Radio Link 2.4GHz Tx & Rx

[RogueTwoRobots]

Hi guys,

Found this link over on the Robotwars101.org forum. It's a 4 channel transmitter and receiver kit on 2.4GHz for £25.48:

http://www.giantcod.co.uk/gianitcod-24g ... 03779.html

Peter Waller has ordered one to do some testing on and see how it fares, but after reading reviews on the website (average rating 4.91 out of 5) I have ordered myself one too. It came to just over £28 to have it delivered first class insured.

I will be testing it in both Carcinus and Drumroll to see how it performs and to see what it is like with failsafes. According to the site it sounds like it behaves in a similar manner to the Planet 5 kit in that upon loss of signal it continues giving out the last known good pulse for a second or two then cuts all signal and outputs nothing. The 6ch receiver case looks a lot more sturdy than the Planet 5 one. It's very similar to the Futaba 2.4GHz receiver, except it has one aerial instead of two. The transmitter is effectively an old Skysport 4 shape, with cheap metal coverings bearing the Radio Link logo etc. Anyone who has seen my Skysport 6 though will know what I've got in mind for mine

The reviews say range and reception is excellent; it has got a CE marking so doesn't exceed 100mw (although I believe the exact RF output is unknown). I ordered mine with a minimal guarantee, meaning that if it is defective on arrival I can get a replacement/refund but if I break it in use I can't. That's why they can offer it at such a low price apparently. You can pay extra (not sure how much) to have a normal guarantee period incase you do break it within the first however many months though.

It's got the usual channel reverse switches, but no dual rates. Also has V-Tail/Elevon mixing built-in, and a charging socket if you wish to use rechargeable batteries. No instruction book, no fancy packaging. Just cheap and cheerful
Will let you know how it performs.

[joey_picus]

Re: Radio Link 2.4GHz Tx & Rx

Anyone who has seen my Skysport 6 though will know what I've got in mind for mine

I take it you found some more blue metallic paint then

Good luck with the testing though, hope it proves to be worth all the praise. 2.4ghz seems to be getting cheaper and cheaper now, if only I'd waited for this before spending £300 on a DX7 :P heh.

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

I take it you found some more blue metallic paint then

No, not yet sadly. I was just meaning painting it in general to look a bit better than how it comes, but I've got a little bit of blue metallic left and Drumroll's fully painted so I guess it might as well be metallic blue

A quick eBay search pulls up several DX7s going for £200+ for transmitter only, if you wanted to sell and buy cheap. But looking at the pics on eBay at least it's a pretty sexy looking transmitter

[beast]

Re: Radio Link 2.4GHz Tx & Rx

[quoteA quick eBay search pulls up several DX7s going for £200+ for transmitter only][/quote]
yes but Joey must have brought one ages ago

and its like pc stuff comming down all the time

ps you realy need a 5 chan so you can use a WEAPON (ban boxes)

[psycho_fling]

Re: Radio Link 2.4GHz Tx & Rx

you dont need 5 channel for weapon robot with this tx you could have 2 weapons

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Yeah the minimum you need for a weapon is 3ch. Drumroll's drum is on Ch3, if I had a self-righting arm on it, it would be on Ch4.
Personally I find Ch5 to be a bit restrictive for some weapons as the switches tend to be On-Off, or fwd-bck with no middle ground. Obviously you could replace this with an On-Off-On switch or an adjustable dial if you wanted to but that's hassle :P
I know some spinners use the switch if the weapon is just relay-controlled, but for electric axes/lifters, I would find it much more flexible and controllable on a stick channel. What do flippers tend to use? Can you just get by with flicking the switch on to activate the valve and then rely on the elastic to retract the flipper plate?

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Received the item today. As mentioned on the website, no fancy box, just packaged in a sturdy jiffy bag. May sound a bit minimal for a transmitter but there was strong foam packaging surrounding the sticks to prevent damage, the aerial was folded down and the whole thing was wrapped in an extra layer of bubble wrap.

The transmitter. Metal trim isn't quite as tacky looking as I was expecting but I'm still gonna paint it I reckon

[attachment=2:39t7u8dq]DSCN4829.JPG[/attachment:39t7u8dq]

Mixing switch, a bit fiddly to get to but it's mixing nonetheless

[attachment=1:39t7u8dq]DSCN4833.JPG[/attachment:39t7u8dq]

The receiver, pretty sturdy case

[attachment=0:39t7u8dq]DSCN4834.JPG[/attachment:39t7u8dq]

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Bind button (circled in red)

[attachment=0vobhvwj]DSCN4835.JPG[/attachmentvobhvwj]

Transmitter gets turned on, receiver powered up and then this button is pressed. Should take a few seconds apparently.

