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I'm fairly new to all things RPi so im still trying to get my bearings. I want to control a robot from a distance, about a Mile approx. I have build the robot and i have no problem controlling it through SSH, but I want to deploy it in a field without internet.

I'm thinking of building some sort of remote controller that would include sensors both analog and digital and send that data wireless to the Pi in the robot.

I've read a bit about LoRa and LoRaWan but Im not sure the bandwith is sufficient to transmit the controller's data and latency is definitely a factor to consider.

Would that be the only option?

Any guidance is greatly appreciated!

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    LoRa radios can cover that range but TX rates are very low deliberately to limit impact on the frequency use. Have a look at blog.dbrgn.ch/2017/6/23/lorawan-data-rates for the limits. I've not seen a suitable free solution BUT know that there are WiFi experiments for long distances search for Cantennas - be warned the 'Pringles' solution is better for 5GHz not 2.4Ghz. Professionally I used to run lan speed across roads and warehouses BUT the cost was £Ks (and licence regulated)... – Andyroo Apr 7 at 15:30
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    I see, that was very informative thank you very much. I guess I'm gonna have to make it stronger on machine learning and just a gps module to keep the robot making decisions on its own and not depending on manual control. Thanks again! – Bernardo Belmar Apr 7 at 20:23
  • What is the range? – Sohan Arafat Apr 9 at 10:14
  • Ok, just a question, as far as "No Internet", does that mean you are against the use of internet or that you just don't have a wifi network setup? If you aren't against the use of internet, and don't mind paying a monthly fee (probably), maybe a mobile hotspot on the robot could work for you. That would essentially make the range of the robot from the operator infinite (as long as you have cell signal). – Patrick Mcvay Apr 9 at 14:32
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You can use Ubiquiti AirMAX products to easily get a connection across 1 mile, if you have line-of-sight.

Even the cheap Nanostation units would do it. I've used these on multiple setups with good success.

Then, you could install wireless repeaters in the middle of the field, to give you all-around coverage.

Note that you'll need reliable power in the field.

If you can run a cable, then you have more options. Fiber is the fastest but most expensive. You can also get over a mile from an ethernet-to-coax or ethernet-to-twisted-pair converter (see StarTech for options) for very little cost.

However, if I misunderstood, and you want to control the robot anywhere within a 1 mile radius of your location, then you'd need something totally different. I understood the question to imply that the robot is fixed in one place (or a small area) approximately 1 mile away from you. Please correct me if I'm wrong.

Good luck.

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  • Thank you for replying. I meant to say the operator would be stationary and the robot would be placed anywhere in a mile radius from the operator. Seems like I'll have to just get some LoRa/wans and try them out and figure out if its enough for me to use as controller. – Bernardo Belmar Apr 8 at 20:51
  • Will there be obstructions between operator and robot? i.e. trees, hills, etc? – Ryan Griggs Apr 9 at 0:36
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I think the issue is that you are asking for a mile or more of range and that seriously limits the options here. You will need a radio service that has that sort of capability. Assuming you're looking at using this unlicensed, that rules out many options open to licensed business users or licensed radio amateurs which could easily reach a mile.

FRS or GMRS are unlicensed services and can be used to transmit data and the equipment is relatively inexpensive. You'd need some sort of modem (modulator/demodulator) on each end and some sort of protocol but much of this sort of equipment is readily available.

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  • I see.. that seems to escalate the complexity of the setup but seems like at that range would be the only option. Can you think of any other option at a shorter range? maybe i can just adjust the operator's distance if that would make any difference in viability thank you for your time and help – Bernardo Belmar Apr 7 at 20:24
  • You can use 433 Tx/Rx to cover shorter range. All depends on the size of your antennas and the noise on the frequency that you choose. But no control over standard SSH you have to bring up a sort of service to manage a sort of protocol and trigger the action you want on command received. – MadPapo Apr 7 at 22:38
  • I've been looking into receiving analog input from a radio controller and convert them into something a Pi can understand. I saw something called "Universal Plus Hat RC" that seems to do the trick. Apparently the hat is discontinued but it would, at least in part, get the job done. Then it would be a matter of antenas and signal strength. I could then divide the signal into analogs for control and LoRa for sensor data. I'm surprised at how difficult it has been at least for me to find info in the subject.. i would have imagined someone would have done this before. Thank you for replying! – Bernardo Belmar Apr 8 at 20:56
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If you ar trying to work within a mile then you need an NRF module. What you need is to porgram another microcontroller and then make a transmitter. It would be great if you use some sort of amplifier to boost the signal.

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  • I still cant figure out if I'd absolutely need to use an arduino(which im absolutely ignorant about) with it or I could just use it with the RPi. I see people on the FPV community can transmit video, command and telemetry at around a mile radius ( moving the antenna toward the receiver) so I'm trying to figure out how to do something similar with the RPi. They can control their aircraft, get video feed and receive telemetry over those distances... I should be able to do that with the RPi too no? Any recommended resources on making a transmitter? Thank you very much for replying – Bernardo Belmar Apr 9 at 17:02

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