Best solutions for connecting several slaves to one master (Bluetooth, ESP)

Welcome,

i have been thinking for a while now how best to solve the connection of 2 and more devices to one receiver/transmitter.
How best to solve the connection when data has to be transmitted both ways ? Bluetooth modules 4.0 and above already have the possibility of networking, but usually after modifying the code of the controlling microcontroller. Are there better solutions than the ESP modules we all know ? Particularly the low power consumption, with a relatively low frequency and volume of data frames.

Regards,
Piotr

Bluetooth modules are a good option. There are also some that are controlled from an external microcontroller if you don't care about writing an application directly to the BLE chip. Writing an app for the chip itself might not be that difficult either. There are plenty of examples. I've used Nordic and Cypress chips and got off to a pretty nice start. Especially with Cypress, where there is a pretty good environment. For Nordic you have to put the toolchain together yourself on GCC, but there is a detailed tutorial on how to do that.

@klonyyy You can use ZigBee. It was created for such purposes. Only modules quite expensive, but you can often load your own program onto them.

Thanks for your reply !
The idea is that it should also be a small, portable device, e.g. in the form of a wristband or a watch. So rather Zigbee is out of the question. On the other hand, I don't want to get too much into programming the Bluetooth chips themselves, as this is followed by the cost of the programmer etc (unless you use a bootloader ? ). Nevertheless, do you perhaps know of any BLE chips that are well suited for this purpose ?
Greetings,
Peter

EDIT : However, my understanding of Zigbee was very low (I thought it was just a name for modules adapted for this type of communication, meanwhile it is a standard). I will probably use Zigbee on the cc2530 though. I need to read more about it. Thanks for the guidance