Hey,
this question concerns Wifi traffic maximum:
I coded a Art-Net-Node with an ESP8266 that runs FastLed to controll the Stripes over Wifi from any Art-Net Compatible Software/LightBoard.
Now the question is: where is the limit? Right now I’m planning to drive about 100 Art-Net-Node’s with 300 Pixels each. That means 30.000 Pixels, 90.000 DMX Channels, about 176 Universes.
I’m not an expert in Wifi Communication, but I know that the ESP8266 supports the 802.11n but without 5,8Ghz bands.
Can somebody tell me, if the project is realistic to get stable connections without drop-out’s?
Cheers,
Birk.
I guess the question is, what limit are you worried about? The ESP8266 has a fundamental speed limit due to the fact it’s a micro with limited bus speeds. I bet someone has established how fast a clean comm path and that chip will run. I’m sure google will tell you what the max is pretty quickly.
Your last question makes it more difficult. Without knowing more about the environment, it’s impossible to say whether you will get a stable connection. The data going over won’t impact the stability, but less stable means less bandwidth.
Basically, you can do the math on the total # of bytes passing, which I think is roughly in the several hundred K a second range, so it is unlikely that you will have bandwidth issues unless the link is really poor. I would guess the ESP8266 can support megabits in transfer speeds with a good link. But, YMMV. Testing here is the only thing that will tell you how it will work.
Thanks @Peter_Buelow . The ESP can do the job. I’m worried about the limits from the Wifi connection.
How does a Wifi-Hub deals with 100 devices connected?
Since it will be made for different locations, I can’t tell anything about the environment.
But yes, the ESP can support megabits and ok, I’ll try it.
as WebServer it should work fine (you have to connect to an existing WiFi). BUT as an access point you are limited to 4 connections
http://bbs.espressif.com/viewtopic.php?t=1155
Honestly, as long as the environment is relatively radio clean, as long as your AP can accept 100s of devices, then it should be OK bandwidth wise. But not many AP’s can support that many connections, so you’ll probably have to spread out the connections over a set of AP’s, similar to how offices do it. That’s a bigger question for better network guys though.
I’ve found the Zyxel range of access points will support up to 120 devices/connections (try the NWA3160-N). Most home routers/access points will ‘only’ support up to 30 devices, so you need to be looking at commercial stuff - I’ve also used the Ubiquity Networks access points, but they are more useful in a fixed environment as they are managed devices. Also directional WiFi aerials might help you - Maplins do one for a tenner in the UK.
Thanks @Kevin_Stevens . I decided now to realize the project with LAN-Connection in the first case, because after some tests I have the feeling, that it is pretty usual to have little lags in between. That could kill any light show.
So for the controller I will use teensy with LAN-Shield, but also with Wifi-Shield to test the Wifi usability. I’ll keep you apdated