EDrTech's PMG001 Module Unlocks Precise Power Control and Monitoring for Battery-Powered Devices
ATtiny-based power control module monitors four voltages with high precision, current of a single-cell LiPo, and has protections built in.
After years of searching for a flexible power management system for projects, Erik Rudec of Croatia-based EDrTech decided to design one. The PMG001 is an ATtiny-based power management module for a single-cell LiPo battery. It controls the battery output to the load, monitors voltage levels, measures current consumption, and provides GPIO to manage power programmatically. The castellated edges make it simple to integrate into a project.
EDrTech's PMG001 power management module is a building block that flexibly monitors and manages power from a single-cell LiPo battery. It can monitor four voltage rails with high precision, manage brownout detection (low battery voltage), measure temperature with precision, and accept up to 2 amp charging at 5 volts, giving you the flexibility to adapt it to your specific project needs.
The 22.225 by 16.51-millimeter circuit board has 16 castellated pins along its long sides and packs several highly functional ICs. A Microchip ATtiny1616 microcontroller (MCU) provides overall power management. The default firmware communicates with a host computer via UART to display the state of sensors. Alternatively, you can write custom firmware using the Arduino IDE and megaTinyCore board support package.
PMG001 has a Li-Ion charging circuit that can supply up to 2 amps. However, it only supports a 5 volt input for charging. Like all IOs, the battery connects through the castellated pins.
A four-channel Texas Instruments ADS1015 ADC monitors four voltage rails up to 3.3 volts with 12-bit precision. EDrTech says the PMG001 can monitor higher voltages with external circuits like a voltage divider. Additional ADC channels are also available on the MCU to monitor other voltages.
The MCU controls a discrete MOSFET to control whether the battery connects to PMG001's BAT_OUT pin. The MCU controls this output MOSFET. It can enable the MOSFET with pre-programmed logic or an external pushbutton/switch.
Several monitor ICs add protective capabilities to the PMG001. For example, an INA219 digital power monitor IC measures the battery's output current with a current sense resistor. A Diodes APX803S provides brownout detection and protection when the battery's voltage drops below a programmed limit. This supervisor also inhibits power to the load since holding the MCU in RESET disables the output MOSFET.
EDrTech also offers a demo kit that turns the PMG001 into a full ATtiny1616 development board. The kit includes a CH340 USB to Serial IC to act as a UPDI programmer/debugger and to provide serial communication through a USB Type-C connector. This board has a JST-style connector for adding a LiPo battery and two push buttons. One button acts as the ON/OFF button, and the other is user-programmable.
The well-written datasheet suggests that EDrTech may offer it as a product in the future. For now, you can find the open source schematic (PDF) and PCB (Gerbers) in the PMG001 GitHub repository.