Use without WiFi

Hi all,

I’ve just discovered the Pixelblaze and am very excited by what I see!

One thing I can’t figure out though, is whether the system works well without WiFi.

I want to create an LED controller to take to camping festivals, and want to still be able to control via bluetooth (or even better, be able to wire up some buttons to choose between favourite modes).

So, once I have setup the system on my home WiFi, can I plug and play while out bush?

Thanks!

Hey @DarbyB!

Pixelblaze doesn’t support Bluetooth, but I never miss it, and I’ve used a bunch of them in places where there’s no internet.

At home I use it in “Client Mode”, where the Pixelblaze is connected to my home WiFi. This way I can program it from my computer, but it’s also able to get firmware upgrades from the internet, and my computer can reach both the internet and the Pixelblaze at the same time.

When I take it out to a place where there’s no internet (and generally, no WiFi router), I like to configure it for “AP Mode”, where the Pixelblaze broadcasts its own network that my phone or computer can join. That’s how I remote control it to change patterns or edit them.

If you’re thinking about using a physical button to change modes, have a look at the posts here that discuss soldering an external button to the board (which just acts like an extension cord to the tiny onboard button). You can select some of the patterns you like to be in the playlist. If you’ve set it to playlist mode, pressing the button will advance the patterns between those on the playlist. If you’ve configured this before you head out, there’s no need to even connect to the Pixelblaze over WiFi while out there. The button will just keep advancing the playlist, even if you disconnect power.

A nice feature is that if you press and hold the button for 5 seconds, it will reset the Pixelblaze board to be in setup mode, which lets you select AP mode or Client mode. Out bush, you can use this with a phone to reconfigure it to AP mode and fix anything from a laptop or phone (for example, if you forgot to enable the playlist).

Let me know if you have any other questions!

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Hey thanks for the tips! That sounds like it will work well for me, especially knowing that it has a playlist mode of sorts.

Do you know whether I can add a rotary dial or up/down buttons to control brightness?

I’d probably default to using the main brightness slider (top right corner) from my phone, if you can stand to have a phone on you in this environment. I just did it this morning to adjust my kids costume for daylight viewing!

You can also wire up a potentiometer to the ADC input and use that to control brightness, but you’d need to add the right code to every pattern you want to control this way, which is why I suggest using the global brightness slider from a phone (it’s a lot less work).

I added a potentiometer to control brightness for a very bright LED coat where I wanted super quick access and could turn it down when someone was talking with me. I hit a sensor board in the sleeve and added a potentiometer there. Then it was a few lines of code per pattern. Just gotta find where the pattern passes in V to hsv() and multiply by the reading. e.g.

hsv(h, s, v)

For the sensor board becomes:

hsv(h, s, v * analogInputs[0])

For on-board analog, you’d want to read brightness once per frame to avoid doing an ADC conversion for every pixel, and store that in a variable:

var myBrightness
pinMode(33,ANALOG)
export function beforeRender(delta) {
  myBrightness = analogRead(33)
  //existing beforeRender pattern code....
}

Then likewise modify calls to hsv with the myBrightness variable:

hsv(h, s, v * myBrightness)
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