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Type: Posts; User: Fenichel

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    pictures

    I'm sorry; I hadn't been aware of that rule. Here are pictures (in use) of the base station and two peripheral stations.275282752927530 The design is always evolving, so the "TV room" peripheral...
  2. That's implementation-dependent. Two standard...

    That's implementation-dependent. Two standard LZW routines should produce the same output, but one or both implementors might have diverged, thinking that the output was never going to be decoded by...
  3. It depends what you mean by "done line by line." ...

    It depends what you mean by "done line by line." Most of the output of an LZW compression is a string of 12-bit codes that capture the input, but there are also one or more 4096-entry tables that...
  4. The LZW method runs through the to-be-compressed...

    The LZW method runs through the to-be-compressed data only once, generating the output as it goes. An implementation that appears to be file --> file is coded with the primitives
    initialize
    get...
  5. All of the good compression algorithms are...

    All of the good compression algorithms are adaptive, so compressing an all-zero file is not very informative. The best compression routines for linear files and still images look for progressively...
  6. My unit had been running on a table that got...

    My unit had been running on a table that got occasional direct sunlight, but the display was -- does this make a difference? -- always faced away from the sun.
  7. e-paper hardware questions (slightly off topic)

    This is not exactly on topic, but this thread seems to have collected some members with e-paper experience that I'd like to draw on.

    I have an Adafruit e-paper display that I have been driving...
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    update

    This project has been variously updated. See https://www.fenichel.net/pages/Indoor_Activities/electronics/datalogger/datalogger.pdf
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    This expands on my previous answer about sampling...

    This expands on my previous answer about sampling rates. The key to tuning the system has been that all of the configuration information is on the uSD cards. The only numbers hardcoded into the...
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    This varies from sensor to sensor, but rarely as...

    This varies from sensor to sensor, but rarely as often as once a second. Remember, these are measurements of what is happening in & around an ordinary house. Why measure the temperature of a room...
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    [queued] modular datalogger system

    Several other forum members have described dataloggers for high-bandwidth datastreams, often status data from moving vehicles. I have completed a project that flexibly collects data from two or...
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    Yes, of course. I knew it would turn out to have...

    Yes, of course. I knew it would turn out to have been a slip at that bonehead level, but I stared at the code without seeing it. Thanks.



    Using .h & .cpp files makes a lot of sense when there...
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    addendum: the uSD card is 2GB, formatted FAT32...

    addendum:
    the uSD card is 2GB, formatted FAT32
    all of the example SD programs run without problem
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    T3.5: SD.open failing

    I have been having difficulty with a datalogger-style project; all of the code for the failing component is in the attachment. This component receives messages from remote components via XBee...
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    Thanks; that did the trick.. There is a ...

    Thanks; that did the trick..

    There is a

    #include <Arduino.h>
    line at the top of the main program, but I guess that its scope must be limited to that file.
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    "Serial1 not declared in this scope"

    I am trying to interface a Sparkfun particulate-matter sensor (their P/N SEN-15103) to a Teensy 3.2, using Teensyduino 1.48/Arduino 1.88 under Windows 7/64. To verify that the IDE recognizes the...
  17. solved

    I have answered my own question. I upgraded Teensyduino to 1.48, and that of course dragged in all the libraries. Now it compiles.

    Thanks to Paul & defragster for prompt patient attention.
  18. No, there's nothing in that folder but the...

    No, there's nothing in that folder but the readme.txt file that tells me
    For information on installing libraries, see: http://arduino.cc/en/Guide/Libraries

    It says it took each of the Wire...
  19. Teensy 3.2/3.1 Arduino 1.8.8 ...

    Teensy 3.2/3.1




    Arduino 1.8.8


    1.46-beta10
  20. ReadTest example in DS1307 library doesn't compile

    With no modification, the example doesn't compile. It begins

    #include <Wire.h>
    #include <TimeLib.h>
    #include <DS1307RTC.h>
    and that's enough to make the compiler complain. The compiler says
    ...
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    I am not sure why it might make a difference, but...

