January 8, 2026
Bluetooth - boards with bluetooth
My interest here is in boards I can use to build a bluetooth enabled project.
As much as building a project, I am interested in getting my hands dirty with
bluetooth at a low level.
ESP32
It turns out I already have a good candidate in hand, in the form of my collection
of ESP32 boards.
There is a wide variety of different ESP32 devices and boards.
It turns out that all of them support bluetooth!
I have the ESP-C3-32S, exactly as this excellent tutorial discusses:
The original ESP32 is/was Tensilica based like the ESP8266.
Subsequent versions (like the C3) are riscV based.
None are ARM based.
The generic ESP32 on Amazon are by far the cheapest at under $6 each.
Pi zero W and Pi zero 2 W
The original "zero W" has a single 32 bit ARM core, while the "zero 2 W"
has a quad core 64 bit A53 cpu cluster.
It seems like an obvious choice to get the "zero 2 W" unless there are
thermal issues that the original does not have (as seems likely).
I read that the Pi Zero 2 W will throttle at 80C to protect itself.
This means that few users need a heat sink.
Get something called the FLIRC Zero case, if you need a heatsink as it uses
the case as a heat sink and will avoid throttling under heavy load.
These sell for about $20, whichever you get and have 512M of ram.
They are full blown Cortex-A processors and can run linux.
Whether they are suitable for my interests depends on the availability of
documentation. The "zero 2 W" uses the RP3A0 chip made by Raspberry Pi.
This stacks a Broadcom BCM2710A1 on top of a 512M memory chip, so the
documentation issues will depend on what Broadcom makes available.
In the past, this has been limited, so proceeed with care if you want
to do anything besides run the provided linux.
Adafruit BT friend
Another BT developmnent board is the Adafruit BT LE Friend.
It is not open source, as Adafruit uses a Nordic SDK to build the firmware
they make available for it. It works as a serial device and offers the
AT command set in some form.
If you are just looking to add bluetooth as a "black box" to one of your projects,
this would probably be excellent. In my case where I want a platform to use to learn
bluetooth, it would not be so good.
Have any comments? Questions?
Drop me a line!
Tom's Software pages / tom@mmto.org