1
Open Bench Logic Sniffer / Re: Potential Buyer :P
I'm far from knowing much about electronics engineering, but in my searches for inexpensive test equipment I have pretty much found that there is absolutely nothing that can do real-time monitoring of a moderate-speed signal while also being able to save it (like, you could have real-time monitoring of a signal with an old analog oscilloscope, but it won't save the signals). What you need to decide is whether the signals you are trying to debug are able to be reproduced, and how much memory you will need in order to save the smallest chunks of the signal that you can use. If the signals are not reproducaeble, then you need to be able to save the whole signal, which might require a huge amount of memory. If the signal can be reproduced, then having a small amount of memory might be OK if you can trigger at each chunk of memory that fits in the buffer.
I have seen a few USB logic analysers/MSOs that can do "continuous capture", but the signal speed is very low in those cases. Some of them only utilize USB 2.0 full-speed (only like 11 or 12Mbps, which without USB overhead would only give you a max of a 6MHz signal, though it would really come out lower... maybe 4MHz?). Most of the inexpensive USB LAs have terribly low sample depths. The lower-end professional equipment (~$700-1000USD, though you may have to pay extra to buy modules to actually decode I2C/SPI/UART/RS-232 signals into the hex/decimal data) tends to have around 1MB per channel.
I recently discovered the Pipistrello, which has 64MB of LPDRAM and is capable of running a ported OBLS bitstream. I managed to get one during the last run of them. Unfortunately, they cost 3 times as much and are only available for limited runs every so often (I think this last run might already be sold out after a week). If you need a huge amount of sample memory and are interested in experimenting with FPGAs, then it might be a good choice. Otherwise the OBLS or a Papilio with the OBLS bitstream would be a good choice.