Okapi_Library

An Arduino-compatible library for utilizing the basic and logging features of the Okapi data logger.

Data-logger management. Basic operations, power management, on-board sensing, and links to external devices. Manages logging, power, telemetry, and on-board sensing for the Okapi data logger. Supports solar charging, Particle Boron telemetry, external interrupt counting, RTC-driven sleep/wake cycles, and SD-card data logging.

Since 2026-09-23 Okapi is built on NW_Logger, the logger core it shares with Margay. That gives it Margay’s card layout (/<SN>/log00001.csv and sta00001.csv, HWTest.txt; the old NW/<SN>/Logs/LogN.txt is gone), the status file with watch(sensor), note(word) and the Note column, its serial number from Page 0 when the board is provisioned (NW-Provision) and from the last 8 bytes of EEPROM otherwise, and the camelCase names (run, logStr, addDataPoint, initLogFile, resetWDT, powerAuto, powerAux, i2cState, getVoltage, setVoltage, readStr). The PascalCase names still compile as deprecated forwarders for one release. begin() still returns whether the self-tests passed.

Installation: included in NorthernWidget-libraries.

#include <Okapi.h>

Okapi logger;

String update() {
  // Return a comma-separated string of external sensor readings.
  // Example: return myExternalSensor.getString();
  return "";
}

void setup() {
  Serial.begin(38400);
  if (!logger.begin("ExternalData,")) {
    Serial.println("begin() reported an error; check LED color for details.");
  }
}

void loop() {
  logger.run(update, 60);
}

See examples/ for this demo.

Full API reference: https://docs.northernwidget.com/Okapi_Library/