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Circuit schematic

Sensor node wiring

ESP32 DevKit V1 with the MPU6050, DS3231 RTC and NEO-6M GPS. The I²C devices share one bus with 4.7 kΩ pull-ups.

3.3 V power GND SDA · GPIO 21 SCL · GPIO 22 GPS TX → RX2 · GPIO 16 TX2 → GPS RX · GPIO 17

Wiring diagram

Swipe sideways to see the whole board, or pinch to zoom. KiCad PDF
ESP32 DevKit V1 · 38-pin CPU 240 MHz 3V3 EN GND D21 SDA D22 SCL D16 RX2 D17 TX2 VIN (5 V) GND 3V3 4k7 R1 4k7 R2 MPU6050 accel · gyro InvenSense MPU-6050 VCC GND SCL SDA AD0 to 3V3 = 0x69 INT DS3231 RTC TCXO · CR2032 CR2032 3.0 V DS3231 VCC GND SCL SDA NEO-6M GPS u-blox · NMEA 0183 u-blox NEO-6M patch antenna VCC GND TX RX PPS IPDS Sensor Node I²C: MPU 0x69 · RTC 0x68 UART2: 9600 baud Pull-ups: 4.7 kΩ SDA, SCL Power: 3.3 V · ~0.6 W active

MPU6050 to ESP32

PinESP32Signal
VCC3V33.3 V power
GNDGNDGround
SCLGPIO 22I²C clock
SDAGPIO 21I²C data
AD03V3Address 0x69
INT–Not connected

DS3231 RTC to ESP32

PinESP32Signal
VCC3V33.3 V power
GNDGNDGround
SCLGPIO 22I²C clock (shared)
SDAGPIO 21I²C data (shared)
BAT–CR2032 backup cell
SQW–Not connected

NEO-6M GPS to ESP32

PinESP32Signal
VCC3V33.3 V power
GNDGNDGround
TXGPIO 16 (RX2)UART data out
RXGPIO 17 (TX2)UART data in
PPS–Not connected

I²C bus and UART

ItemValueNotes
R1 (SDA)4.7 kΩ3.3 V to SDA line
R2 (SCL)4.7 kΩ3.3 V to SCL line
Bus speed100 kHzStandard mode
MPU addr0x69AD0 tied to 3V3
RTC addr0x68Fixed (DS3231)
UART29600baud, GPS serial