Your microcontroller’s files, one `open()` away – over Bluetooth LE

What if the SD card or LittleFS partition of your ESP32 looked like a folder on your other devices, without Wi-Fi, a web server or a USB cable? TinyBLEFS joins a family of small, header-only libraries for moving data on and off Arduino boards: TinyNBD exports their storage as a linux network block device, TinyFTP reads and writes remote files over FTP (client and server) and TinySMB shares them with Windows, macOS and Linux as Read more

By pschatzmann, ago

The Cheapest DNS Server You Will Ever Own

How a microcontroller the size of a postage stamp can name, find, and resolve everything on your network. Names are the quiet superpower of networks Every time you type a web address, an invisible conversation happens. Your device asks, “Where does this name live?” and somebody answers with a number. That somebody is a DNS server, and we usually imagine it as serious infrastructure: a rack in a data center, a router with a big Read more

By pschatzmann, ago

Turn a $5 Microcontroller into a USB WiFi Dongle, in Four Lines

Your PC has no WiFi, or its WiFi card is flaky, or you just want a cheap, hackable network adapter. You probably have an ESP32-S3 or a Pico 2 W in a drawer. TinyWifiDongle turns it into a USB WiFi dongle: #include “TinyWifiDongle.h” TinyWifiDongle dongle; void setup() { dongle.begin(“ssid”, “password”); } void loop() {} Flash it, plug it in, and your PC sees a normal network adapter. No driver is needed, because Linux, macOS and Read more

By pschatzmann, ago

Your Phone as a Time Server for Arduino

Every microcontroller project that logs data, schedules actions or shows a clock eventually needs to know the time. Getting it right is surprisingly hard: internal clocks drift, RTC modules need to be set, and NTP needs internet access, which you often don’t have in the field, in a workshop or on a battery-powered sensor. Yet the answer is probably in your pocket. A smartphone knows the time very precisely, from the network and from its Read more

By pschatzmann, ago

The Quiet Heartbeat: Time, Microcontrollers and the Things We Build

“Time is what keeps everything from happening at once.” — Ray Cummings Every microcontroller has a heartbeat. A quartz crystal vibrates millions of times per second, a counter ticks upward, and the board always knows how long it has been since it woke up. But ask a freshly powered ESP32 what time it is, and it has no idea. It knows duration, not moment. It can count, but it can’t tell you whether it’s Tuesday Read more

By pschatzmann, ago

TensorFlow Lite Micro on Arduino: Filling the Gap Until There Is an Official Package Again

If you want to run a TensorFlow Lite model on an Arduino today, you quickly find that there is no obvious answer. There used to be one: Google’s official Arduino package, Arduino_TensorFlowLite, built from tflite-micro-arduino-examples. That package has not been updated for a long time, and I think it is worth looking at how we got here and what you can use in the meantime. What happened to the official package The official package was Read more

By pschatzmann, ago

TinyModem: Sending Data Through Sound with an ESP32 or a Raspberry Pi Pico

Remember the screeching of the dial-up modem? Turning data into sound is still one of the simplest ways to connect devices: you can use an audio cable, send it from a speaker to a microphone, put it on a telephone line or a radio, or just store it in a WAV file. No Wi-Fi, no pairing, no extra hardware. TinyModem is a header-only C++ library of software audio modems for Arduino and the desktop. It Read more

By pschatzmann, ago

TinySTT: Speech-to-Text on a Microcontroller – a Proof of Concept

If you look for speech recognition examples for microcontrollers, you almost always end up with wake word detection or keyword spotting: the micro_speech example of TensorFlow Lite Micro, which recognizes “yes” and “no”; Espressif’s ESP-SR with WakeNet for the wake word and MultiNet for a list of commands; keyword spotting models trained with Edge Impulse; or Picovoice’s Porcupine and Rhino. They work well for what they do, but they all classify a small, fixed set Read more

By pschatzmann, ago

Arduino Audio Tools: Streaming Video and Audio via HTTP

If you have ever streamed video from an ESP32, you have most likely used the CameraWebServer example: the camera delivers JPEG images, which the web server pushes one after the other to the browser. This works, but there is no sound, the bandwidth is high, and the result is not a real video stream that you could record or play in VLC. A real stream needs a video codec such as H.264, an audio codec Read more

By pschatzmann, ago

The Cheapest Way to Run a Neural TTS

Classic embedded text-to-speech (formant synthesizers like SAM or eSpeak) is tiny and fast, but it sounds like a robot from the 80s. Neural TTS sounds natural, but it is usually something you run on a PC or in the cloud. I wanted to know: what is the cheapest hardware that can run a neural text-to-speech model locally, faster than real time? To find out I ported tiny-tts to C++ as TinyTTS. It is a VITS-style, Read more

By pschatzmann, ago