wireless model rocket controllers

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I have a friend who has done that, he's an engineer for a high tech company. We both fly S8 rocket gliders and its so much better to control the launch yourself from your transmitter. He uses a Futaba and I use a Frsky both very good, solid systems. I plan to do similar with one channel to test for continuity, one channel to arm a receiver controlled switch and one to fire but only if the previous channels are good and if the transmitter flight mode is correct.


Richard

Question: How is this implemented? Single receiver in glider with disconnects to the pad or dual (Synced?) receivers?
 
Just out of curiosity why does everyone jump to 433mhz when they hear wireless? I never see designs with 2.4ghz. Is there a reason behind this?
 
Question: How is this implemented? Single receiver in glider with disconnects to the pad or dual (Synced?) receivers?

My radio and many others have a bay that allows the use of a second transmitter module operated simultaneously by the transmitter. Thats how Frsky can get 32 channels, 16 on the main transmitter and 16 on the secondary. The rocket glider is bound to the main while a secondary receiver is bound to the launch controller. This radio has a model match or model memory feature which does not allow any other receivers to be affected because each has a specific ID. I will in the future research whether a second receiver could be bound simply by changing its ID to the same as the first receiver so the second module might be eliminated. The glider would be on the lower channels and the launch controller on the upper ones.


Richard
 
Oh and yes if weight is not an issue and the battery in the glider/rocket is strong enough everything could be contained in the vehicle itself.


Richard
 
Just out of curiosity why does everyone jump to 433mhz when they hear wireless? I never see designs with 2.4ghz. Is there a reason behind this?

Propagation and range though technically one is supposed to have a Ham Tech license to operate at certain power levels in the 70cm band/433Mhz. Of note, I see my wireless outdoor thermometer is 433Mhz and they "aren't" restricted to Ham operators!
I believe they are very low powered and likely exempt or they're sold illegally but I doubt that. I don't think a large company like Taylor is going to flirt with the law.
A LP Beeline GPS on 70cm is just 16mW and performs very well on the Ham band. Was the only game in town years ago and was the reason I got into Ham Radio. A GPS tracking system back then cost as much as the purpose-built Walston and Falcon tracking
RDF devices. If one was going to spend that kind of money I figured I'd be happier with the accuracy of GPS tracking as opposed to the "bearing only" RDF.

Now look where we're at with tracking.

Honestly, If you're going to do wireless launching, do it for yourself. Use an encoded signal so it's less likely to cause a misfire and try not to interfere with another radio service. All of these are achievable especially since we generally fly in wide open areas.
I just wouldn't go into business doing it without careful consideration and resources of investment like already discussed in the other posts.

The Rocket Rev, Brad Wilson at Wilson F/X: https://www.wilsonfx.com/ Has a worry free turnkey system that can include wireless and costs accordingly. Many clubs post nothing but kudos. Kurt
 
If I may add my 2 bits....

A Wilson F/X system is a great example of how to do it right. Years of testing and refining the product line, and paying attention to every detail within it.

As to the Wilson F/X wireless option, I don't know all the specifics but, I have read much of Rocket Rev's Wilson F/X thread on these forums. Therein he has stated he uses Digi XBee modules (TX & RX) operating at 900 Mhz. The nice thing about 900 megs is that it is a License free band and offers extremely long range compared to 2.4Ghz at the same output level. These are the reasons I choose to use the Digi XBee Pro 900HP modules for my upcoming flight electronics project. Admittedly I'm still in the very early stages of design but the xBee system simplifies/streamlines a huge portion of the design process.
 
I was just cursious. I understand the range but it seems a bit overkill unless you have a need for it. Our club's system uses 2.4Ghz which has been tested to over 1000ft (no need to go further) which is enough for an N or complex M and was a tiny fraction of the cost of 433mhz and 915mhz systems. I wouldn't want this range in a rocket for tracker but works great in for launching.
 
...

