Circuit Documentation

Summary

This document provides a detailed overview of a circuit that includes various sensors, microcontrollers, and power management components. The circuit is designed to interface multiple sensors with ESP32 microcontrollers, powered by a LiPo battery through a step-down buck converter. The sensors include a pressure sensor, an ultrasonic sensor, and an inertial measurement unit (IMU). The document includes a component list, wiring details, and the embedded code used in the microcontrollers.

Component List

1. SparkFun Pressure Sensor Breakout - MS5803-14BA

   • Pins: GND, 3.3V, SDA/SDI, SCL/SCLK, SDO, AD/CS, PS
   • Description: Pressure sensor for measuring atmospheric pressure.
   • Purpose in Circuit: To provide pressure data to the ESP32 microcontroller.

2. BNO055

   • Pins: Vin, 3vo, GND, SDA, SCL, RST, PS0, PS1, INT, ADR
   • Description: 9-axis absolute orientation sensor.
   • Purpose in Circuit: To provide orientation data to the ESP32 microcontroller.

3. Lipo Battery

   • Pins: VCC, GND
   • Description: Rechargeable lithium polymer battery.
   • Purpose in Circuit: To provide power to the entire circuit.

4. ESP32

   • Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, VIN, 3V3, D15, D2, D4, RX2, TX2, D5, D18, D19, D21, RX0, TX0, D22, D23, BOOT
   • Description: Wi-Fi and Bluetooth microcontroller.
   • Purpose in Circuit: To control and process data from the sensors.

5. Ultrasonic Sensor

   • Pins: +VCC, Trigger, Echo, GND
   • Description: Sensor for measuring distance using ultrasonic waves.
   • Purpose in Circuit: To provide distance measurements to the ESP32 microcontroller.

6. Step down Buck converter

   • Pins: IN +, IN - GND, OUT +, OUT - GND
   • Description: Voltage regulator to step down the voltage from the LiPo battery.
   • Purpose in Circuit: To provide a stable voltage supply to the components.

Wiring Details

SparkFun Pressure Sensor Breakout - MS5803-14BA

• GND connected to GND of ESP32.
• 3.3V connected to 3V3 of ESP32.
• SDA/SDI connected to D21 of ESP32.
• SCL/SCLK connected to D22 of ESP32.

BNO055

• Vin connected to VIN of ESP32.
• GND connected to GND of ESP32.
• SDA connected to D21 of ESP32.
• SCL connected to D22 of ESP32.

Lipo Battery

• VCC connected to IN + of Step down Buck converter.
• GND connected to IN - GND of Step down Buck converter.

ESP32 (First Instance)

• VIN connected to OUT + of Step down Buck converter.
• GND connected to OUT - GND of Step down Buck converter.
• 3V3 connected to 3.3V of SparkFun Pressure Sensor Breakout - MS5803-14BA.
• D21 connected to SDA/SDI of SparkFun Pressure Sensor Breakout - MS5803-14BA.
• D22 connected to SCL/SCLK of SparkFun Pressure Sensor Breakout - MS5803-14BA.

ESP32 (Second Instance)

• VIN connected to OUT + of Step down Buck converter.
• GND connected to OUT - GND of Step down Buck converter.
• D34 connected to Echo of Ultrasonic Sensor.
• D35 connected to Trigger of Ultrasonic Sensor.

ESP32 (Third Instance)

• VIN connected to OUT + of Step down Buck converter.
• GND connected to OUT - GND of Step down Buck converter.
• D21 connected to SDA of BNO055.
• D22 connected to SCL of BNO055.

Ultrasonic Sensor

• +VCC connected to VIN of ESP32.
• GND connected to GND of ESP32.
• Echo connected to D34 of ESP32.
• Trigger connected to D35 of ESP32.

Step down Buck converter

• IN + connected to VCC of Lipo Battery.
• IN - GND connected to GND of Lipo Battery.
• OUT + connected to VIN of ESP32.
• OUT - GND connected to GND of ESP32.

Documented Code

ESP32 (First Instance)

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

ESP32 (First Instance) Documentation

This concludes the documentation for the circuit. Each component is described along with its wiring details, and the embedded code for the microcontroller is provided.