🛠 Fonctionner sur batterie LiPo et économiser l'énergie

Objectives

Power the MKR WiFi 1010 with a single-cell 3.7 V LiPo (JST connector, ≥1024 mAh recommended) using the onboard charger — the PMIC is the TI BQ24195L (enable with the flag -DUSE_BQ24195L_PMIC) — and build an energy-efficient cycle: measure, transmit a WiFi burst, and sleep (__WFI) until an external interrupt. Critical reminders: the ON LED stays off when running on battery (5 V rail) and VIN accepts only regulated 5–6 V, not the raw 6–12 V used by Arduino AVR boards.

Hardware

• 1 × Arduino MKR WiFi 1010
• 1 × single-cell 3.7 V LiPo battery (JST PH 2-pin, respect +/− polarity)
• Button on an external interrupt pin (e.g., A1, pin 16) for wake-up
• Multimeter for the energy budget
• >

Complete code

#include <WiFiNINA.h>
const uint8_t PIN_WAKE = A1;   // pin 16, interruption externe possible

void setup {
  Serial.begin(115200);
  pinMode(PIN_WAKE, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(PIN_WAKE), reveil, FALLING);
}

void reveil { /* reveille le SAMD21 via __WFI */ }

void loop {
  // 1) Rafale : lecture capteur + envoi rapide
  Serial.println("mesure...");
  // ... lecture ADC, connexion WiFi, envoi, WiFi.end ...
  WiFi.disconnect;
  WiFi.end;                    // coupe la radio NINA, gros gain

  // 2) Sommeil : le CPU attend l'interruption (broche 0,1,4,5,6,7,8,9,
  //    16/A1, 17/A2 supportent les interruptions externes).
  noInterrupts;
  if (digitalRead(PIN_WAKE) == HIGH) {  // pas d'appui deja en cours
    __WFI;
  }
  interrupts;
  delay(100);
}

Expected verification

On battery, the board works even though the ON LED is off (normal behavior, official FAQ). The button wakes the board: the monitor (if USB is connected for testing) displays a new measurement. When unplugging USB, the measurable current drops after WiFi.end — the radio is the primary power consumer.

Common errors

• Panicking when seeing the ON LED off on battery: it is wired to the 5 V rail, not the battery — this is intended.
• Injecting 9 V or unregulated voltage into VIN: input is regulated 5–6 V only; exceeding this damages the regulator.
• Forgetting WiFi.end before sleeping: the NINA module consumes heavily as long as the radio remains active.
• Wake-up not working: not all pins support external interrupts (list: 0, 1, 4, 5, 6, 7, 8, 9, 16/A1, 17/A2) and you must re-arm attachInterrupt after certain wake-up paths.
• >
• Battery stored discharged below the PMIC recharge threshold: the board will not power on; recharge it on a bench charger.