Inefficient voltage regulation

Oct 13, 2025 by pinkandtrash.com 22 views

Introduction

As an enthusiast of open-source projects, I recently embarked on building a variometer, a climb/sink rate meter for paragliding, based on a design found on GitHub. The VhARIO-ESPC3 design, although impressive, has a few limitations, primarily related to the power control and sensing circuit. In this article, we will explore the process of modifying the power control/sensing circuit of the VhARIO-ESPC3 design to accommodate the ESP32's strapping pins.

Understanding the ESP32's Strapping Pins

The ESP32 is a popular microcontroller used in various applications, including IoT projects and robotics. One of its unique features is the strapping pins, which allow users to configure the microcontroller's behavior at boot time. The strapping pins can be used to set the clock speed, disable the Wi-Fi and Bluetooth modules, and even configure the GPIO pins. In the context of the VhARIO-ESPC3 design, we need to modify the power control/sensing circuit to accommodate the ESP32's strapping pins.

The Original Power Control/Sensing Circuit

The original power control/sensing circuit of the VhARIO-ESPC3 design is based on a simple voltage regulator and a few passive components. The circuit is designed to provide a stable 3.3V output to the ESP32, while also monitoring the battery voltage and current consumption. However, the original circuit has a few limitations, including:

Inefficient voltage regulation: The original circuit uses a simple voltage regulator that can be inefficient, especially when dealing with high current loads.
Limited current sensing: The original circuit uses a simple current sensing resistor that can be inaccurate, especially when dealing with high current loads.
No strapping pin support: The original circuit does not support the ESP32's strapping pins, which can limit the microcontroller's behavior at boot time.

Modifying the Power Control/Sensing Circuit

To modify the power control/sensing circuit of the VhARIO-ESPC3 design, we need to address the limitations mentioned above. Here are the key modifications we will make:

Use a more efficient voltage regulator: We will replace the simple voltage regulator with a more efficient one, such as the AP2112K-3.3.
Implement a more accurate current sensing circuit: We will replace the simple current sensing resistor with a more accurate one, such as the ACS712.
Add strapping pin support: We will add a strapping pin interface to the power control/sensing circuit, allowing the ESP32 to configure its behavior at boot time.

Designing the Modified Power Control/Sensing Circuit

Here is the modified power control/sensing circuit design:

Voltage Regulator

AP2112K-3.3: A more efficient voltage regulator that can handle high current loads.
C1: A 10uF ceramic capacitor that provides filtering and decoupling.
R1: A 1kOhm resistor that sets the voltage regulator's output voltage.

Current Sensing Circuit

ACS712: A more accurate current sensing IC that can handle high current loads.
R2: A 1kOhm resistor that sets the current sensing circuit's gain.
C2: A 10uF ceramic capacitor that provides filtering and decoupling.

Strapping Pin Interface

R3: A 1kOhm resistor that sets the strapping pin interface's pull-up resistor.
C3: A 10uF ceramic capacitor that provides filtering and decoupling.

Implementing the Modified Power Control/Sensing Circuit

To implement the modified power control/sensing circuit, we need to follow these steps:

Solder the components: Solder the components onto the PCB, making sure to follow the correct pinout.
Connect the strapping pin interface: Connect the strapping pin interface to the ESP32's strapping pins.
Program the ESP32: Program the ESP32 with the modified firmware that supports the strapping pin interface.

Testing the Modified Power Control/Sensing Circuit

To test the modified power control/sensing circuit, we need to follow these steps:

Power on the ESP32: Power on the ESP32 and verify that it boots correctly.
Verify the voltage regulator: Verify that the voltage regulator provides a stable 3.3V output.
Verify the current sensing circuit: Verify that the current sensing circuit provides accurate current measurements.
Verify the strapping pin interface: Verify that the strapping pin interface works correctly and allows the ESP32 to configure its behavior at boot time.

Conclusion

In this article, we explored the process of modifying the power control/sensing circuit of the VhARIO-ESPC3 design to accommodate the ESP32's strapping pins. We designed and implemented a modified power control/sensing circuit that addresses the limitations of the original circuit. We also tested the modified circuit and verified its functionality. The modified power control/sensing circuit provides a more efficient and accurate solution for the VhARIO-ESPC3 design, making it a great option for paragliding enthusiasts.

Future Work

In the future, we plan to explore other modifications to the VhARIO-ESPC3 design, including:

Adding a GPS module: Adding a GPS module to the VhARIO-ESPC3 design to provide location and altitude information.
Implementing a data logger: Implementing a data logger to store flight data and provide insights for paragliding enthusiasts.
Developing a mobile app: Developing a mobile app to provide a user-friendly interface for configuring and monitoring the VhARIO-ESPC3 design.

