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One-page cheat sheet: I want to build X — which board should I buy?
Appendix to "Open Hardware Selection Handbook" · Geek Weidong @GeekWaedon
Price bands: ¥ = under ~¥30, ¥¥ = ¥30-100, ¥¥¥ = over ¥100
Decision tree (find your answer in 30 seconds)
Your first question: does the project need connectivity?
├─ Yes, Wi-Fi/Bluetooth ──→ See [Scenario 1]
└─ Local control / learning only ──→ Second question: will it run on battery for long periods?
├─ Yes, and battery life matters ──→ See [Scenario 3]
└─ Not critical / mains powered ──→ See [Scenarios 2 / 4 / 5]
Three questions for beginners (check before ordering)
- Are there plenty of tutorials in my language? (Search the board — if you find fewer than 10 decent tutorials, beginners should stay away.)
- Do I need to buy a separate programmer to flash it? (Yes for STM32; no for ESP32/Pico.)
- Is the chip powerful enough for my project? (For camera or face-recognition work, think about compute first.)
Scenario quick reference (12 common scenarios)
| What you want to build | First choice | Alternative | Why this one | Pitfall to avoid |
|---|---|---|---|---|
| First IoT project (temp/humidity reporting, remote switches) | ESP32-S3-DevKitC ¥¥ | ESP32-C3 ¥ | The most complete Espressif ecosystem, tutorials everywhere, Wi-Fi and Bluetooth built in | Buy the official DevKit; no-name minimal boards have confusing pin labels |
| Learn embedded fundamentals (GPIO, interrupts, timers) | STM32F103C8T6 ¥ | Arduino UNO R4 ¥¥ | Register-level work forces you to understand the fundamentals; the most mature tutorial ecosystem | Needs a separate ST-Link programmer; watch out for clone chips |
| Battery-powered low power (sensor nodes, portable devices) | Raspberry Pi Pico ¥ | ESP32-C3 ¥ | RP2040 power control is simple and direct; dual cores are plenty | Pico has no Wi-Fi — choose Pico W (¥¥) if you need connectivity |
| Fast validation with the Arduino ecosystem (ready-made module libraries) | Arduino UNO R4 Minima ¥¥ | Nano ESP32 ¥¥ | Unbeatable library ecosystem; everything connects | UNO R4 switched to a Renesas chip and some older libraries are incompatible — check library support before ordering |
| Edge AI inference (faces, object detection) | Sipeed Maixduino ¥¥ | — | The K210 has a built-in NPU, so inference does not depend on the cloud | Compute is limited — do not expect complex models; good for learning and lightweight deployment |
| Motor control / PID (balance bots, gimbals) | STM32F103C8T6 ¥ | STM32F407 ¥¥ | Rich timer resources, good real-time behaviour, plenty of FOC tutorials | Beginners should get open-loop working before closing the loop |
| Industrial / CAN bus (automotive, industrial data acquisition) | STM32F407ZGT6 ¥¥ | — | Native CAN controller | A CAN transceiver (e.g. TJA1050) still has to be added separately |
| Learn RISC-V (instruction set, architecture) | CH32V307 ¥ | GD32VF103 ¥ | Cheap and domestic; enough to learn the RISC-V architecture properly | For a Linux-class RISC-V experience, see the next row |
| RISC-V + Linux (run a real OS) | VisionFive 2 ¥¥¥ | HiFive Unmatched ¥¥¥ | Runs a full Linux distribution, close to PC-style development | Not cheap — only for people who clearly need a RISC-V Linux environment |
| Voice interaction (offline voice control) | ESP32-S3-DevKitC ¥¥ | — | Espressif's official speech solution (ESP-SR) works out of the box | Offline vocabularies are limited; complex intent recognition still needs a cloud solution |
| Try a new protocol (NearLink) | NearLink DevKit Pro ¥¥ | Sensor Node ¥¥ | The NearLink ecosystem is still early — joining now means a content opportunity | Few resources and a young ecosystem; suitable for experienced makers, not beginners |
| LoRa long-range communication (hundreds of metres to several kilometres) | ESP32-S3 + LoRa module ¥¥ | — | Add an SX1276 module to a Scenario 1 board — no need to change boards | Check local ISM band rules (470 MHz in China) |
What you learn only after buying
- Bought an STM32 and then found out: you still need a debugger, jumper wires and a breadboard — the real entry cost doubles
- Bought a RISC-V Linux board and then found out: the project you wanted to build would have run fine on an ESP32 — you paid ten times more for architectural enthusiasm
- Bought a Pico and then found out: you need an external module for connectivity — you should have bought a Pico W from the start
- Bought a no-name ESP32 and then found out: the USB-serial chip was cut corners and even the Windows driver will not install — the official DevKit costs a little more and buys peace of mind
How this sheet relates to the handbook
This sheet is a condensed version of the "Open Hardware Selection Handbook". The full handbook covers detailed pitfalls for every board, complete breakdowns of 8 hands-on projects, a toolchain setup checklist and how to identify genuine parts when buying.
Chapter 1 is free to read: "The Right Order of Selection". The handbook is updated continuously — to get new chapters and hands-on notes first, join the Knowledge Planet community "Geek Weidong".
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