trill teensy oddity

lokki

ok, i have a really strange problem with a trill craft and a teensy lc.

i am developing a patch on the teensy and if i upload it to the teensy the sketch and the trill work fine, but whenever i unplug the teensy and replug it to the mac, the trill sensor no longer works (setup completes and there are no errors generated, so i assume the trill is correctly seen by the teensy)

if i send some midi to the mac from the teensy in the loop function, non related to the trill, it works even after a replug, so i know the sketch is running...

any ideas?

lokki

ok, upon further investigation, there seems to be something wrong with the EVT pin, i think it is not correctly set from the teensy setup routine when teensy boots up, and only when i upload program. probably because in the latter case the trill craft always has power even when i upload a new sketch to teensy, while when i disconnect the power cuts and somehow the craft falls into a state where it does not accept the trillSensor.setAutoScanInterval(1); delay(Trill::interCommandDelay);

command. i changed the craft-print example program to only read data when the EVT pin is high and it now also refuses to work after a unplug/replug of the teensy. will investigate further

lokki

and boom, that was an easy fix...

simply changing the order of the trill settings in setup makes it work on reboot!

so, this does only work on upload, but not on reboot:

     trillSensor.setAutoScanInterval(1);
    delay(Trill::interCommandDelay);
     trillSensor.setScanSettings(0, 9);   
    delay(Trill::interCommandDelay);
    trillSensor.setPrescaler(1);   
   delay(Trill::interCommandDelay);
    trillSensor.setMode(Trill::DIFF);
    delay(Trill::interCommandDelay);
   trillSensor.setNoiseThreshold(8);
  delay(Trill::interCommandDelay);
trillSensor.setAutoScanInterval(1);
    delay(Trill::interCommandDelay);

while this works all the time, even after unplug/replug:

     trillSensor.setAutoScanInterval(1);
    delay(Trill::interCommandDelay);
     trillSensor.setScanSettings(0, 9);   
    delay(Trill::interCommandDelay);
    trillSensor.setPrescaler(1);   
   delay(Trill::interCommandDelay);
    trillSensor.setMode(Trill::DIFF);
    delay(Trill::interCommandDelay);
   trillSensor.setNoiseThreshold(8);
  delay(Trill::interCommandDelay);

probably either a timing issue (although i tried inserting larger delays at different points in the setup) or an incompatibility between two of the settings, one overriding the other.

or is this expected, because i did something wrong with the setup procedure?

giuliomoro

The general issue you are seeing, where the Trill device exhibits a different behaviour between first and successive runs is probably due to the fact that unless you use the RESET pin or power-cycle the device, the device will preserve its internal state when you re-upload your sketch. The order in which you set the parameters is important as some are interconnected. In practice you may find that the order in which you set parameters is such that it doesn't quite work upon the first run because they are in the "wrong" order, but when you run it again it works because the combination of setting the settings the first and the second time - with the state preserved in between the two - results in a working combination.

Now, if the only settings you are setting are the ones you reported here, then I don't see why the device would behave differently between the first and the second option. One thing I see that is missing - however - is that you should be calling updateBaseline() after updating the scan settings or prescaler if you are using the DIFF mode. If you don't do this, the sensor may look like it is not working (because the DIFF reading returns all zeros and the EVT pin doesn't get toggled).

lokki

yes those were the only settings in the sketch. i will try the updateBaseline()...

lokki

ok, with updateBaseline() in place both work after an unplug:

trillSensor.setAutoScanInterval(1);
    delay(Trill::interCommandDelay);
    trillSensor.updateBaseline();
    delay(Trill::interCommandDelay);
     trillSensor.setScanSettings(0, 9);   
    delay(Trill::interCommandDelay);
    trillSensor.setPrescaler(1); 
     delay(Trill::interCommandDelay);  
    trillSensor.updateBaseline();
    delay(Trill::interCommandDelay);
    trillSensor.setMode(Trill::DIFF);
    delay(Trill::interCommandDelay);
   trillSensor.setNoiseThreshold(8);
  delay(Trill::interCommandDelay);

and


     trillSensor.setScanSettings(0, 9);   
    delay(Trill::interCommandDelay);
    trillSensor.setPrescaler(1); 
     delay(Trill::interCommandDelay);  
    trillSensor.updateBaseline();
    delay(Trill::interCommandDelay);
    trillSensor.setMode(Trill::DIFF);
    delay(Trill::interCommandDelay);
   trillSensor.setNoiseThreshold(8);
  delay(Trill::interCommandDelay);
trillSensor.setAutoScanInterval(1);
    delay(Trill::interCommandDelay);
    trillSensor.updateBaseline();
    delay(Trill::interCommandDelay);

thanks!

giuliomoro

great. You can use a single updateBaseline() at the end: no need to have one after each scan-related command.