Better / Best Remote Control Options

Help & Support Robot Parts
1

Hi;

Sanity check and advice please.
We are entering a Robtics Challenge for schools which consists of a number of autonomous and remote controlled challenges. For remote control we are currently using a Pi Hut 2.4Ghz Wireless Game Controller:
thepihut.com/products/raspberry … controller
We have a couple of issues with this method:
(a). Every so often, normally at crucial moments’ the connection seems to get lost and either the Robot crashes or stops and cannot be moved, the controller flashes whilst it is trying to get a new connection and the all of a sudden we have control again.
(b). In the Roboteers hints section it says “Controlling your robot over WiFi can only lead to pain” and also suggests “Analog power control is best for controlling your robot in remote control mode, allowing for fine control of your robot. An RC transmitter or game controller are best for this”.
So I am guessing, to avoid disappointment on the day, we probably need to switch to full blown RC Transmitter Control (27Mhz). I have a cheap 2 Channel Transmitter that my son bought on eBay and I have a 2 Channel Receiver somewhere (they can be picked up cheap anyway. I just need a matching set or sets of crystals.
Is my thinking correct and any advice on what colour crystals to get?
We then need to find out how to control the Pi using the signals from the RC Receiver?? So any pointers on that would also be appreciated.

Many thanks

2

Hi,

Here’s a few points:

  1. When doing wireless communication, you typically expect communication errors and have your communication protocol handle those. It is possible that the controller you are using does this by simply dropping the connection and waiting for it to restart/reconnect (lazy way :stuck_out_tongue: ). If you had any way of changing how errors are handled on the transmitter and receiver side this may be easier, but in this case it is probably not modifiable.

  2. Going for a RC transmitter / receiver is certainly a valid idea. That being said, having only 2 channels may be a bit limiting, unless you only want to automate moving (in 2D).

  3. As for getting your own crystals to match the transmitter and make your own receiver, please note this is certainly not a trivial thing to do and will require some trial and error to achieve. Here is an example of one here. Please note this is a very basic, one channel device with no error handling or other issues from external interference. If you go and browse the website project, you’ll notice the project goes into more details as it grows into a more complex transmitter / receiver pair.
    We strongly recommend that you instead buy a “ready-to-go” transmitter / receiver pair, such as those found here / here. This will be much simpler to work with and also much more reliable for when you are at the competition.

  4. Using the RPi to read RC pulses is do-able, but may not be very simple, depending on what else you have running (since the RPi typically runs Linux or some other full OS, not a real-time OS). You can find plenty of examples online of how people have dealt with those challenges, such as here and here.

Lots of reading and trial & error ahead of you! Good luck with your project!

Sincerely,