Command-Based ADC Sampling with Timers, Actions & CRC Integrity

Overview

This project showcases how to integrate binary data parsing, custom serial actions, timed execution, and checksum validation in a Serial Studio workflow using Arduino. It provides a complete example of how to build a robust, command-driven interface for sensor data acquisition, suitable for real-time plotting and FFT analysis.

The Arduino collects analog readings from six input channels (A0 to A5), processes the values, wraps them in a binary protocol frame with a CRC-16-CCITT checksum, and only sends data when explicitly commanded using a custom "poll-data" action. Serial Studio triggers this action either manually or via timer modes like auto-start or toggle-on-trigger.

Key Features

• Binary Data Parsing: Efficient, low-overhead serial communication
• CRC-16 Checksums: Ensures data integrity on each frame
• Action System: Serial Studio dashboard buttons that send predefined commands
• Timer Modes: AutoStart, Toggle, and Triggered transmission
• FFT Visualization: Analyze analog noise or sensor signals in the frequency domain

Compatibility

Works with any Arduino board featuring analog input pins. No external components required—floating analog pins generate natural noise, ideal for FFT demonstrations.

Hardware Setup

Connections

• Leave A0–A5 unconnected to capture environmental noise.
• Alternatively, attach sensors or function generators for signal injection.

Step-by-Step Guide

1. Arduino Sketch (HexadecimalADC.ino)

This sketch configures the ADC, listens for serial commands like "poll-data", reads analog values, computes a CRC, and sends data over serial only when asked.

Frame Format:

• Start delimiter: 0xC0 0xDE
• Sensor data: 6 bytes (mapped 10-bit → 8-bit)
• CRC-16-CCITT (2 bytes, big-endian)

Baud Rate: 115200

Trigger via Serial Studio Actions:

• poll-data: Read and transmit 1 data frame
• enable-pull-up: Enable pull-ups on A0–A5
• disable-pull-up: Set A0–A5 to normal input mode

2. Serial Studio Configuration

Frame Format

• Mode: Binary (direct)
• Start Sequence: 0xC0 0xDE
• Checksum: CRC-16-CCITT

Actions

You can define custom actions in your .json project to send:

• "poll-data" on button press or toggle
• "poll-data" automatically using timer
• Other configuration commands on connect

JavaScript Frame Parser

/**
 * Convert each byte (0–255) into a voltage between 0 and 5V.
 */
function parse(frame) {
    let dataArray = [];

    for (let i = 0; i < frame.length; ++i) {
        let byte = frame[i];
        dataArray.push(byte * 5.0 / 255);
    }

    return dataArray;
}

For help on the parser function, see the Serial Studio documentation.

3. Visualize with FFT

1. Start Serial Studio.
2. Select the serial port.
3. Set baud to 115200.
4. Click your "poll-data" action.
5. Use the FFT widget to inspect signal frequency.

Troubleshooting

• No output: Ensure poll-data is being sent.
• Noisy values: Normal for floating pins; connect sensors for better control.
• Invalid frames: Check CRC settings and delimiters.
• Slow updates: Increase timer rate or switch to manual polling.