Raspberry-stats NPM

Raspberry Stats

A Node.js module for retrieving system information from a Raspberry Pi.
It uses the child_process.spawn command to read various parameters, including CPU temperature, memory usage, disk usage, voltage, and clock frequencies.
Synchronous (callback-based) and asynchronous (promise-based) APIs are provided for each method.

Note: This module relies on vcgencmd and other system commands that are typically available on Raspberry Pi OS. It may not work on other platforms or distributions where these commands are unavailable.

Raspberry Stats

Installation

With npm:

npm install raspberry-stats

With yarn:

yarn add raspberry-stats

With pnpm:

pnpm add raspberry-stats

With bun:

bun add raspberry-stats

Usage

Example using both callback-based and async/await methods:

import {
  getCPUTemperature,
  getCPUTemperatureAsync,
  getMemoryUsage,
  getMemoryUsageAsync,
  // ... other imports
} from "raspberry-stats";

// --- Using callback-based methods ---
// Each callback receives a SystemInfo<T> object containing { data, error }

// Example 1: CPU Temperature
getCPUTemperature((info) => {
  if (info.error) {
    console.error("Failed to retrieve CPU temperature:", info.error);
  } else {
    console.log(`CPU Temperature: ${info.data}°C`);
  }
});

// Example 2: Memory Usage
getMemoryUsage((info) => {
  if (info.error) {
    console.error("Failed to retrieve memory usage:", info.error);
  } else {
    console.log("Memory usage:", info.data);
  }
});

// --- Using promise-based methods (Async/Await) ---
// Each async function returns a Promise<SystemInfo<T>>

(async () => {
  try {
    // Example 1: CPU Temperature
    const tempInfo = await getCPUTemperatureAsync();
    if (tempInfo.error) {
      console.error("Failed to retrieve CPU temperature:", tempInfo.error);
    } else {
      console.log(`CPU Temperature: ${tempInfo.data}°C`);
    }

    // Example 2: Memory Usage
    const memInfo = await getMemoryUsageAsync();
    if (memInfo.error) {
      console.error("Failed to retrieve memory usage:", memInfo.error);
    } else {
      console.log("Memory usage:", memInfo.data);
    }
  } catch (error) {
    console.error(error);
  }
})();

API

Return Format Overview

All callback-based functions receive a single parameter of type SystemInfo<T>:

interface SystemInfo<T> {
  data: T | null;
  error: string | null;
}

data contains the successfully retrieved value (e.g. number, object, or array) if everything went well, otherwise null.
error is a string describing the problem if something failed, otherwise null.

Similarly, all promise-based functions resolve with SystemInfo<T> instead of just the raw data or throwing an error.
Hence, if error is non-null, you can handle it accordingly in your async flow.

getCPUTemperature / getCPUTemperatureAsync

Signature (Callback):

getCPUTemperature(callback: (info: SystemInfo<number>) => void): void;

description
Reads the CPU temperature by running vcgencmd measure_temp.
callback
Receives an object of type SystemInfo<number>.
- info.data is the temperature (in °C) if successful, otherwise null.
- info.error contains an error message if something went wrong, otherwise null.

Signature (Async):

getCPUTemperatureAsync(): Promise<SystemInfo<number>>;

description
Asynchronous/promise-based version of the above function.
Resolves with SystemInfo<number>—check info.error to see if it succeeded.

getCPUUsage / getCPUUsageAsync

Signature (Callback):

getCPUUsage(callback: (info: SystemInfo<number>) => void): void;

description
Runs top repeatedly (e.g., 10 iterations at 0.1-second intervals) and gathers the CPU usage values.
It parses the CPU usage, calculates an average from the samples, and then invokes the callback with the final usage percentage (e.g., 17.2 for ~17.2% usage).
callback
Receives an object of type SystemInfo<number>.
- info.data is the CPU usage or null if it fails.
- info.error is an error message if it fails.

Signature (Async):

getCPUUsageAsync(): Promise<SystemInfo<number>>;

description
Promise-based version.
Resolves with SystemInfo<number>—check info.error to see if it succeeded.

getMemoryUsage / getMemoryUsageAsync

Signature (Callback):

getMemoryUsage(callback: (info: SystemInfo<MemoryUsageResult>) => void): void;

Where MemoryUsageResult is:

interface MemoryUsageResult {
  total: number;
  used: number;
  free: number;
  shared: number;
  buffCache: number;
  available: number;
}

description
Reads memory usage via the free command.
callback
Receives an object of type SystemInfo<MemoryUsageResult>.
- info.data is a MemoryUsageResult object if successful, otherwise null.
- info.error is an error message if something went wrong, otherwise null.

