The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • DSO150: USB Serial Output

    Taking all those pictures of the DSO150 screen reminded me it has a data dump function: press the V/Div and ADJ buttons to squirt configuration, measurements, and trace data from the TX pad on the main board, just in front of the red-black power wires hot-melt glued in place:

    DSO150 USB serial adapter - interior
    DSO150 USB serial adapter – interior

    The picture shows the “before” stage, while I was figuring out where to carve another hole in the case.

    NB: The 113-15001-111 DSO150 firmware version includes the serial output option, so you won’t need third-party firmware. Similarly, current PCBs bring the serial pins to neatly labeled header pads. You should refer to the JYETech DSO150 / DSO Shell product page for the details.

    After all the cuttin’ and filin’ was done, it looked like this:

    DSO150 USB serial adapter - exterior
    DSO150 USB serial adapter – exterior

    The power switch on the back of the case (top of the picture) disconnects the lithium cell from the charge controller board (now tucked behind the battery) to eliminate any trickle current discharge. Charging the battery thus requires turning that switch on and turning the scope off with its own power switch (along its front edge). Capturing trace data requires having both switches on (duh), whereupon the scope’s normal operating current convinces the charge controller that the cell hasn’t reached full charge. Turn the scope off and, most likely, the controller will tell you the cell is fully charged.

    An intro blurb squirts from the port at 115200 in good old 8N1 format when you turn the scope on:

    DSO Shell
    JYE Tech Ltd.
    WWW.JYETECH.COM
    FW: 113-15001-111

    Pressing the V/Div and ADJ buttons dumps the trace data:

    VSen,0.5V
    Couple,DC
    VPos, -2.02V
    Timebase,0.2s
    HPos,00362
    TriggerMode,NORM
    TriggerSlope,Rising
    TriggerLevel,  2.02V
    RecordLength,01024
    Vmax,  2.85V
    Vmin,  0.24V
    Vavr,  0.87V
    Vpp,  2.61V
    Vrms,  1.03V
    Freq, 0.441Hz
    Cycl, 2.266s
    PW, 0.231s
    Duty, 10.2 %
    SampleInterval,00008ms
    00000,0000000000, 0.8518688
    00001,0000000008, 0.5273474
    00002,0000000016, 0.5273474
    00003,0000000024, 0.5476300
    00004,0000000032, 0.5476300
    00005,0000000040, 0.5476300
    << snippage >>
    01015,0000008120, 0.8113037
    01016,0000008128, 0.8315863
    01017,0000008136, 0.8315863
    01018,0000008144, 0.8315863
    01019,0000008152, 0.8315863
    01020,0000008160, 0.8315863
    01021,0000008168, 0.8315863
    01022,0000008176, 0.8518688
    01023,0000008184, 0.8518688

    It’s all in neatly comma-separated-value format, so you can slam it into a spreadsheet and have your way with it. Utilities also exist to capture the data, extract the values, and send them directly to GNUplot, etc.

    Like so:

    DSO150 test image
    DSO150 test image

    If I expected to do a lot of that, I’d boldify the traces and embiggen the text, all of which is in the nature of fine tuning.

    It’s hard to reproduce the beauty of the DSO150’s display, though:

    DSO150 test image
    DSO150 test image

    The DSO150 remains pretty good for being the worst oscilloscope I’m willing to use …