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Two Kings · Act 5 · Now and next

Bluetooth and Arduino today: the story so far

The research behind 33:42–38:50 of the film · Watch this part

Today Bluetooth means Low Energy: the HC-05's kind of Bluetooth, Classic on its own, is fading, and by 2030 ninety-nine out of every hundred Bluetooth devices shipped will speak Low Energy.2 LE Audio added broadcast with Auracast, version 6.0 added Channel Sounding to measure the distance between two devices, and the newest version is 6.3, from May 2026.5711 Arduino moved with it: the Uno R4 WiFi gets its Bluetooth from an Espressif chip that speaks only Low Energy, and in October 2025 Qualcomm agreed to buy Arduino.151620

Key facts

  • In 2025 alone, more than seventy-nine thousand new Bluetooth products were certified.3
  • LE Audio was announced in 2020 and finished in 2022. With Auracast, one transmitter can send sound to any number of earbuds or hearing aids, with no pairing at all.45
  • In January 2026 Frankfurt Airport began a trial at two gates, sending its gate announcements straight into passengers' own hearing aids and earbuds.6
  • Channel Sounding aims for accuracy to a few centimetres; the first devices manage to within about twenty. The first phone to support it, Google's Pixel 10, arrived in August 2025.7910
  • Matter, the smart-home standard, leans on Bluetooth: setting up a new light or lock usually starts over Low Energy.13
  • The Uno R4 WiFi, from 2023, has an ESP32-S3 beside the main chip. It speaks only Low Energy: Classic Bluetooth, the HC-05's link, isn't on the modern Uno at all.1416
  • Qualcomm agreed to buy Arduino in October 2025, the day the UNO Q launched with Wi-Fi and Bluetooth built in, and counted more than thirty-three million active Arduino users.202122

28

facts cited

46

sources, 37 primary

5

common claims corrected

1

archival images

What this part says

The narration, line by line, as it is spoken in the film.

Scale

A city at dusk. Watches, earbuds, lamps and keys: small things, waking up and finding each other without a wire.

Harald's name is on more of them every year, and the bench's old question, Classic or Low Energy, is being answered.12

Last year about five and a half billion Bluetooth devices shipped. This year it will be close to six billion, and by 2030 more than eight billion a year.1

In 2025 alone, more than seventy-nine thousand new Bluetooth products were certified.3

The spine resolved

The HC-05's kind of Bluetooth, Classic on its own, is fading. By 2030, ninety-nine out of every hundred Bluetooth devices shipped will speak Low Energy.2

The radio that was added beside the old one has become the radio.

Broadcast

LE Audio was announced in 2020 and finished in 2022.4

It brought something Bluetooth never had: broadcast. With Auracast, one transmitter can send sound to any number of earbuds or hearing aids, with no pairing at all.5

In January 2026, Frankfurt Airport began sending its gate announcements straight into passengers' own hearing aids and earbuds, at two gates, as a trial.6

No code. No 1234. The pairing ritual is gone.

Auracast is also in the Sydney Opera House, Bristol Temple Meads station and St Paul's Cathedral.6

Knowing where

Broadcast changed who can listen. The next change is about distance: not whether something is nearby, but exactly how far away it is.

In 2024, version 6.0 added Channel Sounding, which lets two devices measure the distance between them.7

It sends tones back and forth across many channels. A tag can tell you how far away your keys are, and a car door can refuse to open unless the phone really is next to it.8

The goal is accuracy to a few centimetres, and the first devices manage about twenty. The first phone to support it, Google's Pixel 10, arrived in August 2025.910

As this film was made, the newest version of Bluetooth was 6.3, from May 2026.11

It's still refining that same trick: knowing exactly where things are.12

The quiet job

Even the new smart-home standard, Matter, leans on Bluetooth: when you set up a new light or lock, the first conversation usually happens over Low Energy.13

Arduino's bench today

In 2023 even the classic Uno got a radio: the Uno R4 WiFi, with an Espressif chip beside the main one, driven by Arduino's own Bluetooth library.1415

That chip speaks only Low Energy. The serial link the HC-05 used, Classic Bluetooth, isn't on the modern Uno at all.16

By 2023 Espressif had shipped more than a billion chips. And by 2021, Arduino said more than ten million Unos had been sold, not counting the clones.1718

A month after the new Uno came the Nano ESP32, with Espressif's chip at its heart.19

The new owner

In October 2025 Qualcomm agreed to buy Arduino, and a new Uno launched the same day: the UNO Q, half Linux computer, half microcontroller, with Wi-Fi and Bluetooth built in.2021

When it announced the deal, Qualcomm counted more than thirty-three million active Arduino users.22

The company that started in a bar in Ivrea is now part of a chip giant. It has promised that what was open stays open.2324

In 2026 came a bigger sibling for robotics, the VENTUNO Q, with Bluetooth built in.25

Next

The next version, expected before the end of 2026, is set to make Low Energy almost four times faster. And engineers are already working on taking Bluetooth beyond the 2.4 gigahertz band it has lived in since 1999.2627

Into five and six gigahertz.27

Stories that are usually told wrong

Common questions

What is Auracast?

