User input

Elements the user operates on the phone. Each writes into an input channel (1…16) on the board, chosen with setChannel(k) or the constructor's last argument. The board reads a channel with PhyphoxBLE::read(...), PhyphoxBLE::readChannel(k) or PhyphoxBLE::changed(k), or attaches a callback: element.onChange(fn), button.onPress(fn), PhyphoxBLE::onChange(k, fn). Callbacks are plain functions (a captureless lambda works):

float blinkInterval = 100;
bool ledOn = true;
 
PhyphoxBleExperiment::Slider interval("Interval", 50, 1000, 50, /*channel*/ 1);
interval.setUnit("ms"); interval.setDefault(100);
interval.onChange([](float v) { blinkInterval = v; });
 
PhyphoxBleExperiment::Toggle led("LED", 2);
led.setDefault(1);
led.onChange([](float v) { ledOn = v > 0.5f; });
 
PhyphoxBleExperiment::Dropdown mode("Mode", 3);
mode.addOption("Always on", 1); mode.addOption("Blink", 2); mode.addOption("Flash", 3);
 
PhyphoxBleExperiment::Button zero("Set zero", 4);
zero.onPress([]() { offset = lastReading; });

Two elements may share a channel — an edit field and a slider for the same value, say. A button owns its channel.

Only changes arrive

The phone sends a channel when its value changes, not continuously. Before the first change read() returns the element's default. A button press always arrives, even if the value is the same as last time. Values flow only while the experiment is running (▶ in the app) — an edit made while paused reaches the board when the user starts again. experiment.setResendUnchanged(true) makes the phone write every channel on every analysis cycle instead (about a hundred times per second), which is useful as a heartbeat from the phone.

Elements

element	constructor	setters
Edit	Edit(label, channel)	setDefault(v), setUnit, setSigned(b), setDecimal(b), setMin(v), setMax(v), setFactor(f), submitWith(button)
Slider	Slider(label, min, max, step, channel)	setMinValue, setMaxValue, setStepSize, setDefault, setPrecision(n), setShowValue(b), setColor
Dropdown	Dropdown(label, channel)	addOption(text, value) (up to 8) or setOptions(n, labels, values) (any number), setDefault(value), setColor
Toggle	Toggle(label, channel)	setDefault(0 \| 1)
Button	Button(label, channel)	setValue(v) — what a press writes, default 1 — and onPress(fn)

All have setLabel, setChannel, onChange (not meaningful for a button), setVisibility and setXMLAttribute.

A form with a submit button

edit.submitWith(button) delivers the field only when that button is pressed:

PhyphoxBleExperiment::Button apply("Apply", 5);
PhyphoxBleExperiment::Edit setpoint("Setpoint", 6);
setpoint.submitWith(apply);
setpoint.onChange([](float v) { target = v; });   // fires once per press, with the field's value

Set the button's channel before calling submitWith.

From the remote interface

phyphox's remote access (the web interface and its API) can write these channels too: an edit field corresponds to cmd=set, a button to cmd=trigger. The board sees no difference.