sfp-eeprom-tool: CH341A-based SFP EEPROM reader and I2C sniffing to expose silent write failures
A small toolset that reads and writes SFP EEPROM over I2C with a CH341A programmer plus an I2C sniffer. The author found that sigrok/PulseView did not work with the analyser, that a v1.0.5 SFP coder firmware reported success while silently not writing the module (proven by I2C traces), and that the analyser software could not diff captures.
- Transceivers: SFP modules
- Form factor: SFP
Symptoms / messages:
coder reports success but does not write
I2C traffic analysis
Comments 1
Capture the I2C bus with a Saleae Logic 2 analyser and export CSV/logs to compare read vs failed-write sessions; this revealed the silent write failure of the coder firmware.