Using ESP32 WROOM modules outdoors in sunlight, temperature margin

[wonderfuliot]

Hi,

I have a street lighting project for which I plan to use ESP32 WROOM modules.
Since the street lights are going to be in sun (summers get pretty hot where these are going to be used), is it okay to use these modules at temperatures of strong direct sunlight, the modules max temp is 85 degrees as per datasheet?

Given that the electronics also will generate a bit heat, is there sufficient margin?

Thanks,
WI

[Franco]

Hello WI, you will have to take care of heat dissipation beyond the ESP32-WROOM-32D/U as I presume there will be more active and passive components on the board, including power supply (BTW, carefully select the electrolytic capacitors, which characteristics are affected by both high and low temperatures). If the system is off during daytime, the storage temperature of the ESP module is -40C/+150C, while the operating temperature range is -40C/+85C. If you are still concerned about temperature going above 85C during operation, you can also contact sales@espressif.com regarding the availability of the ESP32-WROOM-32D at 105C or PM me if you are based in Europe. Thank you for considering Espressif solutions for the Internet of Things. Enjoy!
Franco (from Espressif Sales)
PS: Have you looked at ESP-MESH? It's a good street lighting solution, allowing to extend the transmission range, with one node only connected to the AP and each other ones daisy-chained.

[wonderfuliot]

Thanks for the quick response.

I will do a test to measure ambient temperature in the field to assess the real situation regarding the temperature.

Regarding the ESP-Mesh, is there a way to increase the supported nodes to 1200? #define or something like that.
Is the code open source?

Thanks once again,
WI

[wonderfuliot]

How does one control the ESP-Mesh nodes from a street lighting controller based on Raspberry Pi?

[ESP_LBB]

Hi WI,

The ESP-MESH is designed and aimed to support over 1000 nodes.

All the nodes can be easily controlled via the server.

Here are some links that may be useful:

Introduction of ESP-MESH: https://github.com/espressif/esp-mdf

API Guide of ESP-MESH:https://docs.espressif.com/projects/esp ... _mesh.html

MDF: https://github.com/espressif/esp-mdf

Thanks.

[wonderfuliot]

Where do I see the #define for the max number of nodes in the network?
Thanks

[ESP_LBB]

Hi,

For ESP-MESH, we can define the max_connection and man_layer in the code.

max_connection is the number can be connected to a single node, up to 10 maximum. Usually we suggest to set it to 6.
max_layer is the maximum layer that a mesh network could be, up to 25 for now(we can increase this for some special application case). Usually we suggest to set it to 6.

So then the total node maximum for such a network with max_connection = 6 and max_layer = 6:
1 node (root) for the 1st layer;
6 node maximum for the 2nd layer;
36 node maximum for the 3rd layer;
...
This should be able to cover most general situation. And you can adjust it with the real situation.

Here some links may be useful to you:

Introduction of ESP-MESH: This doc will help you get the basic idea of how ESP-MESH works.
API guide of ESP-MESH: This doc will help you get familiar of the API of ESP-MESH if you decide to develop your own application based on ESP-MESH.
Demo code for ESP-MESH function: This is the demo code for two most important functions, network and internal communication, in case you want to test the performance.
GitHub for ESP-MDF: Add net config module, upgrade module etc and complete application examples.