Circuit Documentation

Summary

The circuit described in the provided information is a solar power management system with monitoring capabilities. It includes a solar panel for energy harvesting, a charge controller for managing the power flow to and from batteries, and a monitoring system using an INA3221 sensor to measure voltage and current across different points in the circuit. The system also includes a microcontroller (Xiao esp32c3) for control and communication purposes, and an AHT21 sensor for environmental data collection. The power storage is handled by a 12V AGM battery and a 3.7V 3700mAh battery, with a Waveshare Solar Manager for additional power management and a battery holder for 18650 batteries.

Component List

Power Sources

• 12V AGM Battery: A lead-acid battery used as a primary power source.
• Solar Panel: Converts sunlight into electrical energy to charge the batteries.

Power Management

• MPPT 12V Charge Controller: Maximizes the power output from the solar panel and charges the 12V battery.
• Waveshare Solar Manager (D): Manages the power from the solar panel and provides a Type-C 5V output.

Monitoring

• INA3221-Updated-3_Ind_Loads: A triple-channel shunt and bus voltage monitor with I2C interface for voltage and current measurement.

Sensors

• AHT21: A temperature and humidity sensor for environmental monitoring.

Microcontroller

• Xiao esp32c3-front: A microcontroller with Wi-Fi capabilities for control and data communication.

Storage

• 3.7V 3700mAh Battery: A lithium-ion battery used as a secondary power source.
• 18650 x 3 Battery Holder: Holds three 18650 batteries for additional power storage.

Miscellaneous

• Comments: Placeholder components without electrical function, used for annotations in the circuit design.

Wiring Details

12V AGM Battery

• Positive terminal connected to VIN2- of INA3221.
• Negative terminal connected to:
  • Negative terminal of MPPT 12V Charge Controller.
  • GND of INA3221.

Solar Panel

• Positive terminal connected to:
  • Positive terminal of MPPT 12V Charge Controller.
  • VIN3+ of INA3221.
• Negative terminal connected to:
  • Negative terminal of MPPT 12V Charge Controller.
  • IN- Solar 6V~24V of Waveshare Solar Manager (D).

MPPT 12V Charge Controller

• Positive terminal connected to VIN2+ of INA3221.
• Negative terminal shared with 12V AGM Battery and Solar Panel.

INA3221-Updated-3_Ind_Loads

• VIN1-, VIN2-, and VIN3- connected to respective negative terminals of batteries and solar panel.
• VIN1+, VIN2+, and VIN3+ connected to respective positive terminals of batteries and solar panel.
• VS connected to Vin+ 2~5V Red of AHT21.
• SCL connected to SCL Clock Yellow of AHT21 and GPIO7/SCL/D5 of Xiao esp32c3.
• SDA connected to SDA Data Blue of AHT21 and GPIO6/SDA/D4 of Xiao esp32c3.
• GND connected to GND Black of AHT21 and GND of Xiao esp32c3.

3.7V 3700mAh Battery

• Positive terminal connected to VIN1- of INA3221.
• Negative terminal connected to:
  • GND of INA3221.
  • 3.7V BATT- of Xiao esp32c3.

AHT21

• Vin+ 2~5V Red connected to VS of INA3221 and 3V3 of Xiao esp32c3.
• GND Black connected to GND of INA3221 and GND of Xiao esp32c3.
• SCL Clock Yellow connected to SCL of INA3221 and GPIO7/SCL/D5 of Xiao esp32c3.
• SDA Data Blue connected to SDA of INA3221 and GPIO6/SDA/D4 of Xiao esp32c3.

Waveshare Solar Manager (D)

• IN+ Solar 6V~24V connected to VIN3- of INA3221.
• Type-C 5V connected to Type C of Xiao esp32c3.
• 3.7V BATT PH2.0 4P connected to PH2.0 4P connector of 18650 x 3 Battery Holder.

Xiao esp32c3-front

• 3.7V BATT+ connected to VIN1+ of INA3221.
• 3.7V BATT- connected to GND of INA3221 and negative terminal of 3.7V 3700mAh Battery.
• 3V3 connected to Vin+ 2~5V Red of AHT21.
• GND connected to GND Black of AHT21.
• GPIO7/SCL/D5 connected to SCL Clock Yellow of AHT21 and SCL of INA3221.
• GPIO6/SDA/D4 connected to SDA Data Blue of AHT21 and SDA of INA3221.
• Type C connected to Type-C 5V of Waveshare Solar Manager (D).

18650 x 3 Battery Holder

• PH2.0 4P connector connected to 3.7V BATT PH2.0 4P of Waveshare Solar Manager (D).

Documented Code

No code has been provided for the microcontroller in this circuit. If code is available, it should be documented here with explanations for each function and routine, including setup and loop functions, interrupt service routines, and any communication protocol implementations.