🛠 Découvrir l'Arduino Tian : un microcontrôleur et un vrai Linux sur la même carte

Objectives

Understand the unique architecture of the Arduino Tian: two brains on one board — an Atmel/Microchip SAMD21 microcontroller (ARM Cortex-M0+, family clocked up to 48 MHz) that runs your Arduino sketches, and a Qualcomm Atheros AR9342, a MIPS processor running up to 533 MHz with a dual-band 2.4/5 GHz IEEE 802.11n 2x2 WiFi module, which runs a Linux distribution based on OpenWRT named Linino. First upload, first serial message.

Hardware

• 1 Arduino Tian board (platform now discontinued: packages remain available, official documentation is archived at docs.arduino.cc/retired)
• 1 micro-USB data cable (some cables are charge-only!)
• On Windows, the official guide requires installing a package (.bin file) that creates a virtual COM port each time the Tian is connected: this is the port you must select in the IDE
• Arduino IDE with the "Arduino Tian (Xiao Tian)" board package installed via the Board Manager

Complete Code

// Blink sur Tian : le croquis tourne sur le SAMD21, pas sur Linux.
const uint8_t LED = 13;   // broche de la LED embarquée

void setup {
  pinMode(LED, OUTPUT);
  Serial.begin(9600);     // port série du SAMD21
}

void loop {
  digitalWrite(LED, HIGH);
  delay(500);
  digitalWrite(LED, LOW);
  delay(500);
  Serial.println(F("ping depuis le SAMD21"));
}

In the IDE: Tools > Board > Arduino Tian, select the port indicated by the installation guide, then Upload.

Expected Verification

The LED blinks at 1 Hz as soon as the upload finishes and the Serial Monitor displays the "ping" messages. Key point: the sketch runs on the SAMD21 while Linux boots on its side — the two systems are independent as long as you do not use the Bridge.

Common Errors

• Looking for a serial port "like on an UNO": on Windows, enumeration goes through the virtual COM port created after installing the package, as explained in the official Tian installation guide.
• Confusing the two brains: an infinite loop on the sketch side does not stop Linux, and Linux keeps running even if your sketch crashes.
• Forgetting that the platform is end-of-life: no more patches for Linino; never expose the board directly to the Internet.
• >