The MMA7455L is a Digital Output (I2C/SPI), low power, low profile capacitive micromachined accelerometer featuring signal conditioning, a low pass filter, temperature compensation, self-test, configurable to detect 0g through interrupt pins (INT1 or INT2), and pulse detect for quick motion detection. 0g offset and sensitivity are factory set and require no external devices.
The 0g offset can be customer calibrated using assigned 0g registers and g-Select which allows for command selection for 3 acceleration ranges (2g/4g/8g). The MMA7455L includes a Standby Mode that makes it ideal for handheld battery powered electronics.
Features
• Digital Output (I2C/SPI)
• 3mm x 5mm x 1mm LGA-14 Package
• Self-Test for Z-Axis
• Low Voltage Operation: 2.4 V – 3.6 V
• User Assigned Registers for Offset Calibration
• Programmable Threshold Interrupt Output
• Level Detection for Motion Recognition (Shock, Vibration, Freefall)
• Pulse Detection for Single or Double Pulse Recognition
• Sensitivity (64 LSB/g @ 2g and @ 8g in 10-Bit Mode)
• Selectable Sensitivity (±2g, ±4g, ±8g) for 8-bit Mode
here is a typical module which you can buy
Connection and Layout
- GND – To Wemos GND
- VCC – To Wemos 3V3
- SCL – To Wemos D2
- SDA – To Wemos D1
Code
You will need a copy of the MMA_7455 library to make your life easier. Download and copy to your Arduino -> Libraries folder
[codesyntax lang=”cpp”]
#include <Wire.h> //Include the Wire library #include <MMA_7455.h> //Include the MMA_7455 library MMA_7455 mySensor = MMA_7455(); char xVal, yVal, zVal; void setup() { Serial.begin(9600); delay(500); Serial.println("MMA7455 Accelerometer Test."); mySensor.initSensitivity(2); } void loop() { xVal = mySensor.readAxis('x'); //Read the 'x' Axis yVal = mySensor.readAxis('y'); //Read the 'y' Axis zVal = mySensor.readAxis('z'); //Read the 'z' Axis Serial.print("X = "); Serial.print(xVal, DEC); Serial.print(" Y = "); Serial.print(yVal, DEC); Serial.print(" Z = "); Serial.println(zVal, DEC); delay(1000); }
[/codesyntax]
Testing
Open the serial monitor and move the module about
X = 193 Y = 227 Z = 240
X = 226 Y = 222 Z = 9
X = 0 Y = 207 Z = 54
X = 246 Y = 154 Z = 31
X = 185 Y = 246 Z = 49
X = 175 Y = 252 Z = 31
X = 179 Y = 229 Z = 3
X = 190 Y = 220 Z = 249
Links
MMA7455 Accelerometer Sensor Module AVR ARM MCU