Published November 26, 2018

MEGR 3171 MTB Dropper Post Sensor

An automatic suspension fork compression changing device that responds to dropper post movement.

IntermediateFull instructions provided637

Things used in this project

Hardware components

Particle Photon

Servo Module (Generic)

Proximity Sensor

4xAA battery holder

Solderless Breadboard Half Size

Male/Male Jumper Wires

Software apps and online services

Particle Pi

Story

Background

The mountain biking community has been flooded with innovation over the past few years. Companies are constantly trying to make your ride faster, longer and more entertaining. The invention of the dropper seat post and adjustable suspension for mountain bikes are two separate aspects of the bike that has changed the way people ride their bikes. This project ties both innovations together using two Particle Photons.

How It Works

When descending down a trail on a mountain bike, an individual wants to lower their center of gravity which is done through lowering the seat by depressing a lever on the handle bars. The rider will also want the suspension of their bike to have as much travel as possible to soak up bumps which is accomplished by turning a knob on the front fork. The opposite is true for climbing up a trail. A rider wants the seat in a raised position and fork to have less travel to conserve energy. By tying these two motions together, we have created one streamlined process.

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On the rear of the bike, we have mounted one of the Particle Photons and a proximity sensor to detect the position of the seat.

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On the front of the bike, we have mounted the other Particle Photon which is connected to the servo motor attached to the fork adjustment knob.

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Once the proximity sensor senses the lowered position of the seat, it sends a signal to the servo motor which turns the fork adjustment to "descend" mode. When the seat is then in the raised position, another signal is sent to turn the fork adjustment into "climb" mode.

A short explanation and demonstration of this project in action can be seen in the video below.

Other Information

Here is a link to a Google Spreadsheet with a real time data display of the seat post position. This was accomplished by creating an IFTTT applet that wrote to a spreadsheet when "seatpost" was published by one of the photons. The graph shown is the graph after testing the setup.

https://docs.google.com/spreadsheets/d/1OfWtOKV_UtxsRZtXzryfi_QgGiSa5zywqZqoi6w8-gk/edit?usp=sharing

Seat position counts graph

This project has room for improvement in the cycling industry. The invention of the electric assist bike has already brought the world of circuits, batteries and electricity to the mountain biking world. With a little more development and the use of existing technology, this idea could be internalized into the respective parts, making the system more durable and reliable.

Code

Servo myservo; //creates the servo to be used
void setup() {
Particle.publish("light", "devices talking"); //publishes to the cloud to confirm the photons are communicating
Particle.subscribe("seatpost", myHandler); //subscribes to the event seatpost published by the other photon
}


void myHandler(const char *event, const char *data)
{

 if (strcmp(data,"SeatUp")==0) { //tells the servo to turn to a specific angle if  the photon reads the seat up function from the cloud
myservo.attach(D0);
myservo.write(180);
delay(2000);
myservo.detach();

}
else if (strcmp(data,"SeatDown")==0) { //tells the servo to turn to a specific angle if the photon reads the seat up function from the cloud
myservo.attach(D0);
myservo.write(110);
delay(2000);
myservo.detach();
}
 
}

int sensor = D4;  //sets up the sensor as connected to D4

void myHandler(const char *event, const char *data)
{}
void setup() {
pinMode(sensor,INPUT);
Particle.subscribe("light", myHandler); //subscribes to the cloud event published by the other photon to confirm                                                   connection
}
void loop() {

{
if (digitalRead(sensor)==HIGH){ //Publishes the seat up event if the proximity sensor gets a reading that triggers it
    
    Particle.publish("seatpost","SeatUp",PUBLIC);
    delay(2000);
    System.sleep(40); //onlyl publishes to the cloud once per loop
   
}
else if (digitalRead(sensor)==LOW){ //publishes the seat down event if the proximity sensor does not read the seat as being close
    Particle.publish("seatpost","SeatDown",PUBLIC);
    delay(2000);
    System.sleep(40); //only publishes to the cloud once per loop
}}}

Credits

George Stewart

1 project • 1 follower

Andrew Blankenship

1 project • 0 followers

MEGR 3171 MTB Dropper Post Sensor