Okay, so we have a problem every day. (If you’re not familiar, I’m making a full-size RC car). This time, it’s with the radio system. We can control everything just fine when we use the tether, but as soon as we try to use the radios, nothing works.
We are using RS-422 Data Modems (of the IFI screamer variety) as it says to. On the RC, it blinks “No Data/Radio” and both the Rx and Tx radios have “standby” lit up.
What are some areas we might want to check on? Potential problems?
Thanks,
ARP
Check the team numbers on both the RC and OI. They must be the same in order to function via radio. They are set in binary via dip switches on the lower right hand corner of both pieces. Shouldn’t matter what the number is, as long as they are the same on both sides.
We have already coordinated the team numbers. We are using the 2001 RC and OI by the way. Do we need to set the channels for the data modems or do they coordinate/program automatically? They are both on standby. Can you set one to receive and one to transmit or should they do it themselves?
Everything seems to be set up the way it dictates in the reference guide. Can anyone think of any reason(s) why they are not working?
try making sure you are using the right radio for each componet…the one with the opperator interface has a metal antenia, and the one for the robot controler has a hard rubber one.
yes, we have that set up correctly. The DB-9 work for the tether and for the program ports, is it possible that the same cables will not work for the RC-422 ports?
I think the same cables that work for the tether and program will work for the radio too (on 2000-2003 systems).
There are (at least) two different types of radio modems. One pair is used for communication between the Robot Controller and the Operator Interface. The other pair, which I believe is labeled “Ewave Screamer,” is used for remote programming and debugging. If your radios say “Ewave Screamer” rather than “Innovation First” in big white letters, you probably have the wrong radio.
That’s the only potential problem that I can think of at the moment from what you’ve said…good luck!
ewave used to make the radios for innovation first and the programing was just an extra feture but i am almost positive that they still worked as regular radios…
on a side note innovation first bought out ewave because they were not happy with the quality control of the product so it is possible that they radios are just bad…try asking the team you got them from for another set the ones from 02 and 03 should work the same
IFI bought the patents and information and designs of EWAVE but EWAVE the company is still around and they do some of the manufacturing still. If i remember correctly from what i remember is that the 2001 radios (i think) was the first year you needed the radios to be the same years models together. What i would suggest is to make sure that they are the 2001 radios and are the right set. The radio style changed from 300 something to 422’s in 2002 or 2003 so you may not have the correct radio set in the firmware. i would suggest to contact ifi to get the specs on the legacy system and modems to make sure all your hardware is compatable and correct.
Arpus-
Could you discribe the situation a little more in depth? Specificly, were physicly are the radios in relation to eachother? Do they have a clear line of sight to eachother? Is one close to the car frame? Are they both out on a test bed?
Also, what are you using for the OI’s power supply? It should output 9volts 1500mA. Using underrated supplys will get all the lights to blink and look healthy, but the radios may not have enough power to communcate. In anycase, range will be severly affected.
If you have not done so already, place both radios a few feet apart with a clear line of sight. If they do not manage to establish a link within 10 to 15 seconds, they are probably damaged (most 'bots manage to link up under 3 seconds).
Check that the power supply is adequate, both radios start with a clear line of sight and that both are placed away from anything that could be ‘noisy’. I susepect that a car frame could present a serious problem with communication. I would strongy suggest that you place the reciver high up and away from the rest of the car if feasible.
-Andy A.
Do you have a dongle on your OI. I know there is a pin, when activated deactivates your radio.
We were using a 9V AC adaptor to power the OI, which would seem to be enough (we don’t have the original AC adaptor included with the OI, but I believe it was a 9V adaptor). Is it possible that we should use something with MORE voltage, such as a 12 or 15 volt adaptor?
However, the OI says “Low Battery” while using the bootleg 9V adaptor that we found lying around.
Also, we tried setting the receiver and the transmitter up within a few feet of one another, and yet they still didn’t work.
What is a dongle? That sounds funny. In any case, I doubt we have one.
ARP
Just a question a little OT. Your profile says your not on a team now, were you ever on a team and if not what team is this control system borrowed from?
You need to use the provided AC adapter. I believe the OI requires 1.5 amps at 9 or 12 VDC (not 100% sure which), most “wall-wart” transformers can’t provide this. This would explain your radios not working properly. I’ve seen OIs only partially light up and do all sorts of wierd things when they aren’t getting enough juice.
