LeadMe - Electrical Design

LeadMe's internals consist of a set of small circuit boards; a control board, a LiPo charging board, a motor driver board, and a Bluetooth communication board. The control board consists of an ATmega microcontroller, which uses the Bluetooth board to take in commands from the user's smartphone, and outputs control signals to the motor driver board, which actuates the vibrating motors on the anklet. Power for this system is provided by a Lithium Polymer battery, which is charged and discharged safely by the LiPo charging board.

Design

LeadMe's internal electronics consist of four small circuit boards, each serving a distinct purpose. The boards are then cast directly into the silicone casing of the device.

Control Board

The control board houses an ATMega328, the brains of the anklet. This board takes in commands via a serial line to the Bluetooth board and issues orders to the motor controllers via PWM. Check out the firmware on Github.

Motor Board

The motor board takes PWM signals from the control board and amplifies them with a FET to run the five motors in the anklet.

Power Board

The power board interfaces with a Lithium Polymer battery, providing a USB port to power a LiPo charging IC and regulating power draw from the battery when the anklet is running.

Bluetooth Board

The Bluetooth board handles communication with the phone, allowing commands to be sent across a serial line to the anklet.

Components

Some of the major electronics components are listed here; see the schematics above for a full overview of components.

  • ATMega 328
  • Bluetooth module
  • Five coin-type vibrating motors
  • 240 mAh lithium polymer battery

For the firmware source code, visit our GitHub repository.

For technical details, click here.