LE Audio brought something Bluetooth never had: broadcast. With Auracast, one transmitter can send sound to any number of earbuds or hearing aids, with no pairing at all. In January 2026, Frankfurt Airport began sending its gate announcements straight into passengers' own hearing aids and earbuds, at two gates, as a trial.56

What is the latest version of Bluetooth?

As this film was made, the newest version of Bluetooth was 6.3, from May 2026. The next version, expected before the end of 2026, is set to make Low Energy almost four times faster.1126

What is Bluetooth Channel Sounding?

In 2024, version 6.0 added Channel Sounding, which lets two devices measure the distance between them. Channel Sounding measures distance by sending tones back and forth across many channels. A tag can tell you how far away your keys are, and a car door can refuse to open unless the phone really is next to it. The goal is accuracy to a few centimetres; the first devices manage to within about twenty.789

Does the Arduino Uno R4 WiFi have Bluetooth?

Yes, Low Energy only. On the Uno R4 WiFi, the Bluetooth comes from the Espressif chip beside the main one, and Arduino's own Bluetooth library drives it. That chip speaks only Low Energy. The serial link the HC-05 used, Classic Bluetooth, isn't on the modern Uno at all.1516

Did Qualcomm buy Arduino?

It agreed to, in October 2025. In October 2025 Qualcomm agreed to buy Arduino, and a new Uno launched the same day: the UNO Q, half Linux computer, half microcontroller. The company that started in a bar in Ivrea is now part of a chip giant. It has promised that what was open stays open.202324

Is Classic Bluetooth going away?

The HC-05's kind of Bluetooth, Classic on its own, is fading. By 2030, ninety-nine out of every hundred Bluetooth devices shipped will speak Low Energy.2

The facts and their sources

Primary sources come first: the organisation, person or document itself. Secondary sources are reputable press or reference works.

  1. 1

    Last year about five and a half billion Bluetooth devices shipped. This year it will be close to six billion, and by 2030 more than eight billion a year.

  2. 2

    The HC-05's kind of Bluetooth, Classic on its own, is fading. By 2030, ninety-nine out of every hundred Bluetooth devices shipped will speak Low Energy.

  3. 3

    In 2025 alone, more than seventy-nine thousand new Bluetooth products were certified.

  4. 4

    LE Audio was announced in 2020 and finished in 2022.

    Often told as: LE Audio arrived in 5.2 in 2020.
    Why that is not right: Announced at CES in January 2020 with Core 5.2 (isochronous channels). The full specifications (LC3, Auracast) were completed on 12 July 2022.
  5. 5

    LE Audio brought something Bluetooth never had: broadcast. With Auracast, one transmitter can send sound to any number of earbuds or hearing aids, with no pairing at all.

  6. 6

    In January 2026, Frankfurt Airport began sending its gate announcements straight into passengers' own hearing aids and earbuds, at two gates, as a trial.

  7. 7

    In 2024, version 6.0 added Channel Sounding, which lets two devices measure the distance between them.

    Often told as: Channel Sounding measures distance to within centimetres.
    Why that is not right: Centimetres is the design goal; early devices manage about ±20 cm.
  8. 8

    Channel Sounding measures distance by sending tones back and forth across many channels. A tag can tell you how far away your keys are, and a car door can refuse to open unless the phone really is next to it.

  9. 9

    The goal is accuracy to a few centimetres; the first devices manage to within about twenty.

    Often told as: Channel Sounding measures distance 'to within centimetres'.
    Why that is not right: The SIG says it is 'expected' to reach centimetre-level accuracy and that 'early implementations' show about ±20 cm. Nordic's phone demo reported ±1 m out to 20 m.
  10. 10

    The first phone to support it, Google's Pixel 10, arrived in August 2025.

  11. 11

    As this film was made, the newest version of Bluetooth was 6.3, from May 2026.

  12. 12

    The current version as this film was made is 6.3, released in May 2026, and it is still refining that same trick: knowing exactly where things are.

  13. 13

    Even the new smart-home standard, Matter, leans on Bluetooth: when you set up a new light or lock, the first conversation usually happens over Low Energy.

  14. 14

    In 2023 even the classic Uno got a radio: the Uno R4 WiFi, with an ESP32-S3 beside the main chip.

  15. 15

    On the Uno R4 WiFi, the Bluetooth comes from the Espressif chip beside the main one, and Arduino's own Bluetooth library drives it.

  16. 16

    That chip speaks only Low Energy. The serial link the HC-05 used, Classic Bluetooth, isn't on the modern Uno at all.

  17. 17

    By 2023 Espressif, the company behind the ESP32, had shipped more than a billion chips.

    Often told as: The ESP32 dominates the maker bench.
    Why that is not right: No primary or neutral source measures a share of the maker market, so 'dominates' is dropped. Espressif, 22 Sep 2023: cumulative shipments 'exceeded one billion', counted from the ESP8266 (2014), so this covers its Wi-Fi-only chips too.
  18. 18

    By 2021, Arduino said more than ten million Unos had been sold, and that doesn't count the clones.

