Hi all,
I'm a noobie learning how to reverse engineer embedded devices. One of the tools I've been using for the past year is my trust Saleae Logic 4, which I use to sniff UART ports on the devices I'm looking at.
However this Logic 4 has some limitations - it's quite slow at capturing data, which means I can't sniff JTAG or high speed SPI. So I'm looking for another logic analyzer that I can upgrade to.
So my use case is basically sniffing UART, JTAG and SPI signals. I might need to sniff other protocols later, such as CAN, USB and I2C. I'm not really sure how many channels I need at this point. Sometimes I also use my Saleae as a multimeter just to sniff out 3.3v signals and GND when looking for UART.
What's your recommendation? I've browsed around and there are the following choices:
- Saleae Logic Pro 8/16: pretty expensive, but the software is awesome and they support analog capture
- IkaLogic ScanaPLUS: cheaper, 9 channels, but maybe slower than Saleae and crappier software?
- DS Logic: pretty cheap, lots of channels, captures at almost the same speed as the Logic Pro ones, software seems OK
There's also another thing I don't really understand... how fast can these devices capture data? The data is all over the place, and sometimes it's mentioned in million samples per second, sometimes in MHz.
For example:
- Logic Pro: captures up to 500 million samples per second, but only supports 100 Mhz on 4 channels, and 25 MHz on 8
- IkaLogic: says it captures at 100 Mhz, but then they also say the maximum input bandwidth is 25 MHz (1 channel) | 16MHz (4 channels) | 10 MHz (All 9 channels)
- DS Logic: samples at 400 Mhz for 4 channels, but maximum input bandwidth is 50 Mhz
On top of all of this, it seems that the Saleae streams directly into the PC, while the other two seem to buffer the input. I guess this means I can only capture a small amount of data on the Ikalogic and DS Logic?
What are your thoughts?