What is a dongle? That sounds funny. In any case, I doubt we have one.
They are referring to something that plugs into the competition port on top, which would be used to change channels, disable the robot at a competition, etc.
Arp
I think your problem may be two fold.
First- the adapter must be 9 volts. Anything higher and you risk damage to the OI. It also should put out 1500mA (1.5 amps). You can check this fairly easily. On the wart it’s self, it should have a label. On this label, look for what ever comes after ‘Output:’. It should read something like '9VDC 1500mA. If it is less then this rating, then the OI will work, but the radio will probably not have enough juice to really transmit at the level needed.
Secondly. You mentioned that the low battery light is on. If this light is one when you are teatherd, then your RC is probably not getting enough power either. That light comes on when the RC’s voltmeter drops to a certain level. This value can be changed int he program, but I think it defaults to 10 volts. Usally this doesn’t cause radio problems, but I have noticed it can crop up when using a very old battery or if there is a bad connection between the RC and the battery. How is the RC being powered? Did you end up powering through the cars 12volt system? Did you ever check the quality of that power? It may not be adequate. If this is the case, then your RC radio may not be fully powered, which could result in the same symptom. Check the voltage at the RC’s power terminals with a voltmeter. It should read right around 12v, give or take 2.
-Andy A.
Alright.
The 2001 Innovation First-provided Radios (in the kit) were RS422 EWave Screamers. They are labelled similarly to the 2004 radios, except most of the blue text on the 2004 radios were red on the 2001 sets. The remote programming radio was the called the Stamper, if I recall correctly. Very few teams I know of purchased them, as they were expensive.
I would test the radios on another set of Operator Interfaces and Robot Controllers. Also, the antenna wire inside the OI radio has come loose on two of the 2001 radios I have looked at. Take a look there as well.
Good luck.
here if you want you can buy the stamper and accessories here, but please only purchase these items if they are going to be put to proper use, as they can cause interferance with other products…
Our original setup:
When we did this, the radios both had the “standby” LED lit up and there did not seem to be any transmission. “Valid Rx” was not lit up, and the “No radio modem” led was blinking, i believe (i dont have the materials in front of me right now). In any case, the radios were not getting any sort of signal.
The transmitter’s antenna IS broken (read: snapped off) about half way up. I assume this will have adverse effects on the range and reliability, but I would assume it would still be able to communicate with a receiver that is only 2 feet away and in direct line of sight. Perhaps not?
To answer a few questions:
We were originally going to power the RC through the car’s battery, but when we plugged it in, it continually turned on, then shut off, then turned on, then shut off, etc. Obviously, this was unacceptable, so we are going to power it with a separate 12V battery that seems to power it well. With this set up (and using a tether) we can operate motors and the such nicely!
I am not on a team and never was on one, believe it or not. Everything I know about robots and control systems and the sort (that is, not much) I picked up in the last week. We borrowed the equipment from team 571 which is the team at our school, Team Paragon at Loomis Chaffee in Connecticut.
And, finally, an update:
We located the gas cable which, we found, was much harder to cut than expected. But, after a lot of using wire cutters and pulling (we even used pruning loppers and an electric drill!) we finally cut the resilient cable and hooked it up to our servo. We mounted the servo more-or-less securely under the hood and hooked it into the RC. Using a tether, we were able to pull the throttle cable and rev the engine by tilting the joystick forward! Very exciting! Clearly, we will not take the car out of the garage until all systems are working (and the radio problems are solved). Still, it is somehow very gratifying to rev the engine with a joystick!
ARP
This is probably the problem. Try to find a fully rated adapter, probably from your schools team. They should have a few, a new one comes in the kit every year and they have been the same since 2000.
Radio attenas are funny things. I don’t pretend to understand them, but my expeince has led me to assume that if looks broke, it is broke. You can get replacement attenas, the broken one should screw out. The chances of buying a new one are pretty slim, but maybe you could find something that would work. Again, check with your team if the new power supply doesn’t fix things up. All the attenas should be the same from year to year, so perhaps you could borrow one.
Sounds very cool. Glad to hear things are coming along.
-Andy A.
Update!
Today we were able to get the radios working thanks to the original AC adaptor being put to use. Theyre communicating nicely, and we’ve got the throttle of the car under total remote control. Thank you for all the help on the radio issue! 
congratulations and good luck with your project, please keep us updated.