    Often told as: 10 million Unos.
    Why that is not right: Arduino blog 24 Nov 2021: 'The UNO has now sold over 10 million units.' Blog 9 Dec 2021: 'The UNO itself ... has recently crossed the 10 million mark.' The 2023 R4 launch post rephrases it as 'over 10 million users' of the R3.
  19. 19

    A month after the new Uno, Arduino put Espressif's chip at the heart of a Nano: the Nano ESP32.

  20. 20

    In October 2025 Qualcomm agreed to buy Arduino, and a new Uno launched the same day: the UNO Q, half Linux computer, half microcontroller.

  21. 21

    The UNO Q has Wi-Fi and Bluetooth built in, with no module to wire.

  22. 22

    When Qualcomm announced the deal, it counted more than thirty-three million active Arduino users.

    Often told as: Arduino has 'millions of users'.
    Why that is not right: The 33 million figure is Qualcomm's (press release, 7 Oct 2025, quoted by EE Times: 'over 33 million active users in the Arduino community'). Arduino itself only says 'a community of millions' (arduino.cc home) and 'our community of millions of developers' (Qualcomm FAQ).
  23. 23

    The company that started in a bar in Ivrea is now part of a chip giant.

  24. 24

    It has promised that what was open stays open.

  25. 25

    In 2026 came a bigger sibling for robotics, the VENTUNO Q, with Bluetooth built in.

  26. 26

    The next version, expected before the end of 2026, is set to make Low Energy almost four times faster.

  27. 27

    Engineers are already working on taking Bluetooth beyond the 2.4 gigahertz band it has lived in since 1999, into 5 and 6 gigahertz.

  28. 28

    In 2006 Nokia announced its own low-power radio, Wibree. A year later it agreed to fold it into Bluetooth, and in 2010 it came back as Bluetooth Low Energy, the headline of version 4.0.

The images

Real photographs and documents used in this part, with their credits and licences. Tap one to see the original.

Arduino UNO R4 WiFi (2023), with its LED matrix
Arduino UNO R4 WiFi (2023), with its LED matrixLomrjyo / Wikimedia Commons / CC BY-SA 4.0

Dramatised scenes

Places, people and eras for which no footage exists, reconstructed for the film. They are marked DRAMATISATION on screen.

A city at dusk from high above; windows light up one by one.
DramatisationA city at dusk from high above; windows light up one by one.
A grid of apartment windows at dusk; lights switch on in a few.
DramatisationA grid of apartment windows at dusk; lights switch on in a few.
A wrist on a desk edge at dusk, a plain round watch's glow pulsing.
DramatisationA wrist on a desk edge at dusk, a plain round watch's glow pulsing.
A white earbud case on a desk by the window; its tiny status light pulses.
DramatisationA white earbud case on a desk by the window; its tiny status light pulses.
Wrists on a tram's handrail at dusk: watches and bands, all plain.
DramatisationWrists on a tram's handrail at dusk: watches and bands, all plain.
The city at night, fully lit, lights twinkling in the haze.
DramatisationThe city at night, fully lit, lights twinkling in the haze.
An airport gate seen from behind the seated travellers; a white aircraft outside.
DramatisationAn airport gate seen from behind the seated travellers; a white aircraft outside.
Close from behind on a traveller's ear with a small white earbud.
DramatisationClose from behind on a traveller's ear with a small white earbud.
Close from behind on a traveller's ear with a small beige hearing aid, silver hair.
DramatisationClose from behind on a traveller's ear with a small beige hearing aid, silver hair.
A departure board as glowing bars, out of focus; an earbud in the foreground.
DramatisationA departure board as glowing bars, out of focus; an earbud in the foreground.
Keys and a small white tag on a hall table; a patch of morning sun slides across them.
DramatisationKeys and a small white tag on a hall table; a patch of morning sun slides across them.
A hand reaches for a car's door handle in a parking garage at night.
DramatisationA hand reaches for a car's door handle in a parking garage at night.
A plain smart bulb in a desk lamp warms up; the dusk window behind.
DramatisationA plain smart bulb in a desk lamp warms up; the dusk window behind.
The maker's bench at dusk; the desk lamp switches on.
DramatisationThe maker's bench at dusk; the desk lamp switches on.
A glass office tower at dusk, floors lit.
DramatisationA glass office tower at dusk, floors lit.
40:58
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Two Kings: a history of Arduino and Bluetooth

This part starts at 33:42. The full film is 40:58 long: two kings, a radio, a board, and how they ended up on the same bench.

Watch from 33:42

All sources

Two Kings: a history of Arduino and Bluetooth, by Troniction. The Bluetooth® word mark and logos are registered trademarks owned by Bluetooth SIG, Inc. Arduino® is a trademark of Arduino S.r.l. Neither endorses this film. Image credits and licences are listed with each image.