Radio Link 2.4GHz Tx & Rx

[peterw]

Re: Radio Link 2.4GHz Tx & Rx

Just a couple of things to add.
I have found that if there is another 2.4Ghz tranmitter operating within about 300 mm of the receiver when the system is switched on the receiver never seem to lock on to the transmitter. This is in normal operation not binding. If the other transmitter is switched off or moved further away control is established and then placing the transmitter back in close proximity to the receiver has no effect. Not a major problem but I was doing some tests with other transmitters to check the operation and thought the system had stopped working.
The other thing is the failsafe as stated above all four channels stop outputting pulses when the signal is lost so you are reliant on the speed controllers for failsafe. On the throttle channel when the signal first connects or reconnects the receiver outputs the minimum 1ms pulses until the throttle stick is placed in that postion then the pulses follow the stick. Strangely that is stick full forward as standard so you need to reverse the throttle channel.
All round I am most impressed for a £15 Transmitter and a £10 receiver.
Receiver size and weight are a little high for ants but as the receiver is 12.5gms and its case accounts for 6gms there are ways to reduce it.
The RF part of the receiver is on a tiny daughter board 23 x 15mm see picture:
http://i109.photobucket.com/albums/n66/ ... MG0922.jpg
I am looking at the possiblity of building a dual controller board that sits on the servo connector pins and fits within the existing size of the receiver.
I will need to replace those two large capacitors.

[peterw]

Re: Radio Link 2.4GHz Tx & Rx

I now have a working antweight controller running.
Here is the receiver insides as it comes.
http://i109.photobucket.com/albums/n66/ ... MG0922.jpg
I have managed to replace the two large capacitors with small surface mount devices and removed all but 5 of the pins and turn the arial and it still works.
http://i109.photobucket.com/albums/n66/ ... MG0937.jpg
The built up board looks like this:
http://i109.photobucket.com/albums/n66/ ... MG0939.jpg
Fully finished it looks like this with a standard receiver next to it:
http://i109.photobucket.com/albums/n66/ ... MG0942.jpg
Original Receiver....... 44 x 30 x 17mm and 12.7 gms
Controller Module...... 42 x 27 x 11mm and 11.5 gms

[john_frizell]

Re: Radio Link 2.4GHz Tx & Rx

Nice job. Very impressive.

[peterw]

Re: Radio Link 2.4GHz Tx & Rx

I asked the chap at Giantcod if he could confirm that the RadioLink gear has CE approval and if he could publish the documantation and got the following reply.

Yes I can confirm it.
I will put all the cerficates on the site later.
Regards,
Rob.
www.giantcod.co.uk

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Used the Radio Link Tx/Rx combo in Carcinus for a fair few fights at Barnsley at the weekend.

In general, in performed very well. The robot failsafed without any problems both on the bench and in the arena. Signal wise, there were no problems in the arena, full control was retained for the duration of all its fights.

However, the issue Peter describes above of the transmitter and reciever not conecting when turned on in close proximity to other 2.4GHz sets occured during arming-up in one battle. We tried turning it off and back on again several times but signal couldn't be established. We removed the robot from the arena and tried again when it was on the pit bench (away from all the other active 2.4GHz sets) and it connected fine.

There are two or three ways I can think of to get round this:

1) Use a seperate Rx battery supply (i.e. not a BEC) and turn on the transmitter/receiver when you first take your robot into the arena (before everyone else turns their transmitter on). This way your tx/rx can connect without interference yet there is no risk of your robot's drive or weapon moving due to the fact that the link still needs to be plugged in. We did this for the fight after we had the connection problem and it worked fine.
2) Wait till everyone else has turned on their transmitters (and keep a bit of distance between your robot and others) and then turn on your transmitter.
3) Possibly a bit of a hassle, but mount your receiver/design your robot in such a way that you have a small access hole through which you can stick a thin screwdriver to press the bind button on the receiver and renew/re-establish the connection if needed.

This issue may sound rather troublesome but hopefully this shouldn't happen every time you arm up. It only happened during one battle out of six over the weekend for us; I guess it just all depends on the circumstances at the time.

That aside, for £25 it performed rather well and is a nice option for those just starting out building a robot in need of a transmitter/receiver.

Just to add too for anyone who's not had a look round the site, GiantCod also have a 6ch version for £52:

http://www.giantcod.co.uk/giantcod-24gh ... 03852.html

It is computer programmable and looks very similar to the Field Force 6 in terms of its buttons etc.

Also, for those who use Deans connectors, they sell ten pairs for £4. They're not actual Deans but an equivalent make and according to reviews, they work very well on their own or used with proper Deans conenctors. A nice money-saver:

http://www.giantcod.co.uk/deans-style-u ... p-208.html

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Forgot to add, I ran Drumroll in a busy whiteboard at the weekend on 40MHz. The robot has no suppression components fitted. I think every other robot in the fight was on 2.4GHz and I wasn't aware of suffering intereference at any point throughout that fight.

The rules change in 2011 for featherweights so it probably doesn't matter too much but based on this (and I know it's only one case, so not very conclusive) the 2.4GHz units aren't drowning out the 40MHz users.

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Copied from the antweight forum, a copy of the CE certificates. There was some doubt cast over the legitimacy of the CE marking on the transmitter:

http://www.giantcod.co.uk/forum/downloa ... &mode=view

Not sure why the CE marking on the actual transmitter is different from the way it's supposed to look, but it seems correct on the certificates.

