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Thread: Teensy3.1 Occasionally unresponsive

  1. #1
    Junior Member
    Join Date
    Jan 2018

    Teensy3.1 Occasionally unresponsive

    My Teensy 3.1 (T3.1) loses serial connection and also non-functional (but recoverable); Could use help tot figure out why.
    In this un-responsive mode, it no longer appears connected (under Port) and devices attached to it (2.2" TFT ILI9341) goes blank.

    Recovery : (Thanks Paul, picked this up from a previous "Teensy dead thread") Disconnect USB cable, hold Reset button, reconnect USB cable, wait 15sec release USB button; then load "Blinky"; then upload program again (code below)
    After recovery, the code works; but would feel much better knowing why the T3.1 went un.responsive.

    This behaviour is a recent thing, since I moved the T3.1 from the breadboard to a prototype board.
    On the breadboard, the program was stable, and operated indefinitely.
    On the breadboard mu connections were: CS=D10, DC=D9; MOSI=D11, MISO=D12, SCK=D13, RESET=Vdd(3.3v), RLED=100ohm from 3.3v
    In going to the porto board, I did make a few small change,
    CS=D15, DC=D10, others remained the same MOSI=D11, MISO=D12, SCK=D13 RESET=Vdd, RLED=82ohm from 3.3v
    HW wise, I have double-checked connections; all seem fine (evidenced by the board working after recovery)
    I do not see any component on the T3.1 board, or the 82ohm resistor, or anything on the TFT board getting hot.

    Grateful for any thoughts and suggestions..



    PS. I am relatively new to the Teensy devices, and still learning..

    Full Code:#include "ILI9341_t3.h" //TFT library with Teensy3+
    #include <SPI.h>
    #include <Wire.h>
    #include "font_Arial.h"

    #define TFT_CS 15 //<<<<<<====NOTE: FOR INTEGRATED BOARD WITH T3 AND 2.2TFT
    #define TFT_DC 10 //<<<<<<====NOTE: FOR INTEGRATED BOARD WITH T3 AND 2.2TFT
    #define TFT_MOSI 11 //defaulat MOSI
    #define TFT_MISO 12 //default MISO
    #define TFT_SCK 13 //default SCK
    #define TFT_RST 255 //tied to 3.3v

    #define TFT_GREY 0x5AEB

    ILI9341_t3 tft=ILI9341_t3(TFT_CS, TFT_DC, TFT_RST, TFT_MOSI, TFT_SCK, TFT_MISO);

    #define CMPS11_ADDRESS 0x60 // Address of CMPS11 shifted right one bit for arduino wire library
    #define ANGLE_8 1 // Register to read 8bit angle from

    #define aXneutral 160 //aircraft Xneutral = center of box
    #define aYneutral 150 //aircrat Yneutral = cener of box
    #define aYoffset 0 //aircraft Yoffset to compensate for installation
    #define aXrange 90 //box is 180 wide
    #define aYrange 90 //box is 180 tall
    #define aRadius 8 //aircraft fuselage size
    #define tLen 30 //aircraft tail size
    #define wLen 50 //aircraft wing size
    #define maxUPpitch 45
    #define maxDNpitch -45
    #define screenColor ILI9341_BLACK
    #define headingTxtColor ILI9341_YELLOW
    #define headingBakColor ILI9341_BLACK
    #define headingBoxColor ILI9341_YELLOW
    #define headingFont 6
    #define headingTxtSize 1
    #define boxFillColor ILI9341_NAVY
    #define boxBoxColor ILI9341_WHITE
    #define boxXhairColor ILI9341_DARKGREEN
    #define boxBankMarkerColor ILI9341_WHITE
    #define boxPitchMarkerColor ILI9341_WHITE
    #define boxPitchLineColor ILI9341_DARKGREEN
    #define boxAircraftColor ILI9341_WHITE

