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All things pertaining to wireless and RF links
By allibaster
#199532
I'm in the process of scoping out a new project that is in the realm of robotics. It involves one wireless controller that a person would use to turn and drive four wireless "pod" systems. Each of the four pods simply receives communication from the wireless controller and turns/drives a wheel. This will be used to move large objects of different dimensions, so the pods will be mounted in different distances from each other depending on the scenario.

Some requirements:
  • One wireless controller directs four wireless "pod" systems
  • Pod functions: forward, reverse, turn left, turn right
  • Pods can operate independently so the wireless controller can send specific commands to individual pods
  • Pods do not need to communicate with each other or back to the controller (open loop)
  • Max range is around 20 feet
  • 10-12 GPIO on the pods
I feel like this is very similar to a robotics chassis application, so there has to be some off-the-shelf development systems that would fit this application well. Any suggestions for microcontroller platform and wireless protocol?

FWIW, I have experience programming in C with Microchip PICs and Nordic bluetooth SOCs.
#199533
XBee would suit this application, but wifi modules are stupidly cheap these days. Even a Raspberry Pi Zero W would work (and they're only $10). You have an abundance of choices. You just need to pick the one you are most comfortable with and make it work for you.
#199534
darrellg wrote: Fri Jun 22, 2018 9:57 am XBee would suit this application, but wifi modules are stupidly cheap these days. Even a Raspberry Pi Zero W would work (and they're only $10). You have an abundance of choices. You just need to pick the one you are most comfortable with and make it work for you.
Thank you.

Yeah, I figured there would be a lot of options, but I'm trying to find the path of least resistance. I'm not familiar with any of those.

Any suggestions on the lowest amount of development effort with those options? Cost isn't critical, but I'd like to keep it under $50 per pod controller.
#199535
The simplest is probably XBee. Once a module is configured, you just treat it like a serial port. The controller can transmit commands and all the pods will receive. As long as you put some type of "address" in the command, the pods will know if it should use or ignore the command.

Here's a tutorial: https://learn.sparkfun.com/tutorials/ex ... s-and-xctu.
Here are the products that Sparkfun sells: https://www.sparkfun.com/categories/111.

Series 1 are the easiest to use, and they are available with 1mW or 60mW transmit power. They should work without configuration, but changing the PAN ID and/or channel will help avoid interference from anyone else using XBees (all of yours should be configured the same).
#199537
darrellg wrote: Fri Jun 22, 2018 10:40 am The simplest is probably XBee. Once a module is configured, you just treat it like a serial port. The controller can transmit commands and all the pods will receive. As long as you put some type of "address" in the command, the pods will know if it should use or ignore the command.

Here's a tutorial: https://learn.sparkfun.com/tutorials/ex ... s-and-xctu.
Here are the products that Sparkfun sells: https://www.sparkfun.com/categories/111.

Series 1 are the easiest to use, and they are available with 1mW or 60mW transmit power. They should work without configuration, but changing the PAN ID and/or channel will help avoid interference from anyone else using XBees (all of yours should be configured the same).
Thanks again. I'll dig into this over the weekend.