Signature (Async):

getMemoryUsageAsync(): Promise<SystemInfo<MemoryUsageResult>>;

description
Promise-based version.
Resolves with SystemInfo<MemoryUsageResult>—check info.error to see if it succeeded.

getDiskUsage / getDiskUsageAsync

Signature (Callback):

getDiskUsage(callback: (info: SystemInfo<DiskUsageResult[]>) => void): void;

Where DiskUsageResult is:

interface DiskUsageResult {
  filesystem: string;
  oneKBlocks: number;
  used: number;
  available: number;
  usePercentage: number;
  mountedOn: string;
}

description
Reads disk usage info via the df command.
callback
Receives an object of type SystemInfo<DiskUsageResult[]>.
- info.data is an array of disk usage objects if successful, otherwise null.
- info.error is an error message if it fails.

Signature (Async):

getDiskUsageAsync(): Promise<SystemInfo<DiskUsageResult[]>>;

description
Promise-based version.
Resolves with SystemInfo<DiskUsageResult[]>—check info.error on result.

getVoltage / getVoltageAsync

Signature (Callback):

getVoltage(callback: (info: SystemInfo<number>) => void): void;

description
Reads the core voltage by running vcgencmd measure_volts.
callback
Receives an object of type SystemInfo<number>.
- info.data is the voltage (in Volts) if successful, otherwise null.
- info.error is an error message if it fails.

Signature (Async):

getVoltageAsync(): Promise<SystemInfo<number>>;

description
Promise-based version.
Resolves with SystemInfo<number>—check info.error to see if it succeeded.

getClockFrequencies / getClockFrequenciesAsync

Signature (Callback):

getClockFrequencies(
  callback: (info: SystemInfo<ClockFrequencyResult[]>) => void
): void;

Where ClockFrequencyResult is:

interface ClockFrequencyResult {
  clock: string;
  frequency: number | null; // in Hz
}

description
Reads multiple clock frequencies (arm, core, h264, etc.) by running vcgencmd measure_clock.
callback
Receives an object of type SystemInfo<ClockFrequencyResult[]>.
- info.data is an array of clock/frequency objects if successful, otherwise null.
- info.error is an error message if it fails.

Signature (Async):

getClockFrequenciesAsync(): Promise<SystemInfo<ClockFrequencyResult[]>>;

description
Promise-based version.
Resolves with SystemInfo<ClockFrequencyResult[]>—check info.error on result.

getClockFrequency / getClockFrequencyAsync

Signature (Callback):

getClockFrequency(
  clock: Clock,
  callback: (info: SystemInfo<number>) => void
): void;

Where Clock is an enum:

enum Clock {
  ARM = "arm",
  CORE = "core",
  H264 = "h264",
  ISP = "isp",
  V3D = "v3d",
  UART = "uart",
  PWM = "pwm",
  EMMC = "emmc",
  PIXEL = "pixel",
  VEC = "vec",
  HDMI = "hdmi",
  DPI = "dpi",
}

description
Reads the specified clock frequency by running vcgencmd measure_clock.
callback
Receives an object of type SystemInfo<number>.
- info.data is the frequency (in Hz) if successful, otherwise null.
- info.error is an error message if it fails.

Signature (Async):

getClockFrequencyAsync(clock: Clock): Promise<SystemInfo<number>>;

description
Promise-based version.
Resolves with SystemInfo<number>—check info.error on result.

getUptime / getUptimeAsync

Signature (Callback):

getUptime(callback: (info: SystemInfo<number>) => void): void;

description
Reads the system uptime by running awk '{print $1 * 1000}' /proc/uptime.
callback
Receives an object of type SystemInfo<number>.
- info.data is the uptime in milliseconds if successful, otherwise null.
- info.error is an error message if something went wrong.

Signature (Async):

getUptimeAsync(): Promise<SystemInfo<number>>;

description
Promise-based version.
Resolves with SystemInfo<number>—check info.error on result.

Note: The uptime is returned in milliseconds but is based on the system’s uptime in seconds.

Error Handling

Because all the functions return a SystemInfo<T> object, there is no more "rejecting" or passing null—the callback or promise resolves with an object which may contain an error message:

For callback-based methods, check info.error.
If info.error is not null, an error occurred; otherwise info.data contains the good value.
For async methods, check the returned object’s .error property.
If error is non-empty, handle it accordingly; if not, .data contains the requested information.

Example:

// Async example: getCPUTemperatureAsync
(async () => {
  const info = await getCPUTemperatureAsync();
  if (info.error) {
    // something went wrong
    console.error("Failed to read CPU temperature:", info.error);
  } else {
    // success
    console.log(`CPU Temperature: ${info.data}°C`);
  }
})();