I am planning a indoor/outdoor home Christmas light display with addressable and RGB leds. Indoor because some of the decorations will be hanging in windows. I figured I will need 6 MCU controllers that are physically separated by 30ft at most. There may be 19 led strips total running from the 6 controllers (MCUs).
What I'd like to do is to have a start flag triggered at one MCU, which is then broadcast to all controller stations, which will start a show timed with music. I figure if millis() is accurate enough on all controllers then the show could work well, as long as the command is processed about the same time on all MCUS.
I have several years experience with Arduino but my wireless experience has so far been with Bluetooth 1 to 1 connections with HC-05s. I have recently picked up some Wifi enabled boards including an ESP32 and look forward to using them especially with their greater range capabilities.
My questions are:
Can the command broadcast be done easily over wifi connections? I think I would start with broadcasting simple short serial commands.
What is your opinion of the project approach and feasibility ?
Broadcast over WiFi is not easy. WiFi is not really meant for that.
For your application, it sounds like the most basic type of 433MHz transmitters might be ideal. They naturally broadcast to any receivers listening on the same frequency, and the longer wavelength penetrates walls better. You only need to send very simple message like "run sequence #7".
Do you think the 433Mhz would this work outdoors as well within 30ft? Have you ever used it? If so how does it compare to nRF24L which I've read can have a very long range?
I am very interested in WIFI due to OTA updating and possibility of interacting via webpage. I would use a wifi extender to get the signal outside. It would be great to get it to work.
Higher frequency = shorter wavelength = less penetrating. Laws of physics.
Nrf24 uses 2.4GHz band. That's 10 times the frequency and so one tenth the penetration of 433MHz. If you need high speed data, then fair enough. If you don't need high speed data, why make life difficult?
Sorry, that was unfair. The advantage of 2.4GHz is that it is WiFi frequency. So if you can live with that, you can connect to the net. And that's a huge advantage.
I was thinking I would have individual sketches programmed on each MCU that control their own leds, but the programs would all be initiated at the same time and so that's the only necessary control signal.
I know there are PC based programs and DMX etc but I'm trying to do this with low cost and I thought with neopixel/FastLed strip programming experience I could do a good job with an Arduino based system. BTW I have found 5m WS2812B strips (5V, waterproof, 1.25" spacing) for $16 via ebay.
It looks like there are several mesh libraries and these sound promising: ESP8266WiFiMesh, painlessMesh, APC220 wireless mesh. I think I really want to stick to WIFI because OTA. Maybe use a 433 separate module to do broadcast commands and WIFI for updating?
The diy xmas light page looks good an I'm searching for others as well. Thanks.
I think that wireless control over wifi using esp8266 is very very easy. Way easier than 433mhz radios, which offer a flaky connection and require a perfectly designed antenna to work.
My advice is don't waste your time with rf radio.
The esp8266 supports mesh networks so you don't even need a router. There are tons of examples online, search "fastled websever" on google and you can get a working project set up in about ten minutes. Controlled by your phone.