@PlasmaHH For my wedding, one of my groomsmen got me a tube of 555's as a joke
@Mike looks pretty good - a bit of detection code and you should be in business
A thought: look at how long each rising and falling edge is (probably 5-20 samples?).
Once you know that, you can do a really simple level detection algorithm. For example:
If you have an array of 10000 samples, and you know that it takes less than 10 samples for one of the fast transitions, then I would pseudo-code it as:
x = data[0 to 9,999]
for t in range(9,989):
delta = x[t] - x[t+10];
if delta > threshold_1:
pump_1_count++;
if threshold_1 > delta > threshold_2:
pump_2_count++;
Of course that will probably need some tuning to prevent multiple increments per edge, etc... etc...
@Mike If you are using USB to power the thing, why not use a USB to UART cable and a little microcontroller that feeds some simple data straight into the tablet?
microcontrollers are largely software, that's your field of expertise ;o)
Ah I see you found Arduino and the likes in the mean while yourself. You don't need a full Arduino, you only need a small 8-pin controller for a job like this. Although Arduino (or a similar board like the other one you linked) is much easier to use.
@W5VO nice, I didnt get anything geeky for my wedding :/ the nearest thing I ever got was an atx power supply case as gift wrapping... it was one that almost went up in flames... the gift was nice too... a tshirt with "No I won't fix your computer" on it... made my time at university definetly more enjoyable...
@PlasmaHH Pretty powerful for the price point. I don't care for the measurement display that never really entirely clears until you reboot. Haven't checked out all the probes, but the two I've used are certainly functionable.
@W5VO It's also hackable to do some nice things, but I'm not going to do it.
@PlasmaHH I bought it from Saelig, which is local for me, so I picked it up at their site. Chatted up a sales rep, maybe about retooling our student lab. Looks like I'd have a hard time spending a grand US on a student scope these days. Our 4-channel tek student scopes were about $1200 when I bought them in quants of 12!!
@PlasmaHH You can remove them, but say you put up three and remove the first two. They'll appear as greyed out on the bottom line -- not just gone. A bit annoying. My understanding is that the greyed out ones scroll off as you add more.
@ScottSeidman ah that you mean. yes the greyed out get removed if you add more. I think it is greyed out because you can chose to recover. chosing F6/delete all will remove all and then you can add new ones "fresh"
@PlasmaHH I gave up designing circuits with rise times. I just use fall times. I start at 10 volts, and only move down. I find that if I can't get done what I need to do by the time I hit ground, it wasn't worth doing in the first place.
Hmm, I have only tested on my PC, not on the tablet... I wonder if it will be better
Is the victim's value always set to the difference or is it relative?
Meaning, if the victim is in the process of dragging down to 0v and is at -1v and the source increases in voltage by +5v, will the victim go to +5v or +4v?
@PlasmaHH To be clear, if the source increases to 2v, the victim will rise to 2v, then fall back to 0v. After the victim falls back to 0v, if the source rises to 5v (increase of 3v) the victim will rise to 3v then fall back to 0v. Right?
I thought of a way to check the code as well. If I see a downward spike and I determine that it came from flow meter 1, I can make sure that flow meter 1 is in the "ON" state as I have just detected that it has switched to the "OFF" state. If it was already in the "OFF" state then it is impossible for it to cause a downward spike and I know something went wrong.
I was going to make a stir plate to grow yeast for brewing beer. It involves using some type of housing (cigar box, wooden box), wiring some DC voltage to a switch, to dimmer controller, to a PC fan inside the box. On the center of the fan, you glue magnets. When the magnets rotate, that rotat...
When I see a peak it is difficult to tell what has just happened because some of the change of states have a very similar change in voltage.
For example, if I saw an edge that was a voltage change of -1.5, that is right in between 1-> 2 and 0 -> 1. Meaning, I wouldn't know if:
A. flow meter 1 was on, and now flow meter 1 is off and flow meter 2 is on (1 -> 2). - OR - B. No flow meters were on and now flow meter 1 is on ( 0 -> 1).
Well, actually. If I know the state of the flow meters I could determine what happened. For example, If I know that flow meter 1 was already on, case B is impossible and it must be case A.
In the same way, if I know that flow meter 2 is already on, case A is impossible and it must be case B.
I was going to make a stir plate to grow yeast for brewing beer. It involves using some type of housing (cigar box, wooden box), wiring some DC voltage to a switch, to dimmer controller, to a PC fan inside the box. On the center of the fan, you glue magnets. When the magnets rotate, that rotat...
