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      DrM replied to the thread Teensy 3.2 End Of Life.
      @PaulStoffregen First, aside, Paul have you tried that ADC we talked about somet time ago? That one has a mux and can share one opamp for all of the channels. I will post or send you the design files if anyone is interested, with the...
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      A new repos, or rather an old repo with new content is posted to github. https://github.com/drmcnelson/Arduino_Timing There you will find some measurements for timing for digital write, read, toggle, SPI transfers, interrupt latency and so...
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      DrM replied to the thread Send data from Teensy to Python.
      Two comments, one is a correction to my previous. If you can serialize your exchanges, then that is a third approach. Bottom line, it is about getting the data from he driver before the internal buffer in the driver runs out of room. Re the...
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      DrM replied to the thread Send data from Teensy to Python.
      I regularly send about 4000 values, in either binary using write or formatted using print. You can see my code for one example of this at: https://github.com/drmcnelson/Linear-CCD-with-LTSpice-KiCAD-Firmware-and-Python-Library There is a...
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      I know the spec is thru hole, but SMT is really not that hard. Reflow ovens are on ebay for even $200, get some nice solder paste and tweezers and a magnifier (wearable is nice), and stick with doable size parts, at first. It really is...
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      Similar idea, the 74LVC1T45 are nice. You have voltage on each side, and a direction pin. I run VD to the interface connector so the other end can tell me what power it is using.
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      @MarkT, yes I appreciate the challenge. That is why there are researchers working on the kT/C noise challenge. Maybe some major breakthrough in dieliectrics will give us a smaller 10pf some day, or some other way to store charge linear in V...
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      SPICE models for the Teensy4 ADC Input @MarkT - this addresses the points you raised, I hope. The last figure I think might explain why that sampling cap is only 2pf, besides that it is only 12 bits. The Teensy3.2 had 10pf for 16 bit mode...
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      • Teens4SAR_slow_fast_thermistor.png
      • Teens4SAR_slow_slow_thermistor.png
      • Teens4SAR_bufferd_fast_fast_thermistor.png
      • Teens4SAR_bufferd_slow_fast_thermistor.png
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      @MarkT - i see the confusion, it is not about a slow or fast changing signal, it is about the sampling window of the SAR. You could say the switch makes it a fast changing signal, so-to-speak. Notice that the spice model has a DC level on the...
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      @MarkT, could you show how that works? To check, you said 100nf from input to ground, right? Like this??? It seems like 100nf means you now have a time constant of about 1msec. That would mean you now need order 10 milliseconds before...
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      @Paul hi, hopefully this is helpful. I wasn't sure which to which forum it should be posted. Suggestions?
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      There are a lot of posts on this and many other forums that go something like "Why am I getting incorrect readings or weird behaviors from the analog input?" And there are lots of responses that go something like, just use this code. If that...
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      The problem, not mentioned in that tutorial, is that the analog input is a SAR type ADC. I recall the sampling capacitor for the Teensy 4. is something like 30 or 40 pf. They almost always are in that range because of the famous kT/C noise...
      • SAR_thermistor10K.png
      • SAR_opamp_R100_cropped.jpg
      • SAR_opamp_RC20x1_cropped.jpg
      • SAR_opamp_RC20x1_currents_cropped.jpg
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      DrM replied to the thread Multiple Analog Inputs.
      How are you interfacing the microphones to the analog input pins?
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      Hi, I would like to announce a new project. The goal could be described as "open science", or at least the part that is about being able to make physical measurements and build experiments when you are not necessarily at an elite institute or...
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