Array of Wireless Wixels

I’m new to this forum and have in mind a project where I would need an array of wireless Wixels to communicate to a Win7 laptop (via a Wixel “router”).
My questions are:

  1. If there are 256 wireless channels and the Wixels have to be separated by 2 channels then the effective array is 128, correct?
  2. Does each channel have a MAC address? If not, how is each channel identified by the router?
  3. What should I use as a router to the laptop if not a Wixel?

Thank you.

Hello and welcome to the forum.

Yes, it would be hard to use more than 128 different channels.

Wixels do not have a MAC address and do not perform any of usual protocols used in networking. The Wixels do have a unique, random, 32-bit serial number and you could use this to identify nodes in the system. For an example of that, you can look at the wireless_adc_rx and wireless_adc_tx apps in the Wixel SDK. Another way to identify the Wixels would be to just have each Wixel in the array be on a different channel, and have the “router” Wixel switch channels depending on which Wixel it wants to talk to. Then the Wixels would be identified by the channel they are operating on.

I would recommend using a Wixel as a router connected to the laptop.

The Multi-Agent Grid Navigation project from Tabletop Robotics might be a useful thing to look at.

–David

Thanks David for you quick response. :slight_smile:
The Multi-Agent Grid Nav project looks just the thing to build the basis of my project!
The limitation on the number of rf channels available…will this increase with planned future releases of the Wixel?

Probably not, but you could probably get up to 256 channels if you decrease the radio data rate. This would require you to really dig into the details of how the Wixel’s radio works and make all the necessary changes to the radio register values and the timing parameters in the radio libraries. Before going through all that trouble you should do some tests first to see if it is actually a problem to have Wixels on consecutive channels, without changing the data rate. When we did those tests, we found there was some interference between Wixels on adjacent channels, but I don’t believe it resulted in invalid data getting received; it just caused some packet loss and that might be acceptable to you.

–David

Thanks for your advice.
I’ll check those things out…but it seems the proof is in the pudding…

Hi

Just wondering if I can directly connect the output of my GP2Y0D8010Z0F Sharp Sensor(s) to pin P1_3 of my Wixel(s) or do I need to introduce peripheral components between the two to limit current draw?

Thank you.

Hello.

No, you do not need a device to limit current when reading the output of that Sharp distance sensor with the Wixel. However, that device outputs a high or a low signal, and how high the high value is depends on what you supply to VIN. The Wixel’s GPIO pins are not 5V tolerant, so to safely read a logical high, you should not supply more than 3.3V to VIN on the distance sensor.

-Jon

Jon

Thanks for that info.