Got to say I love the slo-scope application, sure it has limitations but overall great work guys!
One thing that really bugs me (no pun intended) is that pretty much maxes out the CPU after a run and forever more thereafter.
Can you release a new version that has the application returning to an idle state after a run? I’m sure it’s just a case of putting a System.Threading.Thread.Sleep() in somewhere.
Thanks in advance 
Ian.
Hello Ian,
Thanks for the bug report; I’ll look into it. I will also make sure we release the source code for the application soon (I keep meaning to nicely comment everything before releasing it, but I think maybe it would be better to just get it out there).
- Ben
Hi Ben,
Um, the never ending pain of tidying up code and commenting. The last 10% of a project often takes 90% of the time; you have my full sympathy! When I worked in the s/w business I used to hate releasing undocumented/commented code almost as much as I hated doing the documentation. Sometimes I used the line “my code is so good it is self-documenting”! I don’t know if many people fell for it but there is some validity there.
Thanks for the reply, the slo-scope is such a cool and useful application; an inspired idea. I’m sure people would buy the USB Programmer for this feature alone if you promoted it. I’m using it as a simple logic analyser for debugging some IR stuff and it’s proving invaluable.
Great work, keep it up.
Ian.
Hi Ben,
I just bought a AVR programmer & Wow, the SLO-scope looks like a really cool little toy ! props to whoever thought of it !!!
Would you consider releasing the VS C# PC app so we’d have something to play with in accessing the SLO-scope’s data ? (also the AVR firmware for those of us who like to look under the hood & get into code innards)
TIA, Karl
Hi Ben, I want to attach the SLO-scope inputs to my '93 Chrysler’s CCD OBD1 under-dash DLC (Data lLink Connector), a differential twisted pair signal with 250 ohms impedance, so I’m wondering what the input impedance of the two SLO-scope analog ports is to determine it’s loading effect on the CCD bus signal.
BTW, the CCD (for Chrysler Collision Detect) bus is how the various 10 or so Chrysler computer control modules inter-communicate.
TIA, Karl
Hello, Karl.
I’ll try to make the SLO-scope Visual C# project available tomorrow; I’ll make a post when it’s up.
What AVR firmware are you referring to? In what could be viewed as an interesting twist, the USB AVR programmer actually uses a PIC to program AVRs! I certainly understand wanting to see what’s going on under the hood, but we will not be making the programmer firmware public.
- Ben
The only spec I have on this right now is that the recommended maximum impedance of an analog voltage source is 2.5k. Is this good enough for you or should I try digging around more for the actual input impedance?
- Ben
In the pololu_usb_avr_programmer.pdf on the lower pane of the Sloscope pic on pg 30 of 36, there are 2 white “x” marks on the waveform that I can’t seem to find a reference to in the text. Any ideas ?
Just found the answer myself - they are index marks for where you mouse-over the waveform, for more exact readings.
I really don’t need the pic firmware code, I was only off-handedly curious to look under it’s hood. It’s data is all u/l’ed (uploaded) to the pc anyway, & with the VC# pc app, we have access to all the data, which is all that’s important.
Nice job on that VC# pc app, & thanks for making it available for those of us that want to manipulate that data, etc. I can’t wait !
TIA, Karl
I found an answer to the A & B SLOscope input impedance on pg 26 of 36 of the pololu_usb_avr_programmer.pdf, where it says: “By default, pins A & B are high impedance inputs that…”.
The SLO-scope client source code is now available (see the last file under the resources tab)! If you have any problems understanding how it works, please ask.
- Ben