The FCC regulations and process for commercial testing and certification of a device is documented online. It has nothing to do with an FCC amateur operator's license. The first thing to understand is that a HAM license is issued to operate a transmitter within limited bands for non-commercial use. FCC type-testing, certification, and issuance of an FCC ID, is required for a company to test, market, and sell a commercial device. Depending on the type of device and the band&power it operates within, the owner/operator of the device may or may not need a license. It can be license-free (Wifi, cellphone, garage door opener, for example), or an amateur license (ham band HT, for example), or a commercial operators license (TV/radio station, company's mobile fleet radios, etc).

Understand also the FCC typically doesn't police the airwaves. Any action from the FCC usually begins with a complaint from the public or a commercial operator or the military. They gather information, and the legal department decides if it's worth a warning, a fine, or a docket to be turned over to a US attorney's office. I've been on both sides of this process. ;-)

There's a fine line in the regulations when it comes to reselling a transmitting device as part of an integrated system. If the original device is a module intended for multiple applications, you only need to show that it still works within the limitation for that band once it's integrated into your product. But, if it's a transmitting device intended for (and certification tested, type-tested for) a specific application, you can't just integrate it into your product for a new application. The FCC will usually require new type-testing ($5K to $20K, performed by an independent testing company). Many products are in violation, but again the FCC is not typically a policing organization.

An individual or small company may decide to "wing it". All is well until there is a complaint from interference, or worse, someone is injured using the product. When the lawyers find you were in violation of Federal regulations, they will use it as an example of incompetence. It might not have anything to do with why the incident occurred, but you will lose everything you own trying to prove otherwise.
...

This discussion has me wondering if there is any commercially available wireless launch control system that has gone through the type of consumer safety testing John describes. ????
 
You probably don't want to open up that can of worms.

The FCC requires ID labeling on the outside of the device and a compliance statement in the manual. This is required even if you are integrating a module that was FCC tested and registered by another manufacturer.

At least a couple of modifications require retesting and registration by the (integrating) manufacturer: different antenna, or a software-defined radio with changes in the software. Basically, follow the guidelines from the module manufactured that are required to stay within the hardware and software configuration it was certified under.

There's a recent FCC decision to allow self-testing of compliance for certain types of devices (non-transmitting, unintentional radiators, and host system with a pre-certified module). No need to pay an approved FCC testing lab. Still, the manufacturer has to know what the required test are, know how to write up the results of the tests, and send it in to the FCC. If you don't have the background or the equipment, you still have to pay a testing lab to do it for you.
 
You probably don't want to open up that can of worms....

I definitely don't! I have no expertise with electronics and my only excuse is feeling cocky after a little vacation where I slept at a Holiday Inn. :)
Carry on !
 
You probably don't want to open up that can of worms....
A big part of my job is designing stuff (spectrometers and accessories) for sale internationally and being involved with the compliance testing. Trust me, you definitely don't want to open that can of worms.
 
Propagation and range though technically one is supposed to have a Ham Tech license to operate at certain power levels in the 70cm band/433Mhz. Of note, I see my wireless outdoor thermometer is 433Mhz and they "aren't" restricted to Ham operators!
I believe they are very low powered and likely exempt or they're sold illegally but I doubt that. I don't think a large company like Taylor is going to flirt with the law.
A LP Beeline GPS on 70cm is just 16mW and performs very well on the Ham band. Was the only game in town years ago and was the reason I got into Ham Radio. A GPS tracking system back then cost as much as the purpose-built Walston and Falcon tracking
RDF devices. If one was going to spend that kind of money I figured I'd be happier with the accuracy of GPS tracking as opposed to the "bearing only" RDF.

Now look where we're at with tracking.

Honestly, If you're going to do wireless launching, do it for yourself. Use an encoded signal so it's less likely to cause a misfire and try not to interfere with another radio service. All of these are achievable especially since we generally fly in wide open areas.
I just wouldn't go into business doing it without careful consideration and resources of investment like already discussed in the other posts.

The Rocket Rev, Brad Wilson at Wilson F/X: https://www.wilsonfx.com/ Has a worry free turnkey system that can include wireless and costs accordingly. Many clubs post nothing but kudos. Kurt

K, thanks, Kurt and others.
 

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