Category Archives: Electronics

Reprogramming SFP modules

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I needed a fiber connection to my HP 2824 switch, but it would not allow me to use non HP SFPs.

So what did I do? I reflashed a D-Link DEM-311GT using the EEPROM data from an HP SFP using a Raspberry Pi (and an old broken switch as a breakout board for the SFP).

Switch as SFP breakout board

The EEPROM in the SFP is just an ordinary I2C EEPROM (basically the same as is used for the EDID in monitors).

There was one problem though: the DEM-311GT SFP was write protected, so I had to solder a wire to the write-protect pin to make it writeable.

DEM-311GT with patched write-protect

 

Cutting PCBs

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Since I put three designs on a single 10x10cm PCB I need to cut it.

First try with the hacksaw was successful but it was really close to some traces.

Will try to get access to the metal shear and see if that works better.

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