KX134 accelerometer and Raspberry Pi Pico Arduino example

In this article we connect the ever popular KX134 accelerometer to a raspberry Pi Pico and we will then display readings via the serial monitor window. We are using the Arduino IDE.

Lets look at the sensor first

Features

• Measurement Range: ±8g, ±16g, ±32g, ±64g (User Selectable)
• High Resolution (8 or 16-bit)
• User-Configurable Output Data Rate (ODR) up to 25600Hz
• User-Configurable 3-stage Advanced Data Path featuring low-pass filter, low-pass/high-pass filter and RMS calculation engine
• Wide range of built-in sensing functions
  • Free Fall
  • Directional-Tap^™ / Double-Tap^™
  • Device Orientation & Activity Algorithms
• Low Noise: 130µg/√Hz (varies based on ODR, power mode & other settings)
• High-Resolution Wake-Up & Back-to-Sleep Detection with a configurable threshold as low as 3.9mg
• 512-byte FIFO buffer that continues recording data while being read
• Selectable Low-Power or High-Performance operating modes
• Low Power with Integrated Voltage Regulator
  • High-Performance Operating Current Consumption (400Hz ODR + Wake-Up Detection): 148µA
  • Low Power Operating Current Consumption (0.781Hz ODR + Wake-Up Detection): 0.53µA
  • Standby Current Consumption: 0.5µA
• Self-Test Functionality
• Digital I²C up to 3.4MHz and Digital SPI up to 10MHz
• 2x Qwiic Connectors
• SPI available on PTH Header Pins
• I²C Address: 0x1E (0x1F alternate)

Parts Required

Name	Link
Raspberry Pi Pico		Aliexpress link Amazon Ebay
KX134		Aliexpress link Ebay link
Connecting cables		Aliexpress link Amazon Ebay

Schematic/Connection

Here is a layout in fritzing to show this

Code Example

I used the Sparkfun KX13X library and  this is the default example which worked, there are several examples to experiment with

#include <Wire.h>
#include <SparkFun_KX13X.h> // Click here to get the library: http://librarymanager/All#SparkFun_KX13X

//SparkFun_KX132 kxAccel;
SparkFun_KX134 kxAccel; // For the KX134, uncomment this and comment line above

outputData myData; // Struct for the accelerometer's data

void setup()
{

  Wire.begin();

  Serial.begin(115200);
  Serial.println("Welcome.");

  // Wait for the Serial monitor to be opened.
  while (!Serial)
    delay(50);

  if (!kxAccel.begin())
  {
    Serial.println("Could not communicate with the the KX13X. Freezing.");
    while (1)
      ;
  }

  Serial.println("Ready.");

  if (kxAccel.softwareReset())
    Serial.println("Reset.");

  // Give some time for the accelerometer to reset.
  // It needs two, but give it five for good measure.
  delay(5);

  // Many settings for KX13X can only be
  // applied when the accelerometer is powered down.
  // However there are many that can be changed "on-the-fly"
  // check datasheet for more info, or the comments in the
  // "...regs.h" file which specify which can be changed when.
  kxAccel.enableAccel(false);

  //kxAccel.setRange(SFE_KX132_RANGE16G); // 16g Range
  kxAccel.setRange(SFE_KX134_RANGE16G);         // 16g for the KX134

  kxAccel.enableDataEngine(); // Enables the bit that indicates data is ready.
  // kxAccel.setOutputDataRate(); // Default is 50Hz
  kxAccel.enableAccel();
}

void loop()
{
  // Check if data is ready.
  if (kxAccel.dataReady())
  {
    kxAccel.getAccelData(&myData);
    Serial.print("X: ");
    Serial.print(myData.xData, 4);
    Serial.print(" Y: ");
    Serial.print(myData.yData, 4);
    Serial.print(" Z: ");
    Serial.print(myData.zData, 4);
    Serial.println();
  }
  delay(200); // Delay should be 1/ODR (Output Data Rate), default is 1/50ODR
}

Output

Move the sensor in various directions to test

X: 0.0273 Y: -0.4626 Z: -0.8560
X: 0.0073 Y: -0.4831 Z: -0.8623
X: 0.0595 Y: -0.4431 Z: -0.8535
X: 0.0063 Y: -0.4758 Z: -0.8799
X: -0.0229 Y: -0.2689 Z: -0.6803
X: -0.0605 Y: -0.3026 Z: -0.9199
X: -0.1147 Y: -0.4197 Z: -0.9062
X: -0.7745 Y: -0.2235 Z: 0.3777
X: -0.2991 Y: -1.1151 Z: -0.4099

Links

https://github.com/sparkfun/SparkFun_KX13X_Arduino_Library

https://fscdn.rohm.com/kionix/en/datasheet/kx134-1211-e.pdf