What's needed for Bluetooth (bare bones) functionality

[Ram80]

I want to add Bluetooth functionality, so just the bare chips, no pre assembled board. I need a Bluetooth chip and crystal oscillator. That's all I know so far but I'm sure there's more to it.

Can anybody advise or give a link to a decent article as to what I need to design and add to have functioning in Bluetooth.

I would be using an stm32 MCU, and a 16mb flash ram.

[coppice]

Is this for hobby use or production?

For production stick with BT modules unless you are making millions. The approvals processes cost a lot, and modules can greatly help with the speed and cost of completing that. Because so many people use modules for products selling in large number there is a mature market selling them at low prices. That is, they are sold at "production" rather than specialised prototyping prices.

For hobby use the appropriate choice is really based on your level of masochism.

[glebkooo]

+1 to advice about using BT modules. Designing a proper RF part for the bare chip seems difficult to me.

I would replace stm32 MCU with nRF52840 from Nordic Semiconductor. Nordic provides high quality documentation and a reference design - https://docs.nordicsemi.com/bundle/ps_nrf52840/page/ref_circuitry.html
That will give you an insight of what have to be done to make it functioning. If you would decide to use BT modules, these guys (Holyiot) are selling nRF-based boards of different kinds: https://www.aliexpress.com/store/420533

Another option would be to use, for example, ESP32C3 from Espressif. However, this is WiFi + BT SoC.

[ataradov]

If you are already using STM32, and you actually need a simple IC and not the module, you may want to consider STM32WB55/35.

In addition to what you have listed, you will need an antenna and a matching circuit. And tuning that without specialized equipment is next to impossible. So, unless you already have this, I'd certainly consider using a module.

[coppice]

If you are already using STM32, and you actually need a simple IC and not the module, you may want to consider STM32WB55/35.

In addition to what you have listed, you will need an antenna and a matching circuit. And tuning that without specialized equipment is next to impossible. So, unless you already have this, I'd certainly consider using a module.

You missed expertise. Anyone asking these questions probably doesn't have the relevant microwave expertise.

[Ram80]

+1 to advice about using BT modules. Designing a proper RF part for the bare chip seems difficult to me.

I would replace stm32 MCU with nRF52840 from Nordic Semiconductor. Nordic provides high quality documentation and a reference design - https://docs.nordicsemi.com/bundle/ps_nrf52840/page/ref_circuitry.html
That will give you an insight of what have to be done to make it functioning. If you would decide to use BT modules, these guys (Holyiot) are selling nRF-based boards of different kinds: https://www.aliexpress.com/store/420533

Another option would be to use, for example, ESP32C3 from Espressif. However, this is WiFi + BT SoC.

Good shout on the nRF52840, this is perfect for my needs. Thanks.

I ideally want to keep the design as small as possible. The BT modules add more bulk.