Circuit Documentation

Summary

The circuit in question is designed to interface a SparkFun Pro Micro microcontroller with a BMI160 6DOF sensor and two 24LC512 EEPROM chips. It is powered by a Polymer Lithium Ion Battery with a capacity of 850mAh. The Pro Micro is responsible for processing data from the BMI160 sensor and communicating with the EEPROM chips via I2C protocol. The battery provides the necessary power to the microcontroller and other components. The circuit is likely intended for applications requiring motion tracking and data storage capabilities.

Component List

SparkFun Pro Micro

• Microcontroller board based on the ATmega32U4
• Operates at 5V/16MHz
• Equipped with 18 digital I/O pins and 12 analog inputs

24LC512 EEPROM (x2)

• 512Kbit Electrically Erasable PROM
• I2C interface
• 64-byte page write buffer

BMI160 Accelerometer Gyro - 6DOF sensor

• Inertial Measurement Unit (IMU) with a 3-axis accelerometer and a 3-axis gyroscope
• I2C/SPI interface
• Interrupt pins for motion detection

Polymer Lithium Ion Battery - 850mAh

• Rechargeable battery
• Provides power to the circuit

Wiring Details

SparkFun Pro Micro

• RAW connected to the positive terminal of the Polymer Lithium Ion Battery
• GND connected to the ground plane of the circuit
• D2 (SDA) and D3 (SCL) connected to the I2C bus for communication with EEPROMs and BMI160 sensor
• D7 connected to the INT1 pin of the BMI160 sensor for interrupt-driven events

24LC512 EEPROM

• A0, A1, A2 connected to the ground plane for address selection (assuming address grounding)
• Vss connected to the ground plane
• Vcc connected to the positive voltage rail
• WP connected to the ground plane (write protection disabled)
• SCL and SDA connected to the I2C bus

BMI160 Accelerometer Gyro - 6DOF sensor

• GND connected to the ground plane
• VIN connected to the positive voltage rail
• SDA and SCL connected to the I2C bus
• INT1 connected to D7 on the SparkFun Pro Micro for interrupts

Polymer Lithium Ion Battery - 850mAh

• VCC connected to the RAW pin of the SparkFun Pro Micro
• GND connected to the ground plane of the circuit

Documented Code

#include <BMI160Gen.h>
// Requires https://github.com/hanyazou/BMI160-Arduino

const int bmi160_i2c_addr = 0x69;
const int bmi160_interrupt_pin = 7;
bool running = false;
int RXLED = 17;

unsigned long miPoll, miPrint = 1000;

int16_t absx, absy, absz;
int ax, ay, az;
//int gx, gy, gz;

#define runEvery(t) for (static typeof(t) _lasttime; \
                         (typeof(t))((typeof(t))millis() - _lasttime) > (t); \
                         _lasttime += (t))

void bmi160_intr(void)
{
  running = !running;
  if(running) {
    digitalWrite(RXLED, LOW); // RX LED on!
    TXLED1; //TX LED ON Macro
  } else {
    digitalWrite(RXLED, HIGH); // RX LED on!
    TXLED0;
  }
}

void setup() {

  Serial.begin(9600);
  while (!Serial);

  // initialize device
  BMI160.begin(BMI160GenClass::I2C_MODE, bmi160_i2c_addr, bmi160_interrupt_pin);
  BMI160.attachInterrupt(bmi160_intr);
  BMI160.setIntDoubleTapEnabled(true);
 
  BMI160.autoCalibrateGyroOffset();
  BMI160.autoCalibrateXAccelOffset(0);
  BMI160.autoCalibrateYAccelOffset(0);
  BMI160.autoCalibrateZAccelOffset(1);
  BMI160.setGyroOffsetEnabled(true);
  BMI160.setAccelOffsetEnabled(true);

  miPoll = 1000/BMI160.getAccelerometerRate();

  digitalWrite(RXLED, HIGH);
  TXLED0;
}

void loop() {
  if (running) {
    runEvery(miPoll) {
      BMI160.readGyro(ax, ay, az);
      absx = absx + ax;
      absy = absy + ay;
      absz = absz + az;
    } 
    runEvery(miPrint) {
      Serial.print(absx); Serial.print("\t");
      Serial.print(absy); Serial.print("\t");
      Serial.println(absz);
    }
  }
}

This code is designed to run on the SparkFun Pro Micro microcontroller. It initializes the BMI160 sensor, sets up interrupt handling for motion detection, and periodically reads gyroscopic data, outputting the accumulated values over the serial connection. The LED indicators are used to signal the running state of the device.