02 1WIRE

1WIRE Mode

This mode allows communication with devices using the 1-Wire protocol, such as iButtons, EEPROM or temperature sensors (e.g. DS18B20).
It supports basic scanning, reading, writing, and sniffing features.

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🧩 Commands

Arguments in < > are required, while arguments in [ ] are optional.

Command	Description
scan	Detects and lists all devices found on the 1-Wire bus with their ROM IDs
ping	Sends a reset pulse and checks for presence response from a device
sniff	Passively monitors the data line, detecting timing patterns (reset, presence, bits)
read	Reads both the ROM ID and scratchpad of a connected device
write id [8 bytes]	Programs a new ROM ID to a supported device, prompt for 8 bytes if not given
write sp [8 bytes]	Writes 8 bytes to the scratchpad memory (via 0x0F command), , prompt for 8 bytes if not given
ibutton	Open an interactive shell to copy, read and write iButtons (RW1990)
eeprom	Open an interactive shell to dump, read write, analyze and erase EEPROM (DS24/28)
temp	Reads and decodes the temperature from a connected DS18B20 sensor
config	Lets you change the data pin used for 1-Wire communication
[0xAA r:8] ...	Allows sending manual 1-Wire instructions with precise control over command flow

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⚙️ 1-Wire EEPROM Shell

The eeprom command provides an interactive environment to explore, manage, and erase 1-Wire EEPROM chips.

Actions

• 🔍 Probe EEPROM – Detects the connected 1-Wire EEPROM and identifies its model and size.
• 📊 Analyze EEPROM – Scans the contents for data summary.
• 📖 Read bytes – Reads a sequence of bytes starting at a given memory address.
• ✏️ Write bytes – Writes one or more bytes to a specific address, with automatic page handling.
• 🗃️ Dump EEPROM – Outputs the entire EEPROM contents in hex dump format.
• 💣 Erase EEPROM – Wipes the chip by writing 0x00 across all pages.
• 🚪 Exit Shell – Leaves the 1-Wire EEPROM shell and returns to the previous menu.

Supported Models

Model	Capacity	Page Size	Family Code	CRC16	Notes
DS2431	128 B	8 B	0x2D	✅	1 Kbit – 4 pages of 8 bytes
DS2433	512 B	32 B	0x23	✅	4 Kbit – 16 pages of 32 bytes
DS28EC20	2560 B	32 B	0x43	✅	20 Kbit – 80 pages of 32 bytes

• Only one device should be present on the 1-Wire bus during operations.
• Pull-up resistor is required on the DQ (IO) line.
• 

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📝 Notes

• You can use scan to discover devices like DS18B20 or iButtons.
• The read command shows the device's ID and scratchpad if supported.
• The write id and write sp commands expect 8 bytes in hex format (e.g. write id 0x01 0x02 0x03 0x04 0x05 0x0 0x07 0x08).
• Without data provided, the write id|sp commands will prompt for 8 bytes.
• The ibutton implementation follows the official Dallas 1-Wire protocol for ID programming, including the proper timing sequence and command structure.
• Prefers USB Serial over WiFi web to copy ibuttons, the timing is critical and the web server could disturb the copy.
• sniff is useful when passively monitoring a 1-Wire bus connected to another master device. It attempts to automatically detect known 1-Wire timing patterns, including reset pulses, presence responses, and bit-slots, to reconstruct readable transactions.
• ibutton Operations on Rom ID for classic iButtons. Works with RW1990 tag (rewrittable)
• The instruction syntax ([0x... r:N]) allows precise control of low-level communication, including bit-level reads, delays, and raw hex sequences.

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📌 Example Usage

mode 1wire
scan
read
sniff
write id 0x1 0x2 0x3 0x4 0x5 0x6 0x7 0x8
write id # Prompt for 8 bytes: AA BB 01...
write sp
write sp 0xDE 0xCD 0xAA 0x4 0x5 0x6 0x7 0x8
temp
ibutton   # open interactive shell
eeprom    # open interactive shell
[0x33 r:8] # Send read cmd and read 8 bytes

▶️ Demo

🔧 Hardware