    I am not sure why it might make a difference, but I have cleaned up the anemometer.inc code to use an elapsedMicros variable instead of an unsigned long.
    // anemometer.inc
    /* routine IDs 23xxx

    ...
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    Thanks for the idea. I can see how wraparound...

    Thanks for the idea. I can see how wraparound might make usEarliestPossibleWindTurn falsely small, so that I might double-count a wave by (erroneously) counting the switch-bounce, but to get all...
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    difficulty with interrupt routine

    I am re-developing an environment-monitoring system that I first implemented with Arduinos. The system comprises a half-dozen or so peripheral stations, a base station, and a Windows application.
    ...
  24. problem explained and not fixed, but made tolerable

    The phenomena that made me start this thread seem to be similar to those shown in @Paul's video, so I suppose if they appear again, they will, after a while, go away again. For the moment, that's...
  25. Thanks to @Paul & @defragster for your rapid...

    Thanks to @Paul & @defragster for your rapid responses.
    My problem is gone, but unexplained. I reattached the Teensys to Windows to follow @Paul & @defragster's suggestions, but I was...
  26. Teensy 3.5s stopped supporting USB connection

    Two of my Teensy 3.5s (S/N 474530 & 493475, both with PID 0486), after working for several hours, are suddenly no longer recognized by Windows 7/64 as providing a USB connection, so they can't be...
  27. I thought of that, but I dislike using #defines...

    I thought of that, but I dislike using #defines to do more than set parameters. Using them to change the meaning of code makes me nervous. It's just a matter of style.
  28. solved

    A good solution turns out to be
    to not use Wire.h
    to not use WireKinetis.h
    to use i2c_t3.h
    to not use setSDA or setSCL, and
    to revise the Adafruit BMP085 code, replacing every instance of...
  29. Teensy library code providing i2c services

    This situation is messier than I had thought. There are at least 3 Teensy library packages providing I2C services. The AdaFruit code to control the BMP085 makes explicit use of a Wire object, and...
  30. Thanks for your quick response. I had not run...

    Thanks for your quick response.

    I had not run across any mention of Wire2 before, but it makes sense, analogous to Serial1, Serial2, etc. After a quick look, I don't see where any of the Wire<n>...
  31. apparent bug in wire library (i2c_t3) with Teensy 3.5

    I am trying to use a BMP085 pressure/temperature sensor with a Teensy 3.5. The BMP085 is on a Sparkfun board (their SEN-09694), connected through a level shifter (SparkFun BOB-11955). The code I'm...
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    multiple open files on uSD card

    I believe that at one time (perhaps in the Arduino library, long before Teensy) the SD library did not allow more than one open file at a time. I am a little confused by the various SD-related...
  33. apparent success

    @UhClem's observation seems to have done the trick. I had one hang earlier today, but I can't reproduce it. The system being redone onto Teensies runs for years at a time, so I can't yet say that I...
  34. I started by copying the code from one of the...

    I started by copying the code from one of the examples, then expanded what I thought was the result of the top-level call to try to track down my problem. Your observation suggests that I got lost...
  35. I wrote in haste; by "false alarm" I meant that...

    I wrote in haste; by "false alarm" I meant that no one should drop other projects and come running to my aid. Not yet, anyway.


    My setup already has a delay before I start organizing the SD. In...
  36. I can't say that yet. I need to do some more...

    I can't say that yet. I need to do some more testing. All I can say now is that I can demonstrate in a 10-line program that using printf instead of sprintf will be accepted by the compiler, but...
  37. false alarm; my bonehead coding error

    I was using printf instead of sprintf.
  38. I have done limited further experimentation, and...

    I have done limited further experimentation, and the SD library works only inconsistently for me. I believe that there is some sort of timing issue involved, but the library code is, as others on...
  39. problem persists with current libraries

    I am in the process of moving a big project from various hardware to Teensys. I have a Teensy 3.5 that has no trouble with the cardinfo example from the SD library, but when I use near-identical...
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