• I2C
  • Beginner
  • 10 min
  • Serial CLI

Recipe · Beginner · I2C

How to dump an I2C EEPROM

A small board had an 8-pin serial EEPROM and I needed a backup before changing anything. The goal was to detect the chip geometry, read bytes, then dump the content in a controlled way.

I2C EEPROM chip on an I2C bus.
Probe the chip first, then dump it through the dedicated EEPROM shell instead of guessing register reads.

Wiring View

EEPROM BP SDAI2C SDA GPIOSCLI2C SCL GPIOVCCcorrect supplyGNDBP GND
Generated from the wiring summary: EEPROM to BP.
Step 1

Commands

Run the typed commands first. If the command opens an interactive shell, select the named action from the shell menu instead of treating it as another CLI command.

Result

What success looks like

A successful probe means the chip ACKed and the shell can use an EEPROM-aware workflow for read, dump, analyze or erase actions.

Troubleshooting

  • Forgetting that many EEPROMs use 0x50 by default, but address pins can change it.
  • Trying raw register reads before confirming addressing size.
  • Writing before making a backup.
  • Using long wires without pull-ups or shared ground.

Next steps

  • Use Probe first inside the EEPROM shell.
  • Use Read bytes on a small range before dumping everything.
  • Use Dump EEPROM only after the probe result is stable.

I2C EEPROM dump FAQ

Why probe before dumping the EEPROM?

Probe first so the shell can confirm the chip responds and choose a sensible geometry before reading. Serial EEPROM families differ in density, address width and page behavior, so a blind raw dump can wrap or miss data on the wrong assumptions.

Is 0x50 always the EEPROM address?

No. Many 24xx parts use a base 7-bit address near 0x50, but address pins and larger memories can make more than one address respond. Scan first, then open the EEPROM shell with the address you actually found.

Can a dump damage or change the EEPROM contents?

A read-only dump should not change contents, but wrong voltage, wiring mistakes or accidental write/erase actions can. Treat unknown boards as evidence: back up before writing, check write-protect pins, and avoid erase actions until the dump is verified.

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