razor Concepts · « **Reply #20 on:** February 09, 2009, 10:24:24 PM »

All of them can rotate continuously, the modification process is just about the same as the Hitec 311 servos.

Metal Slug 2 · « **Reply #21 on:** February 10, 2009, 09:06:03 PM »

awesome, thanks.

unfortunately, towerhobbies feels like ripping the crap out of Canadians...they charge an extra $15 on shippings (to an original $10, so $25 total)...then we are susceptible to duty, border etc. taxes..probably another ~$15...AND now since $1 CAD = ~$.8 American...the overall total jumps to about $200 Canadian dollars...which at this time i can not afford.

Metal Slug 2 · « **Reply #22 on:** February 16, 2009, 12:08:02 AM »

I took another look at servocity.com and found this package:
http://www.servocity.com/~servo/html/laser_6_fm_ground_systems.html

and when i 'custom' make this package with 6 HS-322hd servos an 8ch Rx the 6ch Tx, a switch and battery holder the total comes to this:
http://www.servocity.com/cgi-bin/shopper.cgi?display

Is this a good deal?? or is the second package stated in my previous post still better?

Razor Concepts · « **Reply #23 on:** February 16, 2009, 10:59:20 AM »

Second link doesnt work, its one of those things you can't link. There isn't anything wrong with that system, so if you can afford it, go for it.

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Author Topic: trasmitter and receiver question (Read 2611 times)

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