Hi, Xprotolab users and experts,/\r\n//\r\n/I have recently purchased Xprotolab mini oscilloscope. Item is nice and has useful logic analyser and AWG functionality (although limited in frequency) for it's size.
For information, I have Xprotolab with SW version 2.26 and micro USB connection (newer HW version).
/\r\n/I wanted ask few questions and make few comment with regards to Xprotolab:/\r\n/ 1) I noticed that I cannot find a way to exit protocol sniffer on SPI mode. All protocol options starts by showing setup in the top left corner and then displays a split screen with retrieved data. To exit the mode, MENU key (K4) should be pressed. However, with nothing hooked to Xprotolab SPI pins, no key combination exits SPI mode. I had to reset device completely to go back to normal mode./\r\n/ I discovered this "bug" on SPI, and checked against other modes - UART, I2C, IrDA, 1 wire, MIDI. Only SPI has this behaviour.
EDIT: this issue arises from powering Xprotolab with ungrounded PC. Xprotolab has no "bugs". See below
/\r\n/ 2) There are 3 additional protocols on protocol sniffer menu: IrDA, 1 wire and MIDI. These are undocumented in Xprotolab manual, so I do not know which pins to use for these protocols and what are the capabilities of additional modes.
/\r\n/ 3) I would suggest to change "SUBTRACT" mode to "ADD" mode, as it is on most oscilloscopes. Then CH1+CH2 would be ADD of CH1 and CH2, CH1-CH2 would be ADD of CH1 and inverted CH2.
/\r\n/I would like to hear if somebody knows how to deal with questions 1), 2) and to hear opinion on 3).
EDIT: topic was edited to fit issues found.

1) I noticed that I cannot find a way to exit protocol sniffer on SPI mode.
This should not occur. What settings are you using? Is there activity on the logic channels?
2) There are 3 additional protocols on protocol sniffer menu: IrDA, 1 wire and MIDI. These are undocumented in Xprotolab manual, so I do not know which pins to use for these protocols and what are the capabilities of additional modes.
These protocols are not yet implemented.
3) I would suggest to change "SUBTRACT" mode to "ADD" mode, as it is on most oscilloscopes. Then CH1+CH2 would be ADD of CH1 and CH2, CH1-CH2 would be ADD of CH1 and inverted CH2.
This would be easy to change, but I think it is a matter of style. If I get more feedback from other users I can consider changing it.

>>1) I noticed that I cannot find a way to exit protocol sniffer on SPI mode./\r\n//\r\n/>This should not occur. What settings are you using? Is there activity on the logic channels?/\r\n//\r\n/I put Xprotolab on SPI mode with no inputs connected and then cannot get out of this mode./\r\n/Exact settings:/\r\n/CH1 on, CH2 on,/\r\n/Logic off/\r\n/No pull up or pull down/\r\n/Protocol SPI/\r\n/ Clock - rising/\r\n/ Phase - risign (first transition)/\r\n/ Invert SS - ON (with OFF I can exit this mode easily)/\r\n/ Normal/single/circular - any combination/\r\n/

I can't reproduce this
Try restoring the settings from the factory options, then try again. If this still occurs, let me know how to reproduce it step by step, with the initial step being restoring the factory settings.

First of all, thanks for replies above./\r\n//\r\n/I followed your recommendation to go back to known state and reproduce step by step procedure which leads to potential problem. So,/\r\n/0.1) Xprotolab AWG generator is connected channel 1, channel 2 and logic inputs are disconnected/\r\n/0.2) Power is provided by USB cable to PC, Xprotolab is not turned on (USB device is recognised on startup)/\r\n/1) I restored factory defaults (hold K4 during startup, then K3)/\r\n/1.1) device turned on in default oscilloscope mode. Some untriggered sin wave is on CH1, CH2 is flat./\r\n/2.1) go straight to Menu->Logic->Protocol->SPI-> turn option "Invert SS" with K3->start sniffer/\r\n/OR/\r\n/2.2) Menu->Logic->Protocol->SPI->CPHA is change with K2->turn option "Invert SS" with K3->start sniffer/\r\n/3) then one of the following happens:/\r\n/a) top left screen show pin settings -> screen doesn't change, buttons do not affect anything, cannot exit this mode/\r\n/b) split screen shows up, some FF data are written to first few lines -> buttons do not affect anything, cannot exit this mode/\r\n/c) same as in mode b), but after some time K4(menu key) press exits this mode back to oscilloscope mode./\r\n//\r\n/I hope this is reproducible on other devices with SW 2.26.

No, I still can't see the bug occurring. Perhaps you have a defective unit.
This sounds like if there were activity on the logic channels, is there any activity when you turn on the logic channel display?
Can you verify that all the logic channels work? Try probing a digital clock or maybe just the 3.3V from the board.
Can you visually inspect the board for short circuits or soldering defects?