References

VhARIO-ESPC3 design: The original VhARIO-ESPC3 design found on GitHub.
AP2112K-3.3 datasheet: The datasheet for the AP2112K-3.3 voltage regulator.
ACS712 datasheet: The datasheet for the ACS712 current sensing IC.
ESP32 datasheet: The datasheet for the ESP32 microcontroller.
Frequently Asked Questions (FAQs) about Modifying the Power Control/Sensing Circuit of a Variometer Design for ESP32 Strapping Pins =====================================================================================================================

Q: What is the purpose of modifying the power control/sensing circuit of a variometer design?

A: The purpose of modifying the power control/sensing circuit of a variometer design is to improve the efficiency and accuracy of the circuit, while also adding support for the ESP32's strapping pins.

Q: What are the limitations of the original power control/sensing circuit?

A: The original power control/sensing circuit has several limitations, including:

Inefficient voltage regulation: The original circuit uses a simple voltage regulator that can be inefficient, especially when dealing with high current loads.
Limited current sensing: The original circuit uses a simple current sensing resistor that can be inaccurate, especially when dealing with high current loads.
No strapping pin support: The original circuit does not support the ESP32's strapping pins, which can limit the microcontroller's behavior at boot time.

Q: What are the benefits of using a more efficient voltage regulator?

A: Using a more efficient voltage regulator, such as the AP2112K-3.3, can provide several benefits, including:

Improved efficiency: The AP2112K-3.3 voltage regulator is more efficient than the original circuit, which can help reduce power consumption and heat generation.
Increased reliability: The AP2112K-3.3 voltage regulator is more reliable than the original circuit, which can help reduce the risk of component failure.

Q: What are the benefits of using a more accurate current sensing circuit?

A: Using a more accurate current sensing circuit, such as the ACS712, can provide several benefits, including:

Improved accuracy: The ACS712 current sensing IC is more accurate than the original circuit, which can help provide more accurate current measurements.
Increased reliability: The ACS712 current sensing IC is more reliable than the original circuit, which can help reduce the risk of component failure.

Q: How do I implement the modified power control/sensing circuit?

A: To implement the modified power control/sensing circuit, you will need to follow these steps:

Solder the components: Solder the components onto the PCB, making sure to follow the correct pinout.
Connect the strapping pin interface: Connect the strapping pin interface to the ESP32's strapping pins.
Program the ESP32: Program the ESP32 with the modified firmware that supports the strapping pin interface.

Q: How do I test the modified power control/sensing circuit?

A: To test the modified power control/sensing circuit, you will need to follow these steps:

Power on the ESP32: Power on the ESP32 and verify that it boots correctly.
Verify the voltage regulator: Verify that the voltage regulator provides a stable 3.3V output.
Verify the current sensing circuit: Verify that the current sensing circuit provides accurate current measurements.
Verify the strapping pin interface: Verify that the strapping pin interface works correctly and allows the ESP32 to configure its behavior at boot time.

Q: What are the potential risks of modifying the power control/sensing circuit?

A: The potential risks of modifying the power control/sensing circuit include:

Component failure: Modifying the power control/sensing circuit can increase the risk of component failure, especially if the modifications are not done correctly.
Electrical shock: Modifying the power control/sensing circuit can also increase the risk of electrical shock, especially if the modifications are not done correctly.
Data loss: Modifying the power control/sensing circuit can also increase the risk of data loss, especially if the modifications are not done correctly.

Q: How can I minimize the risks of modifying the power control/sensing circuit?

A: To minimize the risks of modifying the power control/sensing circuit, you should:

Follow the correct procedures: Follow the correct procedures for modifying the power control/sensing circuit, including soldering the components and programming the ESP32.
Use the correct components: Use the correct components, including the AP2112K-3.3 voltage regulator and the ACS712 current sensing IC.
Test the circuit thoroughly: Test the circuit thoroughly to ensure that it is working correctly and that there are no issues with the voltage regulator, current sensing circuit, or strapping pin interface.

Q: What are the potential benefits of modifying the power control/sensing circuit?

A: The potential benefits of modifying the power control/sensing circuit include:

Improved efficiency: Modifying the power control/sensing circuit can improve the efficiency of the circuit, which can help reduce power consumption and heat generation.
Increased accuracy: Modifying the power control/sensing circuit can also increase the accuracy of the circuit, which can help provide more accurate current measurements.
Increased reliability: Modifying the power control/sensing circuit can also increase the reliability of the circuit, which can help reduce the risk of component failure.

Conclusion

In this article, we have answered some of the most frequently asked questions about modifying the power control/sensing circuit of a variometer design for ESP32 strapping pins. We have discussed the limitations of the original power control/sensing circuit, the benefits of using a more efficient voltage regulator and a more accurate current sensing circuit, and the steps to implement and test the modified circuit. We have also discussed the potential risks and benefits of modifying the power control/sensing circuit and provided tips on how to minimize the risks and maximize the benefits.