I've not had the chance to try it out yet but will be home this weekend so will see how it performs. The battery bay will accept 8xAA batteries but the two leads connected to the positve and negative terminals can be cut and have a plug fitted on them so a typical rechargeable back can be fitted instead. I'm assuming the charge socket will just function as normal then but again, I will investigate this weekend.

There is also a space in the battery bay to carry a spare set of cryst......oh, wait

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Okay, home for the night so had a chance to set up the Radio Link set. First up was mods; in this instance, all that consisted of was removing the metal springs in the battery bay for holding AAs in place so I could fit a standard rechargeable pack and then fit a Futaba plug on the transmitter battery leads so that I could plug the battery in. Job done. I also removed the trainer jack while I had the thing apart since I don't need it. Plus I pulled off a couple of the metal sticker coverings just for the hell of it

Right, so I fired it into Carcinus and powered up the transmitter and receiver. Green LED came on in the receiver. I pressed the bind button on the receiver until the LED started blinking then let go. Blinked for about two seconds then returned to being constantly on. Bind complete. I had control over the motors and the response was very positive. I then tested its failsafing abilities; I have two Electronize 30A controllers with built-in failsafes and a 15A controller with an external failsafe. All systems failsafed correctly. I didn't check it actually without having a failsafe plugged in but I'm assuming it gives out no signal after the transmitter has turned off. Whether that means you don't need failsafes, I don't know (I don't think it does) but I will try it out tomorrow and see.

Next up I tested the mixing, all worked fine. There only appears to be one setting though so I don't know if it's Elevon or V-Tail (when using an external mixer we're always told to buy a V-Tail one but on my old Hitec remote I had to set it to Elevon for the mixing to be correct) but whatever it is it allows both drive motors to be controlled from the one stick, so suitable for the bots.

I haven't performed a long-range test yet (will be doing so tomorrow) but from driving it around my room I am really happy with the way it performs. Glitch-free control, no signs of interference - which is nice considering I could barely control the robot in my room with the 40MHz system - all in all I think I'm becoming a bit of a 2.4GHz fan
I know it's just masked the sources of interference rather than removing them but for keeping things low-cost and simple, it's a really good solution.

So unless anyone has any major issues with it, I would say this unit is suitable for our use. I will give it a long-range test tomorrow and then it'll get a thorough testing at Barnsley.

[leorcc]

Re: Radio Link 2.4GHz Tx & Rx

Have you had a chance to test it with other 2.4GHz transmitters in the area to check for interference?

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Ah good point Leo! I have not been able to test this yet, so maybe some sort of testing can be arranged at Barnsley when there are other 2.4GHz units about. Thanks for mentioning that.

Tested Carcinus yesterday with it and got excellent range on it - not sure of the exact distance in metres but definetly sufficient to cope with robot events.

[john_frizell]

Re: Radio Link 2.4GHz Tx & Rx

I've also purchased one of these and a couple of receivers. Tried the failsafe by turning off the transmitter while it was driving a motor and it worked fine although it took a second to kick in, unlike my 40 MHz which kicks in instantly. But a one second delay is perfectly acceptable for a robot in an arena. It also takes a second or so to start up when the transmitter is switched back on.

[muchalucha]

Re: Radio Link 2.4GHz Tx & Rx

I read up that the planet 5 system uses new cheap internals, could someone break there's open and take pics , id be really interested to see if the innards are the same.

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Crack open a Planet 5 or crack open one of these Radio Link ones? I've got a picture or two of the internals of the Radio Link system that I could upload in the morning but it's very simple. One circuit board fitted down the bottom of the transmitter casing; the sticks, LED and battery connections just plug in to it, there is a PIC chip or two, and a small circuit board that seems to be the 2.4GHz 'module' stacked on top of it (similar thing is fitted in the receiver)

So yeah it's pretty simple. Been a while since I took my Skysport 6 apart but I remember there being L shaped circuit boards fitted round the sticks and everything on that one, but for the price you pay for a Radio Link unit the level of simplicity is no surprise.

[muchalucha]

Re: Radio Link 2.4GHz Tx & Rx

is the 2.4 ghz board a sort of small triangle with platish edges?