Recipe 4 — Continuous vs Frames Modes¶

Continuous mode appends samples to a scrolling history, while Frames mode replaces the visible packet with the latest complete frame. In ViewPoint, continuous draws new data with each point, while frames draws only after the full data set has been received — defining the frame rate. See Update Modes.

This recipe uses the same burst-shaped data in both sketches. The burst center stays fixed so the screenshots emphasize update behavior rather than motion.

Continuous mode¶

#include <ViewPoint.h>
#include <math.h>

const int PACKET_SIZE = 256;

float burstCenter = 40.0f;

float burstValue(int i, float center) {
    float d = i - center;
    float pulse = expf(-(d * d) / (2.0f * 8.0f * 8.0f));
    float ripple = 0.08f * sinf(i * 0.35f);
    return pulse + ripple;
}

void setup() {
    view.begin();
    view.setDelay(2);
    view.setTitle("Continuous: point-by-point drawing");
    view.setPlotTitle("Moving Burst");
    view.setHorizontalRange(0, PACKET_SIZE);
    view.setVerticalRange(-0.2, 1.2, 0.2, 0.5);
    view.setAxisLabels("Sample", "Amplitude");
}

void loop() {
    for (int i = 0; i < PACKET_SIZE; i++) {
        view.addData("Burst", burstValue(i, burstCenter));
        view.send();
    }
}

Frames mode¶

#include <ViewPoint.h>
#include <math.h>

const int PACKET_SIZE = 256;

float burstCenter = 40.0f;

float burstValue(int i, float center) {
    float d = i - center;
    float pulse = expf(-(d * d) / (2.0f * 8.0f * 8.0f));
    float ripple = 0.08f * sinf(i * 0.35f);
    return pulse + ripple;
}

void setup() {
    view.begin(frames, PACKET_SIZE);
    view.setDelay(120);
    view.setTitle("Frames: full-packet replacement");
    view.setPlotTitle("Moving Burst");
    view.setHorizontalRange(0, PACKET_SIZE);
    view.setVerticalRange(-0.2, 1.2, 0.2, 0.5);
    view.setAxisLabels("Sample", "Amplitude");
}

void loop() {
    for (int i = 0; i < PACKET_SIZE; i++) {
        view.addData("Burst", burstValue(i, burstCenter));
    }

    view.send();
}

What changes

Continuous: view.send() is called after every point. ViewPoint receives and draws the burst one sample at a time, so the plot behaves like a scrolling stream.
Frames: view.send() is called once after all PACKET_SIZE samples have been added. ViewPoint receives a complete packet and replaces the previous frame in one update.
Same data, different timing: both sketches generate the same burst samples. The visible difference comes from when send() is called and which update mode was selected in view.begin(...).

When to use this

Use Continuous for telemetry, sensor streams, and values that are meaningful as history.
Use Frames for FFTs, oscilloscope captures, histograms, display modes, and data where packet boundaries are meaningful.