    int pitch, roll;//pitch and roll: valid range are +/-85degrees
    int newHeading, oldHeading;//heading
    int fontValue=6;//heading text font
    // screen positions and increments for heading value display
    int hYpos=10, hXpos=115, hXinc=30;//heading text position and increment
    // aircraft display box start and end values
    int aXstart=aXneutral-aXrange, aXend=aXneutral+aXrange;
    int aYstart=aYneutral-aYrange, aYend=aYneutral+aYrange;
    int oldAYpos= 150; //=(71+239)/2 aircraft dot position
    int WX1=0, WX2=0, WY1=0, WY2=0;//wing line position
    int TX1=0, TX2=0, TY1=0, TY2=0;//tail line position
    //roll angle marker coord -inside, outside for R1=62, R2=70/80: angles 0->180deg, 15deg increments
    int mX1[]={62,60,54,44,31,16,0,-16,-31,-44,-54,-60,-62}, mX2[]={80,68,69,49,40,18,0,-18,-40,-49,-69,-68,-80};//marker xcoord for 15, 30, 45, 60deg, R=45, 60
    int mY1[]={0,16,31,44,54,60,62,60,54,44,31,16,0}, mY2[]={0,18,40,49,69, 68,80,68,69,49,40,19,0};//marker ycoord for 15, 30, 45, 60deg, R=45, 60
    //pitch angle marker coordinates outside the Attitude box
    int pMx[]={10,5,10,5,10}, pMy[]={0,18,36,54, 72, 90};
    // marker coordinates from MarkerCoordinates Spreadhseet

    void setup()
    //tft.fillRect(aXstart,aYstart, aXrange*2,aYrange*2, boxFillColor); //attitude box
    //Attutude Box
    tft.fillRect(aXstart, aYstart, aXrange*2, aYrange, ILI9341_BLUE); //sky half
    tft.fillRect(aXstart, aYneutral, aXrange*2, aYrange, ILI9341_MAROON); //ground half
    tft.drawRect(aXstart, aYstart, aXrange*2, aYrange*2, boxBoxColor); //draw Outline
    for(int i=0; i<6; i++){ //draw pitch angle markers
    tft.drawLine(aXstart-pMx[i],aYneutral+pMy[i],aXstart, aYneutral+pMy[i], boxPitchMarkerColor);
    tft.drawLine(aXstart-pMx[i],aYneutral-pMy[i],aXstart, aYneutral-pMy[i], boxPitchMarkerColor);
    tft.drawLine(aXend+pMx[i],aYneutral+pMy[i],aXend, aYneutral+pMy[i], boxPitchMarkerColor);
    tft.drawLine(aXend+pMx[i],aYneutral-pMy[i],aXend, aYneutral-pMy[i], boxPitchMarkerColor);
    tft.setTextColor(headingTxtColor, headingBakColor); //heading text color
    tft.drawRect(100, 5, 120, 53, headingBoxColor); //box over heading
    for(int i=0; i<13; i++){
    //Serial.begin(9600); //Debug only

    void loop()
    Wire.beginTransmission(CMPS11_ADDRESS); //starts communication with CMPS11
    Wire.write(ANGLE_8); //Sends the register we wish to start reading from
    // Request 5 bytes from the CMPS11: byteHeading, wordHeading, bytePitch, byteRoll
    Wire.requestFrom(CMPS11_ADDRESS, 5);
    while(Wire.available() < 5);// Wait for all bytes to come back
    newHeading =;//read byteHeading heading value and discard
    newHeading =;//read high byte of wordHeading value
    newHeading = (newHeading<<=8);//shift high byte by 8bits, then read and add lower byte
    pitch =;//read bytePitch
    roll =;//read byteRoll
    newHeading/=10; //Remove decimal value
    //reverse heading direction for board header at aircraft tail end---------
    if(newHeading<0) newHeading+=360;
    if(pitch>127) pitch-=256;
    if(roll>127) roll-=256;
    //limit pitch value to maxPitch for better pitch display sensitivity
    if(pitch>maxUPpitch) pitch=maxUPpitch;
    else if(pitch<maxDNpitch) pitch=maxDNpitch;
    //Serial.print("Pitch="); Serial.print(pitch); //Debug only
    //Serial.print(" : Roll="); Serial.print(roll); //Debug only
    //Serial.print(" : Heading="); Serial.println(newHeading); //Debug only
    printHeading();//update heading display value
    drawAircraft(roll, pitch);//update pitch/roll display

