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Topic: PAW13 - Sniff-A-Lot for BusPirate (Read 5351 times) previous topic - next topic

PAW13 - Sniff-A-Lot for BusPirate

As PAW13 I did a small addon board to the Bus Pirate.  Sniff-A-Lot combines both TX and RX of a serial port into one signal that can be monitored by the Bus Pirate.

This works as long as RX and TX is not transmitting simultaneous (Full Duplex). In most cases the communication is only Half Duplex. where the computer sends a command to the device and the device replies and this gets repeated.

The Sniff-A-Lot handles a both a real RS-232 +/- 12volt communication as well as TTL-level serial comms - both with Idle High and Idle Low versions.

I've sent for the PCBs and they should arrive any day so I can solder one up and test it.


Re: PAW13 - Sniff-A-Lot for BusPirate

Reply #1
Ok, I got the PCBs today and soldered up one of them.  Now I just need to find my Bus Pirate to do some testing - I'm sure I've got it somewhere here.... :-)


Re: PAW13 - Sniff-A-Lot for BusPirate

Reply #2
Hi Mats;
  put me down for a couple of PCB's.

Mick M

Re: PAW13 - Sniff-A-Lot for BusPirate

Reply #3
Sure Mick, I'll just add them to the envelope I'm posting to you tomorrow anyways.

So, I found my Bus Pirate and then made a RS-232 breakout cable with a male/female DB9 and tapped off rx/tx from pin 2/3 and gnd from pin 5.  And hooked it up to the first serial device I had in reach - a magstrip card reader/writer (cloning credit cards much? ^_^)

The reader/writer was working even after I plugged in the tap cable and I was able to see both the data sent from the computer and the replies from the unit on the Bus Pirate terminal window.  Success!

So the with this unit the Bus Pirate is able to read data from a real high-voltage RS232 serial port, and this on both the tx and the rx lines.

I haven't tried the TTL-Serials yet, but I have no doubt that they will work as well.



Re: PAW13 - Sniff-A-Lot for BusPirate

Reply #4
Hi -

Diodes D3 and D4 are backwards.

R4 will pull MIX-TTL_HI to VCC and it will stay there unless you reverse the diodes.


Re: PAW13 - Sniff-A-Lot for BusPirate

Reply #5
B-b-b-but it looks like the D3/D4 pair is pointing in a different direction than the D5/D6 pair on the schematics :-( and/or :-)

Ok, I can fix that with some manual hacking of the silkscreen on the pcb's I've got.  And I'd better update the schematics and pcbs for if/when I order more of them.

Thanks for noticing the bug.

(PM me your address and I'll send you a kit if you want one.)

Re: PAW13 - Sniff-A-Lot for BusPirate

Reply #6
Finally proof that matseng is human after all. I was already wondering, after seeing so many beautiful things from him, that he might not pass the Turing-test.

(I still have to get my first versions of a PCB design right, still room for improvement after 30 years)


Re: PAW13 - Sniff-A-Lot for BusPirate

Reply #7
Very nice work as always Mats, looks like a very handy one.