ESP32 Forum

Hi,

I'm currently trying to implement indoor positioning system using 4 ESP32 microcontrollers where one board is a 'master' and other three are 'slaves'. The slaves are configured as AP, so I can use 'HTTP_GET' request from 'master' to get the needed data from 'slave' nodes. So far so good.. But the problem rises when I try to get the position of a BLE beacons. Because I need to scan beacons to get their RSSI values to each ESP32 and also transfer this data then to 'master', I need to use both WiFi and Bluetooth libraries. The main problem WHY I cannot use this approach/architecture is that my ESP32's has not enough flash memory. The specification told that it'll have 4x more memory..

The following error is shown:
"Sketch uses 1661386 bytes (126%) of program storage space. Maximum is 1310720 bytes."

I also tried to include only needed header files, but it also didn't do much..

The question:
How can I transfer small data like 10bytes or so from each 'slave' to 'master' without adding HUGE libraries ?
I know that it can be done using bluetooth signals but I couldn't find understandable samples. I'm beginner at this.. :'(
This is for my bachelor theses, not much time left.. please help!

BR,
Ed

If you search this site you will find that using WIFI with Bluetooth is almost impossible due to the large compiled size of the two together.
I have overcome this only by using two ESp32'a one for the WIFI connection and one for the bluetooth with a standard hardwired serial in-between
There seems to be a lot of issues with ESP32 in combined usage WIFI and I2C is another one..

you may also use UART RX/TX between both ESPs, but not wired by cables but with 2 paired HC05 modules in between for WL transmission, using just the standard Serial communication though.

Hmm, connect external bluetooth modules to bypass integrated bluetooth modules. Sucks

The maximum size is limited by the partition layout of your flash. You can change that; some quick Googling turns up e.g. this.

We are successfully using WiFi and BLE on the same ESP32 device. But we did have to increase the flash partition size to 1.3 Meg.

Phil.

An example would be nice.