Experiment 7: Analyzing 1-Wire Protocol

Objective: Understand the 1-Wire communication protocol, including its timing characteristics and data structure, and learn to decode its signals using a logic analyzer.

Steps:

1. Connect the Logic Analyzer to the Data Line:
   • Identify the 1-Wire data line on the device under test.
   • Connect the logic analyzer probe to the data line.
   • Ensure a proper ground connection to avoid noise and ensure accurate signal decoding.
   • Verify the presence of a pull-up resistor on the data line, as it is essential for proper 1-Wire communication.
2. Set the Software to Analyze 1-Wire Protocol:
   • Open the logic analyzer software and select the 1-Wire protocol decoder.
   • Configure the decoder settings, ensuring they match the timing requirements of the 1-Wire protocol (standard speed or overdrive mode).
   • Prepare the device under test to generate 1-Wire communication activity (e.g., by initiating a data read/write sequence).
3. Capture and Decode Data Packets:
   • Start capturing the signal from the 1-Wire bus using the logic analyzer.
   • Analyze the waveform to identify reset pulses, presence signals, and data frames.
   • Verify the data integrity and structure, including the ROM commands, memory operations, or sensor readings.
   • Compare the decoded data with expected values or the device's datasheet for validation.

Expected Outcome:

By the end of this experiment, you will understand the fundamentals of the 1-Wire protocol, including its unique timing and data structure. You will also gain hands-on experience in capturing, decoding, and troubleshooting 1-Wire communication using a logic analyzer.