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Thread: Teensy does not start up from cold boot

  1. #1
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    Teensy does not start up from cold boot

    I have tried the suggested delay (10 seconds) at start up to give time for everything to initialise, however I can not get it to cold start. I have done this for blink and it doesn't seem to work even on blink. I have the octows2811 board from pjrc https://www.pjrc.com/teensy/td_libs_OctoWS2811.html connected as well as
    prjc Ethernet board https://www.pjrc.com/teensy/td_libs_Ethernet.html configured as suggested in the respective pages. This is a teensy 3.6 running at 180mhz, usb type: serial and optimimser : faster
    Code:
    /* LED Blink, Teensyduino Tutorial #1
       http://www.pjrc.com/teensy/tutorial.html
     
       This example code is in the public domain.
    */
    
    // Teensy 2.0 has the LED on pin 11
    // Teensy++ 2.0 has the LED on pin 6
    // Teensy 3.x / Teensy LC have the LED on pin 13
    const int ledPin = 13;
    
    // the setup() method runs once, when the sketch starts
    
    void setup(){
      delay(10000);
      // initialize the digital pin as an output.
      pinMode(ledPin, OUTPUT);
    }
    
    // the loop() methor runs over and over again,
    // as long as the board has power
    
    void loop() {
      digitalWrite(ledPin, HIGH);   // set the LED on
      delay(1000);                  // wait for a second
      digitalWrite(ledPin, LOW);    // set the LED off
      delay(1000);                  // wait for a second
    }

  2. #2
    Senior Member PaulStoffregen's Avatar
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    Maybe test without that 10 second delay in setup().

    I know 10 seconds is way past my attention span to see whether any electronic thing is still working!

  3. #3
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    So I have tried it without the sleep. and it still doesn't work.

  4. #4
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    The Ethernet board is probably interfering with the led pin. Pin 13 is the LED pin but it is also the SCK pin for SPI which is used by the Ethernet board.
    Try connecting a LED to a free pin (with a resistor of, say, 330ohms in series) and use that instead of pin 13.
    Or try removing the Ethernet board temporarily.

    Pete

  5. #5
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    If I power the octo board first then putting in the teensy it works. Leaving both of them connected during a cold start doesn't let it run any code. We power the whole system with 5V from the octoboard.

  6. #6
    Senior Member PaulStoffregen's Avatar
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    Quote Originally Posted by inuradz View Post
    We power the whole system with 5V from the octoboard.
    Which version of Teensyduino are you using? In Arduino, click Help > About to check.

    Version 1.46 fixed for a startup problem that used to happen with Teensy 3.6 when used with an external power supply having a relatively slow soft-start behavior. If you're using an older version, and if this is all being powered by an external supply, maybe you're seeing that problem?

  7. #7
    Junior Member MorganS's Avatar
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    Thanks to this post, I've just updated to V1.46 and I'm still seeing the problem. I have two Tensy 3.6's soldered to a single board with a 3.3V power supply to the 'primary' 3.3V pins on each board. Depending on the exact power-up ramp, one or both may not start. I started with a Pololu buck converter which has a really smooth ramp from zero to 3.3V over 3ms but it's doing it with my bench supply too.

    I'm only running Blink on each board for testing. The two boards have Serial6 connected between them but otherwise they are independent. There's very little other circuitry on the board; just three RS232 converter chips. There's 3 x 2.2uF decoupling caps on the 3.3V rail.

    I have a lot of other Teensy 3.6 using similar Pololu power supplies with no problem but all of them are 5V supplies to the Vin pin. This is the first board I've made using the 3.3V pin as input.

    Arduino 1.8.8 on Windows, if it helps.
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  8. #8
    Senior Member+ defragster's Avatar
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    @MorganS : Does this seem related : Issue-when-connecting-two-teensy-3-6-via-serial-pins

    Post #2 has a sketch on that thread - seems tha same as version in post #10 ZIP - then the later posts with notes where I got failure to start T_3.6's

  9. #9
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    Quote Originally Posted by defragster View Post
    @MorganS : Does this seem related : Issue-when-connecting-two-teensy-3-6-via-serial-pins

    Post #2 has a sketch on that thread - seems tha same as version in post #10 ZIP - then the later posts with notes where I got failure to start T_3.6's
    @defragster, what is the suggested solution?
    I remember myself that once or twice, when I plugged in a teensy (3.6?), it automatically reprogrammed.
    May it be that the initial speed negotiation put the teensy into the very low-speed mode where teensy goes into reprogram mode?
    Also, could the yield() function, which reacts to serial ports, be interfering with USB - serial setup negotiations and result the teensy ending up in reprogram mode ?

  10. #10
    Senior Member+ defragster's Avatar
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    Quote Originally Posted by WMXZ View Post
    @defragster, what is the suggested solution?
    I remember myself that once or twice, when I plugged in a teensy (3.6?), it automatically reprogrammed.
    May it be that the initial speed negotiation put the teensy into the very low-speed mode where teensy goes into reprogram mode?
    Also, could the yield() function, which reacts to serial ports, be interfering with USB - serial setup negotiations and result the teensy ending up in reprogram mode ?
    Was suggesting using the sketch linked on that thread (change to Serial6 if/as needed} to see if it causes the same behavior as related on that other thread to gather more info.

    The post by MorganS doesn't have code - but seems to describe what was done in that sketch:: { Serial6 linked } and what seemed to be similar behavior of 'one or both may not start'.

    If it repros: Would be interesting to try TD prior to V1.46 if so and see if the change in startup brought this on - it seems I would have seen it {using since Beta of T_3.6} as the situation seems like that I posted recently on T4 beta thread.

  11. #11
    Senior Member PaulStoffregen's Avatar
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    Quote Originally Posted by MorganS View Post
    I've just updated to V1.46 and I'm still seeing the problem.
    .....
    Depending on the exact power-up ramp, one or both may not start.
    Very strange. Could you double check the update really worked? In Arduino, click Help > About (or Arduino > About if using a Mac). It will show the version of Arduino and Teensyduino.

    After checking the version, please upload again to *both* boards. Even if you have upgraded on the PC side, the slow startup fix only takes effect after you upload a new program to the Teensy. Maybe also change the blink speed, so you can visually check Teensy really is running a new program built by the updated version of Teensyduino. If Teensy happens to be still running code made by an old version of Teensyduino, it'll still get stuck no matter what you're running on your computer.

  12. #12
    Junior Member MorganS's Avatar
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    Quote Originally Posted by defragster View Post
    @MorganS : Does this seem related : Issue-when-connecting-two-teensy-3-6-via-serial-pins

    Post #2 has a sketch on that thread - seems tha same as version in post #10 ZIP - then the later posts with notes where I got failure to start T_3.6's
    It may be related. I came across that one first in my searching, before I found Paul's comment that directed me to look at V1.46

    @Paul, yes definitely, I checked Help->About. I have two laptops and only updated one, so I could go back and forth, but didn't pass the first hurdle of solving the problem. Yes, I changed the blink speed with each upload to check it was a new upload. Can you share any more details on what actually was changed or what was it about the power supplies you tested that seemed to trigger the original problem?

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