WSM is a model railroad car which measures speed of a train and transmits it via Bluetooth. This repository contains schematics & PCBs layout for all the PCBs used in the car.

The whole car is designed to be supplied by any 3.7V LiPo battery. PCB design allows you to charge the battery via USB, so no disconnecting of the battery nor external changer is required. The measurement is based on an opto-sensor capturing a perforated wheel connected to an axis of a wheel of the car. The speed-data are transmitted via HC-05 bluetooth module to any device supporting SPP bluetooth profile.

This solution consists of a main board (main-board.{brd,sch}) and board for connecting the optosensor (opto-con.{brd,sch}). Main board contains all the logic, optosensor connector board contains no logic, it serves only for mechanical purposes. Optosensor connector board is not required.

• Speed-measuring based on opto-sensor.
• Size 50×18 mm.
• Transmits data via bluetooth.
• No external power supply is required (no current from tracks).
• Runs on battery, can measure up to 8 hours based on chosen battery.
• Integrated charging circuit.
• Charging from micro-USB connector.
• ON/OFF switch.
• Measuring of a battery level & undervoltage protection.

• Firmware to the main CPU.
• Software to PC.

This PCB was designed in Eagle 9.

This boards was tested with GP1S23 opto sensor. This sensor in commonly available at KY-010 Arduino module.

This TeX file allows you to merge top and bottom place layouts into a single document.

• Jan Horacek ([email protected])

• This project is inspired by the measure car designed by Petr Travnik.
• The ON-OFF switch part is inspired by the RB3201 project of RoboticsBrno .
• Many thanks to Michal Petrilak for help with development of this project.

This project is released under the Creative Commons Attribution-ShareAlike 4.0 license.