PCB DESIGN FOR A BIKE COMPUTER DIY - QBIKO

This PCB was designed to run a BIke computer based on ESP32 and BLE.

All the information about speed, cadence, distance, time of the travel, and other is transmitted to an APP on your smart Phone

Sensors are reed switches and is the cheapest way to obtain all the infrmation you can upload to STRAVA for tracking your training and performance

1.STORY

This design was a challenge to replicate a commercial bike computer in a disruptive and a cheaper way. From the sensors to the APP it was developed to integrate available software and hardware componentes and plattforms.

2.DESIGN

The tool to design was EASYEDA trademark, it was as simple as possible using a esp32wroom whit BLE running code uploaded from Arduino IDLE.

Cadence and speed sensors are wiring directly to the PCB, also one battery and one charging port module.

The operation is : 1 one running mode and 2. one battery charge mode, this is indicated by two leds and configured through two switches

Also was added one OLED screen to monitoring if the bike computer are processing signal from the sensors wired.Other information could be reported to the OLED screen, but for me is enough because I have a lot of data in the Smart Phone, so I need to linked to record my bike training sessions.

In the picture above we can see the charge Battery, the LIPO module operating and the Charging indicated by one LED on. In this operation mode the Bike computer is not working or running only charging the battery (charging timelapse-1-2 hours).

We can connect SPD and CAD sensors and also configure operation mode with the switches. The components are standard, cheap and available in the electronics stores.Tools are soldering and others. Please be carefull because the design and PCB use the big one esp32 module with 38 pins.

Future improvements could be using smd components and smaller esp32 module- the size could be 50% of this design area.Other imporvements are:

a. OUTDOOR water resisitant case-IP65 at least

b. Add one battery to get more power autonomy- 8 hours of autonomy with lipo 1000mAhr batteries

c.Add other wired sensor for power on bike pedals or weather conditions or tearring grade(from a gyroscope sensor)

d. SMD components

e.Add a hidden GPS component to track the bike in case of assault or theft

In this video we can check the 3D view of the PCB and the final result with all the componens mounted.

PCB Design- 3D view

The device work properly and is subject to improvements, but for the porpuse is fine and cheap.

Now you can focus your bike training knowing real time speed, real time cadence, real time heart rate, and upload all your data to apps for bikers as STRAVA. I am sure you will be happy with the QBIKO bike computer.

PCB unboxing, components mounting, operational tests

3.TEST

Mounted in the bike and linked with the app IPBIKE, the bike computer works perfect.

The charging mode also work properly.

We have not found mistakes in components or PCB connections for the two layers, also any mistake or short circuit in the soldering process.

We have tested outdoor however in sunny days because the case is cheap and wood material fabricated so if you are exposed to rain please take care of your device.Outdoor use in raining season need at least IP65 enclosure.