Add runtime motor speed settings to web interface Summary

[FIWAtec]

✅ GitHub Issue: Add runtime motor speed settings to web interface
Summary

I added a feature to set the motor speeds (printSpeed and moveSpeed) at runtime from the web interface.
This makes it possible to fine-tune drawing speed without recompiling the firmware.

The feature consists of:

new input fields in index.html

a new request handler /setSpeeds in main.cpp

two global variables: printSpeedSteps and moveSpeedSteps

a new function Movement::setSpeeds()

updating both AccelStepper motors dynamically

✅ Changes in detail

1. Global speed variables

Added to movement.cpp:

int printSpeedSteps = 1200; // default
int moveSpeedSteps = 2000; // default

These values can now be modified at runtime instead of being fixed constants.

2. New function in Movement class

Added to movement.h:

void setSpeeds(int newPrintSpeed, int newMoveSpeed);

Implementation in movement.cpp:

void Movement::setSpeeds(int newPrintSpeed, int newMoveSpeed) {
printSpeedSteps = newPrintSpeed;
moveSpeedSteps = newMoveSpeed;

leftMotor->setMaxSpeed(moveSpeedSteps);
rightMotor->setMaxSpeed(moveSpeedSteps);

}

This allows both motors to update their speed instantly.

3. New REST endpoint in main.cpp

Added:

server.on("/setSpeeds", HTTP_POST, [](AsyncWebServerRequest *request)
{
if (!request->hasParam("printSpeed", true) ||
!request->hasParam("moveSpeed", true)) {
request->send(400, "text/plain", "Missing parameters");
return;
}

int printSpeed = request->getParam("printSpeed", true)->value().toInt();
int moveSpeed  = request->getParam("moveSpeed", true)->value().toInt();

if (printSpeed <= 0 || moveSpeed <= 0) {
    request->send(400, "text/plain", "Invalid values");
    return;
}

movement->setSpeeds(printSpeed, moveSpeed);
request->send(200, "text/plain", "OK");

});

This receives the speed values from the browser and updates the Movement module.

4. Web UI: two new input fields + button

Added to index.html (Distance slide):

Print speed (steps/s)

Move speed (steps/s)

Set speeds

5. JavaScript handler in main.js

Added:

$("#setSpeeds").click(function () {
const printSpeed = parseInt($("#printSpeedInput").val());
const moveSpeed = parseInt($("#moveSpeedInput").val());

if (isNaN(printSpeed) || isNaN(moveSpeed)) {
    alert("Bitte Zahlen für beide Geschwindigkeiten eingeben.");
    return;
}

$.post("/setSpeeds", { printSpeed: printSpeed, moveSpeed: moveSpeed })
    .done(() => alert("Speeds updated"))
    .fail(() => alert("Setting speeds failed"));

});

This sends the values directly to the ESP32.

✅ Benefit

No flashing required to adjust motor speed

Users can tune drawing speed depending on:

wall surface

marker friction

belt tension

detail level of SVG

Makes the plotter more flexible and user-friendly.

[CCERocks]

This is awesome! Thanks for the tweak bro!

[FIWAtec]

Thanks! Glad it’s useful.

Just a heads-up though: we’re currently retrofitting mechanical brakes / load-holding on the motors (plus some tension + friction tweaks), so the “best” speed values will likely shift once that hardware is in place. Runtime speed control is actually perfect for dialing it in during that phase without reflashing every five minutes.

Once the brake setup is finalized, we’ll share recommended speed ranges (print vs. move) for typical wall surfaces / marker friction.