Many ESP32 modules on single wifi access point?

[amarotica]

Hi All, long time reader, short time member here.

I am wondering if anyone has any experience (or information) on how upwards of 50 ESP32 modules would perform while being connected to a single wifi access point. The access point would be a dedicated commercial AP used only for these devices, but I am concerned that too many of the same devices, on the same default settings would cause issues. Would I need to change default channels or anything like that? The devices would intermittently be sending data via MQTT to a server for processing, although the data is only one or two small values, and sent anywhere from 10 to 30 minutes apart per device.

This question is because I am thinking about developing an IoT related system for a local business and although I've used the ESP32 modules for quite some time now, I haven't used them in such a large deployment. I use PlatformIO with ESP32 Arduino currently.

Thanks in advance!
Taylor

[bobtidey]

I don't think it is specifically to do with esp32, rather a question of the size of the packets and the rate at which they are being sent. If the interval between each mqtt packet is a decent amount then there should not be a problem in supporting a large number of devices.

I have about 35 esp8266 sensor devices reporting back to a database through a normal router AP without any difficulty and that is mixed in with plenty of other wifi network activity like phones etc.

One annoying issue I did have with a router initially was a limited capacity to allow setting static dhcp ip addresses (e.g. max 20). I prefer to set static dhcp so I know how to easily back access devices for configuration or update. I now run a router with Tomato flashed router firmware which does not have this type of limitation.

[lbernstone]

It will be dependent on the capability of the router. There should be no issue from the esp side with 50 independent nodes.
You could also use wifi mesh https://docs.espressif.com/projects/esp ... /mesh.html, which should work with minor tweaking up to 100 nodes, and the mdf claims to support over 1000 nodes https://github.com/espressif/esp-mdf

[amarotica]

Thank you bobtidey and Iberstone. Glad to hear that at least someone is doing it successfully. The MQTT messages will be published roughly every 20 minutes on each device, so that evens out to about 1 or 2 messages per minute over the wifi connection. I was primarily concerned with all the nodes using the same wifi channel but I don't know much about wifi to be sure. I'll go ahead with it and try it out, and look into esp-mdf if I see any issues.

Thanks!