The connected kit

A development board is a small chip mounted on a little circuit board, with a USB socket and rows of pins. You can program it from your computer and plug wires into it. You may well own one already: an ESP32-S3 board, plus a breadboard, a temperature sensor and a small screen. Those carry most of this course.

This course adds three things to that kit. Together they are the connected kit.

First, a second kind of ESP32 board, the ESP32-C6. Its radio is newer, and a later part of the course uses it for programs written in Rust.

Second, any spare ESP32 board. Some labs need two devices talking directly to each other, and you can't do that with one.

Third, your own computer. It plays a real role. It runs the program that collects messages from your boards, and the programs that store and show them. You don't need to rent anything.

Everything else in the table is optional. A few optional parts cost money every month, such as a mobile data plan. Prices here are only rough ranges, checked in October 2026, because they change from shop to shop and month to month. Buy from the board maker or a shop it lists, and download the board's documentation before you order.

The connected kit is the hardware this course's labs use, on top of the starter kit a reader of embedded-systems owns. A development board is a microcontroller module mounted on a small circuit board with a USB connector, a voltage regulator and pin headers, so it can be programmed and wired on a breadboard. Most of this course needs only the items marked required.

Your computer is a real part of the kit. It runs Mosquitto, the message server most labs send readings to, and the Python programs that store and display them. Nothing in a required lab depends on a paid service or on someone else's server.

Prices change by country, seller and month, so they appear here only as rough bands, checked in October 2026:

Buy from an authorized distributor or the board maker's own store, and download the board's documentation before you order it.

Espressif, the company that makes ESP32 chips, sells a whole family of them. They differ in two ways that matter here: which radios they have, and what kind of processor runs your program.

The table is our best knowledge in October 2026. Check each fact on Espressif's own product page before you rely on it. Chips get updated, and the software around them changes faster still.

There are three reasons to add an ESP32-C6.

Its Wi-Fi is newer, called Wi-Fi 6. One Wi-Fi 6 feature lets a device and the router agree on when the device will next wake up. Between those times the device can sleep, which saves battery. It only works if your router is a Wi-Fi 6 model that supports the feature too.

It has a second radio of a kind the S3 lacks, called 802.15.4. That's a low-power radio used by home-automation systems such as Thread and Zigbee. Chapter 7 uses it.

And its processor is a kind called RISC-V. The Rust programming language supports RISC-V directly, so the later Rust chapters can use the normal Rust tools. The S3's processor needs a special version of them.

One last fact: both boards use only 2.4 GHz Wi-Fi. If your router also has a 5 GHz network, the boards can't see it.

Espressif's chips differ mainly in their radios and their processor cores, and both decide what a lab can do. The table below is working knowledge as of October 2026. Confirm each row on Espressif's product page and the chip's datasheet before you rely on it: chips gain revisions, and the software support around them changes faster than the silicon.

Three reasons put the ESP32-C6 in the kit.

1. Wi-Fi 6. Its 802.11ax radio supports Target Wake Time, where a device and an access point agree when the device will next wake. A sleeping sensor can then skip beacons it doesn't need. It helps only if your access point also speaks Wi-Fi 6 and supports the feature.
2. An 802.15.4 radio, the low-power radio standard under Thread and Zigbee, which Chapter 7 uses. The S3 has none.
3. RISC-V cores. The Rust compiler supports RISC-V out of the box, so Chapters 17 and 18 build ESP32-C6 firmware with the ordinary, stable Rust toolchain. The S3's Xtensa cores need a separate fork.

Both boards run 2.4 GHz Wi-Fi only. A home router's 5 GHz network is invisible to them, which matters in Chapter 4.

Two optional radios come with strings attached.

LoRa sends small messages a very long way, several kilometres, on very little power. It uses radio bands that anyone may use without a license. But each part of the world has its own band. Europe uses around 868 MHz, and the United States around 915 MHz. A LoRa module is built for one band, so buy one sold for your country.

Europe also limits how much of the time a device may transmit, often 1 percent. That's 36 seconds of sending per hour. Chapter 7 shows what fits in that.

Cellular radios, called LTE-M and NB-IoT, use the same phone networks as your mobile phone. So each device needs a SIM card and a data plan, and that plan costs money every month, for every device. A board you buy once doesn't.

These radio rules are law in each country, not tips. Using the wrong module, or sending too much, is illegal.

Two optional radios come with conditions that Wi-Fi and Bluetooth don't.

LoRa is a long-range, low-data-rate radio that works in unlicensed bands, and the band depends on where you live: 863–870 MHz in Europe, 902–928 MHz in the United States, other ranges elsewhere. A module is built for one band, so buy one sold for your region. In Europe's 868 MHz band, the rules also limit duty cycle, the fraction of time a device may transmit: commonly 1% in the sub-bands LoRaWAN uses, which is 36 s of airtime per hour. Chapter 7 §4 works through what that allows.

Cellular IoT (LTE-M, NB-IoT) uses a mobile operator's network, so a device needs a SIM and a data plan. That is a recurring cost, paid every month for every device, unlike a board you buy once. Check that your operator supports the technology where you live; coverage differs by country.

Radio rules are national law, not advice. A module sold for the wrong region, or a device that transmits more than its band allows, is illegal to operate there.