Wireless transfer of over 7 imu sensors

Hello,
I am working on a project in which 15 sensors are being used to record temperature, acceleration and gyroscopic data constantly, each is paired to its own esp32 module for power and connectivity. At this stage I want to be able to setup a wireless system of live data transfer from all 15 sensors to my computer where I will receive the data via serial and interpret it in Processing visually.

So far I have achieved live wireless transmission from up to three sensors using boiler plate BLE Arduino code examples, here I used a single esp32 as the master server which received data from 3 esp32-sensor pairs.

How might I overcome the issue of the maximum of 6-7 BLE devices connected to a receiver. The most intuitive solution to me is to create a hierarchy of Bluetooth server and client branches: e.g

/---- Submaster <----- 5 imus
Master Server <----<---- Submaster <----- 5 imus
---- Submaster <----- 5 imus

I fear this will introduce an impractical degree of lag in the data transfer and I am uncertain whether these “submasters” can behave simultaneously as master and slave or (server and client).

Please could you kindly advice me on the most suitable solution or avenue of research to this dilemma.

Please note that I have already searched this forum and others about this topic but each answer appears to be dependant on the specific to the application of the user hence my posting. Additionally people have mentioned the superiority of an NRF24 network for multi wireless connections, however my end goal is to have the sensors providing data directly to an android device with a custom built app to receive and process the data, hence my preference for BLE since I have read that NRF24 does not easily allow connection to android and Iphone devices. Additionally other methods such as having the master poll through multiple sensors appears to me be unfit for live data streaming.

Any advice regarding this would be much appreciated, apologies if I have not provided enough information I will endeavour to reply to any requests for more. Thank you very much.

Please could you kindly advice me on the most suitable solution or avenue of research to this dilemma.

WiFi?

iakel:
each is paired to its own esp32 module for power and connectivity

Is there any reason why the sensors are not all connected to a single ESP32?

...R

Why not just run MQTT Broker on your computer and have all the ESP32’s publish to the single computer? After that you can use Node-Red or write your own program to subscribe to the MQTT Broker and do the thing?

My weather station had a 2400mAh battery which ran on a battery for 4 nights and 4 days before I recharged it, the battery did not die. I send the ESP32 into a deep sleep for 5 minutes, wake up, do the publish, go back to sleep. The weather station is still in operation but with a 8Ah LiFepo4.

iakel:
So far I have achieved live wireless transmission from up to three sensors using boiler plate BLE Arduino code examples, here I used a single esp32 as the master server which received data from 3 esp32-sensor pairs.

How might I overcome the issue of the maximum of 6-7 BLE devices connected to a receiver. The most intuitive solution to me is to create a hierarchy of Bluetooth server and client branches: e.g

/---- Submaster <----- 5 imus
Master Server <----<---- Submaster <----- 5 imus
---- Submaster <----- 5 imus

I fear this will introduce an impractical degree of lag in the data transfer and I am uncertain whether these “submasters” can behave simultaneously as master and slave or (server and client).

Please could you kindly advice me on the most suitable solution or avenue of research to this dilemma.

I have tried various BLE examples for having a client grab sensor data from a server, and have yet to be successful. One example, for instance, has the entire BLE interaction programmed into setup() , and since it never runs again, I cannot change the value sent.

My intended use sounds very much like your 3 sensors to 1 master. In my case, I want to have four sensors send readings to one master. They will all be running on ESP32s with a WROOM processor. The master in turn will have one sensor, and all 5 sensors will be combined into one ‘packet’ to be sent over WiFi to be dealt with in a browser. We have the master working fine, reading a GY-521 with an MCU6050 Gyro/Accelerometer. This master contains a web page that is sent over WiFI.

So our main problem now is to add 4 more servers, each one responding with a Z-axis reading.

Have you published your 3-into-1 solution anywhere?

Oh, and not that I know anything about using ESP32 in a MESH configuration, but it sounds like that would be a good solution for speed.

I would be very interested