Build a Power Supply Monitoring and Control System

Using the ESP32 MCU Switching power supplies are a key piece of gear for many projects. But cost-effective units benefit from some kind of outside means of stepping output voltage up or down. To address that issue, Anuj built a power supply monitoring and control system using an ESP32-based development board. Topics Discussed How to build a power supply monitoring and control system using an ESP32-based dev boardHow to implement the hardware designHow the prototype operatesHow to develop the softwareHow to do the firmware and the testing Tech Used Espressif Systems’ ESP32-D0WDQ6 MCUTTGO-T-Display ESP32 Wi-Fi/Bluetooth module dev board from LILYGO ESP-IDF (Espressif’s IoT Development Framework)Texas instruments’ (TI’s) voltage regulator LM338TTI INA219B power monitor sensor in a breakout boardSitronix ST7789V driverL7805CV fixed voltage regulator from STMicroelectronics (ST)  Power supplies are essential for various electrical or electronic experiments. Switching mode power supplies (SMPS) act as a very good source of DC electrical power with high efficiency for various applications. The regular cost-effective ones have a minimalist design and constant output voltage. Such units often need to have their output voltage stepped down or stepped up depending on the devices that the supply is powering. I bought one such SMPS but wanted more control over the power output—like voltage control and configurable over current protection—while also being able to monitor the state of the output power. With all that in mind, I built a power monitoring and control system with a TTGO-T-Display ESP32 Wi-Fi/Bluetooth module development board from LILYGO [1]. The system has an onboard display and an Espressif Systems’ ESP32-D0WDQ6 microcontroller (MCU) chip [2] as its processing unit. The block diagram of the system is shown in Figure 1. Figure 1 System block diagram The prototype uses ESP-IDF (Espressif’s IoT Development Framewor