Few weeks ago there was an article on Hack A day describing how a Chinese clone Saleae could be used as a USBee. It got me pretty excited because ive always wanted to get my hands on that logic analyser. However the $150 cost has kept me at bay. Aliexpress has these clones for sale but shipping to India is almost $15, I stumbled upon a CY7C68013A development board that the seller says can be used as a logic analyser not Saleae. The board is sold as an lcsoft development board, so technically it does not violate any terms.

The bad part however is that the new Logic Software for Saleae employs a method to detect these boards. The error that appears is:

Error: LogicAnalyzerDevice::ReadEeprom failed after 3 tries.

After hours and hours of experimentation I found that the EEPROM is at fault. This happens because the device repeatedly tries to read the EEPROM thrice, if the EEPROM is slow, in case of clones it is. An error is generated. The solution is to replace the EEPROM with a quicker one. First step is to desolder the smd AT24c128 and replace it.

The new EEPROM can be soldered on a seperate board in case its not SMD, just as in my case. The SCL and SDA wires can be obtained from the pin header. Configuration for A0 A1 and A2 are:

A0 – +3.3v
A1 – GND
A2 – GND
A3 – GND

I can not say what eeproms will work, its a case of trial and error. I had a few 24c16 from Atmel to hand which seemed to do the trick. The new EEPROM must however be written with the correct VID and PID of the logic analyser in the first 8 bytes as explained here. This can be done easily with a tool like the PIC Kit2 or the JDM eeprom programmer.

Finally a few shots of the memory bank and input board. I used a series resistor and clamping diodes to protect the board from over voltage mishaps.

The top is a messy because I learnt the hard way, EEPROMs address bits will not let me switch. Used the Data line to switch between them. USBee and Saleae are now selectable!

Clamp Circuit:

All housed and ready:

If you think this isn’t for you, buy the real product if you can afford it. http://www.saleae.com/home/