And back to the problem of legality. Such a use is strictly prohibited by Part 95, unfortunately.

Yes and reading through all of that was an awakening experience. My next best would be WiFi depending on distance or the walkie talkie route. No clue what frequencies are open for what the thread starter wants to do.

Ron

 

Yes and reading through all of that was an awakening experience. My next best would be WiFi depending on distance or the walkie talkie route. No clue what frequencies are open for what the thread starter wants to do.

Ron

Aside form 2.4GHz and possibly 27MHz, the only service/band I can find that explicitly permits this exact use is the RCRS (Remote Control Radio Service) in the 74-76MHz band.

I don't know if 27MHz is a good idea for a safety mechanism given the mess on the 10m band. The RCRS band is good but the gear seems pricey.

 

I don't know if 27MHz is a good idea for a safety mechanism given the mess on the 10m band. The RCRS band is good but the gear seems pricey.

Have to agree with that. I don't know that I would trust anything to 27 MHz (11 Meter) band. While I have not listened to CB in decades it was always a mess as I recall. There are 900 MHz walkie talkies but that stuff is not exactly cheap. I guess we wait and see what happens.

Ron

 

So actually I do like that idea of using a $20 RC toy and just kind of ripping it apart to repurpose it. That seems legally quite safe, as it's essentially doing the same exact thing. Yes, technically I'm repurposing equipment not certified for such purpose, but I'm not worried about getting busted for that.

The other option could be to get a Bluetooth or WiFi module for my Arduino-compatible circuit board, and either connect to my phone or make a dedicated module to go with the kart similar to my original walkie-talkie idea. This would still be a pretty cheap option, as ESP32 boards are really cheap, and so are the independent Bluetooth and/or WiFi modules. Further, since the Bluetooth/WiFi modules are not directly controlling the device, they are only TX/RX signal, and that signal is being sent to a separate controller, I can easily avoid any issues about "using the wrong frequency to control devices."

In fact, this goes back to the FRS. Since I can send digital signals over FRS under the US codes we were talking about, why can't I use the walkie-talkies? I will be using them strictly for sending digital ON and OFF signals, which are allowed, are they not?

EDIT: To clarify again, the TX would just send ON or OFF essentially, and the RX would forward the signal to my circuit board. The circuit board would then interpret the signal and act accordingly. This seems like it should be totally legal, almost a sort of "loophole."

 

Have to agree with that. I don't know that I would trust anything to 27 MHz (11 Meter) band. While I have not listened to CB in decades it was always a mess as I recall. There are 900 MHz walkie talkies but that stuff is not exactly cheap. I guess we wait and see what happens.

Ron

What's 1m between friends?

 

So actually I do like that idea of using a $20 RC toy and just kind of ripping it apart to repurpose it. That seems legally quite safe, as it's essentially doing the same exact thing. Yes, technically I'm repurposing equipment not certified for such purpose, but I'm not worried about getting busted for that.

The other option could be to get a Bluetooth or WiFi module for my Arduino-compatible circuit board, and either connect to my phone or make a dedicated module to go with the kart similar to my original walkie-talkie idea. This would still be a pretty cheap option, as ESP32 boards are really cheap, and so are the independent Bluetooth and/or WiFi modules. Further, since the Bluetooth/WiFi modules are not directly controlling the device, they are only TX/RX signal, and that signal is being sent to a separate controller, I can easily avoid any issues about "using the wrong frequency to control devices."

In fact, this goes back to the FRS. Since I can send digital signals over FRS under the US codes we were talking about, why can't I use the walkie-talkies? I will be using them strictly for sending digital ON and OFF signals, which are allowed, are they not?

EDIT: To clarify again, the TX would just send ON or OFF essentially, and the RX would forward the signal to my circuit board. The circuit board would then interpret the signal and act accordingly. This seems like it should be totally legal, almost a sort of "loophole."

Did you see the ~$50, much more reliable, 2.4GHz RC car controller I linked to earlier in the thread?

 

In fact, this goes back to the FRS. Since I can send digital signals over FRS under the US codes we were talking about, why can't I use the walkie-talkies? I will be using them strictly for sending digital ON and OFF signals, which are allowed, are they not?

EDIT: To clarify again, the TX would just send ON or OFF essentially, and the RX would forward the signal to my circuit board. The circuit board would then interpret the signal and act accordingly. This seems like it should be totally legal, almost a sort of "loophole."

You can't use FRS to control anything, no matter the duty cycle.

 

Did you see the ~$50, much more reliable, 2.4GHz RC car controller I linked to earlier in the thread?

How much more reliable than a decent quality FRS walkie-talkie?