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Sorry to dredge up an old thread but just got a point to mention and a question to ask:

The effects described above about the tx/rx not connecting when switched on while other 2.4GHz units are being powered up in close proximity occurred again at Edinburgh. It was the first fight and I had forgotten to turn on the tx and rx switches before everyone started powering their Spektrum units up. For all the following fights I took this approach and there was no problem.

After the end of the last fight though, I powered the robot up just to check everything was still running and once again I had the problem of the tx/rx not detecting each other. This time there were no other 2.4GHz units in use, and even once I was home and tried it again, the same thing happened. I've tried re-binding it and using different receiver battery packs etc but still no luck. I haven't had time to thoroughly try and diagnose the problem, but I'm beginning to think that this is a problem that I don't want happening during something like an important UK champs fight, so I'm looking to get a different 2.4GHz unit as part of the new Drumroll build.

My question is, for those of you using the Planet 5 systems, has this sort of problem ever occurred during the arming up phase in a battle? Or am I better off just spending a bit more on, say, a DX5e and getting a reliable connection?

Thanks

[widow_twanky]

Re: Radio Link 2.4GHz Tx & Rx

Sorry to dredge up an old thread but just got a point to mention and a question to ask:

The effects described above about the tx/rx not connecting when switched on while other 2.4GHz units are being powered up in close proximity occurred again at Edinburgh. It was the first fight and I had forgotten to turn on the tx and rx switches before everyone started powering their Spektrum units up. For all the following fights I took this approach and there was no problem.

After the end of the last fight though, I powered the robot up just to check everything was still running and once again I had the problem of the tx/rx not detecting each other. This time there were no other 2.4GHz units in use, and even once I was home and tried it again, the same thing happened. I've tried re-binding it and using different receiver battery packs etc but still no luck. I haven't had time to thoroughly try and diagnose the problem, but I'm beginning to think that this is a problem that I don't want happening during something like an important UK champs fight, so I'm looking to get a different 2.4GHz unit as part of the new Drumroll build.

My question is, for those of you using the Planet 5 systems, has this sort of problem ever occurred during the arming up phase in a battle? Or am I better off just spending a bit more on, say, a DX5e and getting a reliable connection?

Thanks

Jamie,

Planet 5 has always worked fine for me with absolutely no issues with respect to binding and the like. What I do dislike about it is the way it is bound. You press the button and turn the tx on with no other action needed. This means if you get a scenario where you press your button and someone else turns their tx on, your robot is under their control. A lot less likely when you have to pull a bind switch.

Also I read that the throttle channel fails safe to the position your turn it on at. I've not tried this but something to consider when using the throttle for the spinner.

Anyway, have found the planet 5 to be a fantastic little set but hopefully someone will have looked at the issues I've raised. Personally though I would want digital trims for anything which is as nasty as drumroll because everything then turns on how i want it to without any chance of me making a mistake.

Andy

[RogueTwoRobots]

Re: Radio Link 2.4GHz Tx & Rx

Thanks for the info Andy. The binding issue you described can happen in a similar way with the Radio Link sets. You power up the tx then press a bind button, so if any other Radio Link tx is on in the vicinity there is a chance that the receiver will bind to another unit. I guess it's just a potential risk associated with cheap 2.4GHz units.

Had a bit of trims discussion at Edinburgh actually. Liam's robot was always moving when the link was plugged in and it took a while to realise that the trims were miles out; it couldn't be seen because they were digital. I said then that I prefer mechanical trims because you can see where they are positioned, but I hadn't considered the benefit of digital trims that you have mentioned.
Common sense would dictate that you check all your stick positions and trims before powering things up but we all know most of us never do. I tend to just assume that they will be set in the position I left them in, which is a habit I should probably try to break. I always try to position my robot in such a way that the wheels are off the ground during arming up, just in case of offset trims and the locking pins help out in the event of weapon trim offsets. I guess seeing the mechanical trims having been knocked out of place is fine, the only problem I find after that is trying to remember what position they should be in!

[elobire]

Re: Radio Link 2.4GHz Tx & Rx

the support on giantcod is terrible, my reciever is broke and after creating a support ticket i have had no reply in 48 hours.
going to phone them later.

[peterw]

Re: Radio Link 2.4GHz Tx & Rx

I am suprised at that when I thought I had a problem with a receiver they were very quick to respond something I didn't really expect on such a low cost item.
Mind you 48hours from your post means you complained Saturday lunch time so they probably didn't pick it up until this morning.

[elobire]

Re: Radio Link 2.4GHz Tx & Rx

I am suprised at that when I thought I had a problem with a receiver they were very quick to respond something I didn't really expect on such a low cost item.
Mind you 48hours from your post means you complained Saturday lunch time so they probably didn't pick it up until this morning.

your probably right, i think il wait another day.
EDIT: just got a email, have to send the receiver and trasmitter back for testing.

[peterw]

Re: Radio Link 2.4GHz Tx & Rx

Before you do that have you checked that you have bound the transmitter and receiver together correctly.
See procedure cut from their site.

The bind procedure is the easiest, quickest, no fuss seen to date, this is done by powering up the transmitter and receiver, then a tiny button positioned at the end of the receiver case is pressed once. A green LED flashes for a second or so then stops, that€™s it, job done!

[elobire]

Re: Radio Link 2.4GHz Tx & Rx

Before you do that have you checked that you have bound the transmitter and receiver together correctly.
See procedure cut from their site.

The bind procedure is the easiest, quickest, no fuss seen to date, this is done by powering up the transmitter and receiver, then a tiny button positioned at the end of the receiver case is pressed once. A green LED flashes for a second or so then stops, that€™s it, job done!

tried that, i did have it working fine before. not sure why it broke.