DIGIKEY DKSB1002A Evaluation Board 3-axis accelerometer Arduino Uno microcontroller board Acquiring Data from an ADXL335 Accelerometer living with the lab

DKSB1002A is a prototyping board purchased for $20 from Digikey Screw holes for mounting board onto “object of interest” Board is ~ 20mm square ADXL335 3-axis accelerometer chip 3-axis ±3g COM - ground VSS - power (we will provide 5V) X - acceleration in x-direction Y - acceleration in y-direction Z - acceleration in z-direction DKSB1002A Evaluation Board and ADXL335 Accelerometer x y z this small chip is the ADXL335 accelerometer (this is an older model... they are even smaller now) living with the lab 2 the DKSB1002A is a board used to evaluate the accelerometer; if you were putting an accelerometer in a device like a cell phone, you would only use the ADXL335 chip (and maybe some capacitors)

COM - ground VSS - power (we will provide 5V) X - acceleration in x-direction Y - acceleration in y-direction Z - acceleration in z-direction Implementing a 3-axis Accelerometer: Wiring to Arduino living with the lab 3

void setup() { Serial.begin(9600); } void loop() { int xaccel = analogRead(0); int yaccel = analogRead(1); int zaccel = analogRead(2); unsigned long timevar = millis(); Serial.print(timevar); Serial.print(" "); Serial.print(xaccel); Serial.print(" "); Serial.print(yaccel); Serial.print(" "); Serial.println(zaccel); } Programming living with the lab 4 associates a time with each set of accelerations

Calibration x y z living with the lab 5

Angle Measurement x y z 1g (perceived vertical acceleration) axax xx xx +x θ x = asin(a x /g) living with the lab 6

Example Application living with the lab 7 void setup(){Serial.begin(9600); } void loop() { int xaccel = analogRead(0); int freq = 1500+xaccel*2; tone(7,freq); Serial.print(xaccel); Serial.print(" "); Serial.println(freq); } The piezospeaker below outputs a frequency that varies with the acceleration in the x- direction. The equation for computing the frequency is chosen so that the device makes an audible noise that varies when rotating or shaking the device.