 

How much more reliable than a decent quality FRS walkie-talkie?

See above. FRS can't used for remote control. It doesn't matter how long or what you transmit.

 

Also, if you are willing to use an MCU, then you can look at the discussion concerning intermittent transmission with the 433 module. Depending on the transmit time for one signal, you could do a watchdog instead of a deadman and stay within the law.

But, a watchdog has some fixed latency, so you have to be OK with that.

 

One more thing, the RC controller has multiple channels, if you were inclined you could wire up braking and even steering which is outside the scope but sounds fun

 

You can't use FRS to control anything, no matter the duty cycle.

It's not controlling anything, it's sending a digital signal. Now the question is, in terms of law, what defines "control of a device?" I don't have an answer presently. Does it have to control it directly? What about indirectly, such as containing a relay? Since the signal is only sent to a controller device, and not actually containing the equipment, not even indirectly, I would believe this to be a sufficient loophole. But I don't know for certain.

 

It's not controlling anything, it's sending a digital signal. Now the question is, in terms of law, what defines "control of a device?" I don't have an answer presently. Does it have to control it directly? What about indirectly, such as containing a relay? Since the signal is only sent to a controller device, and not actually containing the equipment, not even indirectly, I would believe this to be a sufficient loophole. But I don't know for certain.

It's the opposite. The law explicitly permits data for communication between people while prohibiting other transmissions. You are not communicating with a person,

But, given your reason for this, which is safety, do you really want to risk positive control on a shared band with a lot of traffic on it and no supervisory control?

Obviously, it's up to you how you do this but I think I'd fork out the 50 bucks for something designed for purpose.

 

One more thing, the RC controller has multiple channels, if you were inclined you could wire up braking and even steering which is outside the scope but sounds fun

My go kart has electronic breaking which could be handled by the MCU device anyway. Remote steering would require adding some powerful servos, an expensive endeavor I have no real interest in at this moment. Sounds fun, having a 200lb RC car, but expensive and risky.

 

My go kart has electronic breaking which could be handled by the MCU device anyway. Remote steering would require adding some powerful servos, an expensive endeavor I have no real interest in at this moment. Sounds fun, having a 200lb RC car, but expensive and risky.

Well, with the RC controller you could have acceleration and brakes anyway. Possibly an adjustable on the fly speed limit?

 

It's the opposite. The law explicitly permits data for communication between people while prohibiting other transmissions. You are not communicating with a person,

But, given your reason for this, which is safety, do you really want to risk positive control on a shared band with a lot of traffic on it and no supervisory control?

Obviously, it's up to you how you do this but I think I'd fork out the 50 bucks for something designed for purpose.

Oh ok, I missed that the data must be between people.

I think a Bluetooth module or two would be a cheaper and easier option than the $50 one you suggested, but it's a good suggestion, thank you. If I get cheap Bluetooth modules designed for my MCU they will be very easy to integrate instead of trying to figure out how to integrate the other device.

 

Oh ok, I missed that the data must be between people.

I think a Bluetooth module or two would be a cheaper and easier option than the $50 one you suggested, but it's a good suggestion, thank you. If I get cheap Bluetooth modules designed for my MCU they will be very easy to integrate instead of trying to figure out how to integrate the other device.

Bluetooth is OK, but WiFi might be better. In any case, please do report back on things. I ordered those modules to test timing since we have the idea that they could be compliant in a watchdog role. I will report the timing in this thread when I get them.

 

EDIT: To clarify again, the TX would just send ON or OFF essentially, and the RX would forward the signal to my circuit board. The circuit board would then interpret the signal and act accordingly. This seems like it should be totally legal, almost a sort of "loophole."

This is different from the original requirements. Initially, you wanted the On signal to be continuous, so if the kart lost contact it would stop.

Now you seem to saying you want an On and an Off signal, not continuous. This case if the kart drives out of range, you will not have control of it to stop.

Please clarify once more.

 

This is different from the original requirements. Initially, you wanted the On signal to be continuous, so if the kart lost contact it would stop.

Now you seem to saying you want an On and an Off signal, not continuous. This case if the kart drives out of range, you will not have control of it to stop.

Please clarify once more.

OFF would be, in this case, equivalent to losing signal. The RX device looks for an ON signal continuously, and if it doesn't find it, then it will disable itself. Strictly speaking, they're will only be ON or [no signal], not an OFF command.

 

Just ordered these guys from Amazon, seems promising: https://www.amazon.com/dp/B00O9O868...abc_WMWCW2YJDS2PYZCQ53R3?_encoding=UTF8&psc=1