    delay(100); // update approx 10 times per second

    void drawAircraft(int rValue, int pValue){ //For T3, changed to int from char; fixed ISSUE in _000
    int newYneutral=aYoffset+map(pValue, maxDNpitch, maxUPpitch, aYend, aYstart);
    int aYdip= (int)((float)aXrange*sin((float)rValue*0.0174));
    int aY1=newYneutral-aYdip, aY2=newYneutral+aYdip;
    if(aY1>aY2){ //aY1 is left side, aY2 is right side
    tft.fillRect(aXstart, aYstart, aXrange*2, (aY2-aYstart), ILI9341_BLUE);//fill sky to higherY on screen
    tft.fillRect(aXstart, aY1, aXrange*2, (aYend-aY1), ILI9341_MAROON);//fill ground from lower Y to bottom
    tft.fillTriangle(aXstart, aY1, aXend, aY1, aXend, aY2, ILI9341_MAROON);//fill lower triangle with ground
    tft.fillTriangle(aXstart, aY2, aXstart, aY1, aXend,aY2, ILI9341_BLUE);//fill upper triangle with sky
    else{ //roll Left -works well
    tft.fillRect(aXstart, aYstart, aXrange*2, (aY1-aYstart), ILI9341_BLUE);//fill sky to higher Y on screen
    tft.fillRect(aXstart, aY2, aXrange*2, (aYend-aY2), ILI9341_MAROON);//fill ground from lower Y to bottom
    tft.fillTriangle(aXstart, aY1, aXend, aY1, aXend, aY2, ILI9341_BLUE);//fill upper triangle with Sky
    tft.fillTriangle(aXstart, aY1, aXstart, aY2, aXend, aY2, ILI9341_MAROON);//fill lower triangle with Ground
    //Draw Aircraft
    tft.fillRoundRect(aXneutral-wLen, aYneutral, wLen*2, 4, 2, ILI9341_WHITE); //draw Wings
    tft.fillRoundRect(aXneutral-2, (aYneutral-tLen), 4, tLen, 2, ILI9341_WHITE); //draw Tail
    tft.fillCircle(aXneutral, aYneutral, aRadius, ILI9341_WHITE); //draw Fuselage
    //Draw Bank Markers
    for(int i=0; i<13; i++){
    tft.drawLine(mX1[i], mY1[i], mX2[i], mY2[i], ILI9341_WHITE);//Flickers jsut redrawing! Why?

    void printHeading(){
    int i, decade, nHvalue=newHeading, oHvalue=oldHeading, x=hXpos, y=hYpos;

    // Check individual digits; only if changed then erase old/print new; eliminates flicker
    for(i=0, decade=100; i<3; i++){
    if((nHvalue/decade) != (oHvalue/decade)){
    tft.setCursor(x, y);
    tft.setCursor(x, y);
    nHvalue%=decade; oHvalue%=decade;
    decade/=10; x+=hXinc;
    tft.drawRect(100, 5, 120, 53, headingBoxColor); //box over heading


  2. #2
    Junior Member
    Join Date
    Jan 2018
    Adding some more details, occasionally the program on the T3.1 now hangs.
    When the program is hung, the T3.1 no longer appears in Tools>Port

    Could the choice of CS(D15) and DC(D10) have something to do with the in-stability?
    (that and the RLED are the only change that I can think of)

    One additional note: When I re-upload the code (modified or not), the upload now seems to take much longer than previously on the breadboard.

    Any help much appreciated!

  3. #3
    Senior Member+ defragster's Avatar
    Join Date
    Feb 2015
    Paul could say - but I only know the T_3.5 and T_3.6 to have been programmed with the 15 second recovery process. Never saw upload speed change or seem long.

    Code would be much easier to read if post was edited to select the code block and then hit the "#" hash on the post edit toolbar to enclose in the [C0DE] /... [/C0DE] block.

    Most often hangs stopping USB are from trashing memory. Odd thing I see is the 'while(Wire.available() < 5);' that will show teensy to be unresponsive if the i2c gets hosed - though that shouldn't stop the USB from facilitating new upload - unless that code has gone badly. A timeout on that followed by an error note might indicate a problem - or just turn on LED_BUILTIN before and off after to know it isn't stuck on that.

  4. #4
    Junior Member
    Join Date
    Jan 2018
    Update: I moved CS->D10 and DC->D9 on the protoboard (like I had on breadboard) and operation appears to be stable.
    Will run it overnight to see if still happy in the morning..

    @defragster: Thanks! I tried other means of recovery (e.g. re-boot computer, hold button and connect cable) -did not make T3 appear on Tools>Port. But with the 15sec procedure , the T3.1 programmed ok.
    and thanks for the pointer on including code; my first post.. learning..

    So, am I understanding D10 <-> CS are exclusive?


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