Remote control boats and cars from Android phone

Forums › Gadgets, robotics, home automation, electronics (including wearables) › Remote control boats and cars from Android phone

greg0

10 posts

Wannabe Geek

#290441 11-Nov-2021 20:08

I am looking for tech advice on RC cars and boats, What do i buy to make a simple system that can be paired and controlled from an Android phone.

Context. I am a technology teacher ( woodwork and metalwork ) wanting students to build cars or boats and control them Via Bluetooth from their phones.

Within a classroom or school swimming pool , so not big distances.

I don't want to use Arduino bits joined together. I would prefer ready to go receivers that connect to servo's. Basically multiple receivers paired to phones. would be best.

I would like to hear from anyone who has done this or similar.

Thanks

pih

649 posts

Ultimate Geek

Lifetime subscriber

#2811259 11-Nov-2021 21:03

For a ready-made solution, you could try Makeblock mBot or similar. For the boat all it would take is swapping out the motor gearboxes for a couple of motors with prop couplings and you pretty much have the boat bits complete.

To do an RC car it might need a bit more work or a different kit: the mBot uses a two-motor differential (in electronic terms an H-bridge) for steering (either motor can go forward or reverse independently), whereas you'd probably want a separate steering channel to power a steering servo, and a channel that just controls the speed going to the drive motor.

The mBot is pretty pricey, but it's off-the-shelf and available from the likes of PBTech. You could go cheaper with kits from AliExpress, but there will be a lot more fiddling involved, and there may not be an Android app that works over BT without a lot of fuss.

pih

649 posts

Ultimate Geek

Lifetime subscriber

#2811272 11-Nov-2021 21:45

If you leave out the requirements of Android and BT, there are off-the-shelf kits that will do what you need for the RC car, eg.

https://www.auselectronicsdirect.com.au/2.4ghz-digital-remote-control-transmitter-and-rece

https://www.aliexpress.com/item/32962794540.html?algo_pvid=8ed90fa6-efc3-45e6-a950-9d72ecaaef31&algo_exp_id=8ed90fa6-efc3-45e6-a950-9d72ecaaef31-1&pdp_ext_f=%7B%22sku_id%22%3A%2266569828132%22%7D

https://www.aliexpress.com/item/32961480496.html?algo_pvid=9c8723a8-1ffa-4938-b09e-deeaee16eb93&algo_exp_id=9c8723a8-1ffa-4938-b09e-deeaee16eb93-7&pdp_ext_f=%7B%22sku_id%22%3A%2266500350216%22%7D

There will be local suppliers as well, but I'm not really across that at the moment. You'd need a speed controller matched to your motors (brushed/brushless) to go with the first two kits above, the third one appears to have a basic brushed motor driver built in, but it will be limited to powering the small hobby motors.

greg0

10 posts

Wannabe Geek

#2811356 12-Nov-2021 07:10

Hi, Thanks for the reply, Android and Bluetooth are the main requirements, Leggo seem to be the only ones that have this sorted. I cant believe there are no other options

blackjack17

1705 posts

Uber Geek

#2811419 12-Nov-2021 08:18

would something like this work?

https://www.tinyosshop.com/index.php?route=product/product&product_id=666

Dual motor so steering by differentially powering the motors like a tractor or tank.

Can be usb powered so can powered by a powerbank.

Has a Bluetooth module and android app.

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greg0

10 posts

Wannabe Geek

#2811811 12-Nov-2021 15:48

Hi,

Thanks for the reply, That is looking more like it. Not sure if there is the ability to have multiple phones connected to boards. Bluetooth pairing for each board to a device is another thing i am looking into.

Thanks heaps for your help.

greg0

10 posts

Wannabe Geek

#2812087 13-Nov-2021 08:29

I also found this article.

https://findanyanswer.com/how-can-i-control-my-remote-control-car-with-my-phone

It looked very promising but didn't work with my RC receivers. Can anyone help?

Bung

6477 posts

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#2812102 13-Nov-2021 09:04

What are your receivers? Do you know they use Bluetooth?

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kiwiharry

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#2812126 13-Nov-2021 09:30

Bung: What are your receivers? Do you know they use Bluetooth?

From the other thread that was created looks like he got these receivers, but don't think they support Bluetooth technology
https://alexnld.com/product/austar-ax6s-2-4g-4ch-receiver-for-rc-car-boat-model-transmitter/

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richms

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#2812267 13-Nov-2021 12:25

Adafruit have done some tutorials on this and have an app to do the controlling over bluetooth le - https://learn.adafruit.com/bluefruit-le-connect/controller

Not sure what hardware will recieve it, probably there will be something to run on an ESP32 with a motor driver attached to recieve it.

Richard rich.ms

greg0

10 posts

Wannabe Geek

#2812286 13-Nov-2021 13:32

Hi, Thanks for the reply, I am trying not to use Arduino, it just gets too complicated for my students who are wood work or metal work based.

Both Bluetooth and Radio control use the same frequency and the app i linked to in previous post is made for this type of thing. Just need to figure out which receivers and bench test them with some servos. Could be that i need name brand receivers. When i search for Bluetooth devices i find them listed as their manufactures numbering. Unlike Bluetooth sound devices which show up as their name brand. EG UEMegaboom etc. I will keep trying.

pih

649 posts

Ultimate Geek

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#2812413 13-Nov-2021 23:06

greg0:
Both Bluetooth and Radio control use the same frequency ...

I just want to make sure you aren't under any illusions here: Even though Bluetooth and common RC systems both use the ~2.4GHz frequencies, they do not talk the same language. Bluetooth radios on phones can be used to talk to any Bluetooth device, but it can't be used to communicate with common 2.4GHz RC receivers, unless it explicitly says it's Bluetooth. Totally different tech.

2.4GHz RC systems are medium to long-range, often only one-way radios with low latency and several different proprietary and incompatible but fairly basic TX/RX protocols.

Bluetooth was designed with computers and peripherals in mind: it's a short-range, low power, bi-directional and generally slightly higher latency serial connection: so you need something that can talk over a serial port on each end. This is why so many solutions use Arduino or other microprocessors: because they communicate natively over serial.

richms

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#2812414 13-Nov-2021 23:51

pih:

I just want to make sure you aren't under any illusions here: Even though Bluetooth and common RC systems both use the ~2.4GHz frequencies, they do not talk the same language. Bluetooth radios on phones can be used to talk to any Bluetooth device, but it can't be used to communicate with common 2.4GHz RC receivers, unless it explicitly says it's Bluetooth. Totally different tech.

2.4GHz RC systems are medium to long-range, often only one-way radios with low latency and several different proprietary and incompatible but fairly basic TX/RX protocols.

Bluetooth was designed with computers and peripherals in mind: it's a short-range, low power, bi-directional and generally slightly higher latency serial connection: so you need something that can talk over a serial port on each end. This is why so many solutions use Arduino or other microprocessors: because they communicate natively over serial.

That is bluetooth classic. Bluetooth LE is basically a standardized version of the pretty primitive protocols used by numerous transceiver chips like those from nordic for cordless mice etc. Things for discovery of devices etc. There isn't even really pairing with it, just things connect together when they see each other.

The idea of getting a classroom of people putting devices into pairing mode and then connecting their smart device to the one that they need to is something I think would be quite funny to watch with them all connecting to each others ones.

Richard rich.ms