Search:

That worked thanks Paul. Should this line ever be used to configure a DAC on any teensy or should it be removed even when a Teensy 3.2 is the target?

I'm have a strange issue with using the DAC on a Teensy LC. This code works fine on a Teensy 3.2, so I'm a bit confused.. maybe I'm missing something obvious?

The code basically reads the ADC...

Hey everyone,
I'm wondering if it's possible to run a Teensy LC off of a separate 3.3V power regulator? I see that it has an onboard regulator that's actually within the microcontroller (never saw...

Hey Mark, thanks for replying.. I didn't know the code was different than the arduino map() on purpose and looking at the "more conversation" thread linked in the commented code, it looks like Paul...

After spending a night trying to debug an issue I was having, I narrowed it down the map() on my Teensy returning an incorrect value.

map(1,0, 1, 100, 0); // returns 51 on teensy, 0 on arduino.
...

So I might have found what was causing this.

My initial problem was that the Teensy in my application sometimes wouldn't turn on from a cold start (after being off for several minutes). When I...

I emailed you some large-ish files Paul that should hopefully help. I will also try some different things and report back.

It is a Mastech HY1803. I'm also able to get the problem when switching on my project power supply (LM317 +15V into the L78L05) which also has a mechanical switch before the LM317. I did notice that...

https://www.youtube.com/watch?v=IBJhrxGoAP0

Okay I made a little video of the problem happening. It happens on a cold start (after being off for minutes to hours), but the easiest way to...

Thanks Paul, I also rigged up an experiment last night using a second teensy to wait a random amount of time and turn on the first teensy and then monitor for the result. It logged thousands of...

It fails to blink or run any code. The current draw also goes down from 30mA to 20mA.

1 in every 20 is just a guess, sometimes it fails to execute twice in a row for example.



Yes. Power supply 5+ to Vin and GND to GND.

Here's some scope shots of the +5V supply and the Teensy's 3.3V supply in the 30ms after power is applied. I was hoping to see some sort of pattern indicating why the Teensy occasionally decides to...

I wonder if anyone has any experience with this problem before...

I recently noticed that my most recent Teensy 3.2 based project wasn't executing code occasionally, maybe 1 in every 20 power ups....

In this case, accurate DC voltages that change between 1-100 seconds.

Thanks for the suggestion Paul, the "complicated stuff" actually isn't complicated at all - just a comparison ( pressure.getValue() >= freezethresh ) between another ADC reading and a CONST. I will...

Hi Mark, thanks for the reply. Using a DAC is new to me, so I didn't know that the maximum error would be at that point.. that's interesting. Is "Sigma-Delta" a style/type of DAC that I should be...

Hi Jon, the ADC value is already averaged across 16 readings and is surprisingly solid (2-4 counts of noise at 16 bits!). I considered the look up table solution, but I want to make approx 20 of...

Thanks Paul, I guess it's true that from the way I tested I have no way of knowing if the error an inaccuracy in the DAC output or in the ADC reading. No pin is set to INPUT and the DAC output is the...

I finally started using the Teensy 3.2's built in DAC. Great feature, I love how easy it is to use...

My first application involves sampling a DC voltage on an ADC pin and then outputting the...

Thanks Paul, that makes sense - glad I know I'm not losing my mind! I also saved the new .hex file and will make a point of doing that on all of my projects once they are done.

I recompiled some older code (2013!) that used USBmidi.sendPitchBend and my device didn't work the way it used to.

I tracked down the problem to the function expecting a signed integer between...

Yes it is, why?

Just running some timing tests. A USB Midi pitchbend command takes 6 microseconds and a serial MIDI pitchbend command takes 1800 microseconds, so about 300 times slower. If the commands are done...

Hi David, thank you - and you're 100% right that I should just try it before I start worrying about it.

FWIW, my application is like a hakken continuum type controller (but a lot simpler) where I...

Thank you David,

Ok so basically if I do the commands sequentially then I am slowing the USB and Serial transmission down to their combined transmission rate. I'm guessing that won't be a problem,...

Hey everyone,
I'm wanting to use the MIDI library on a Teensy LC to send regular serial (DIN connector) MIDI information at the same time I'm sending the same information through a USB port using...

Hah! Thanks! Yes, I see you can't go over VDD+.3V in the datasheet. You also can't measure lower than +.256V as well.. interesting. I guess this is a good time for me to learn about clamping ...

Hi Larry, that part actually looks pretty ideal - especially if that library works without issues with the teensy.

If I'm using an external ADC then I guess I won't have access to all of the nice...

Can anyone recommend an ADC with at least 15 bits of resolution that would be decent at accurately measuring slowly changing DC voltages.. from 0-200Hz.

Would be great if the ADC could measure up...

Totally, I understand Paul. I'm not suggesting getting rid of any existing Library at this point, I'm just suggesting that in cases like this the extended functionality could have been incorporated...

Oh perfect, thank you! I didn't even see FreqMeasureMulti listed on the main page. It's on the FreqMeasure page, but easy to pass by.

Is FreqMeasureMulti rolled into teensyduino? Maybe just get...

Hey everyone,
I'd like to use my Teensy 3.2 to measure the frequency of two separate audio signals. I see that the FreqMeasure and FreqCount library are hard-coded onto a single pin.. (the LED...

Hi everyone,
I'm working on a little project that uses a Teensy 2 and display to scroll through a list of electrical component references and values. There is about 400 items in this list, and I...

Hey guys,
I want to power the Teensy 3.0 from an external source, and I'm just wondering what the maximum voltage that can go to VREGIN?

I'm also wondering what the output frequency is on the...

Thanks for this Paul,
what was the problem with USB MIDI sendProgramChange in earlier versions?

Thanks Paul, so does usb_names.h get edited directly or are there variables that I can change in the main program itself?

Hey all,
Is there an easy way to change the name that the teensy shows up as when plugged in? Instead of saying "USB Serial" or "Teensy Flight Sim Controls" I'd like it to say something else for my...

Thanks Paul, this worked great!

Thanks for the reply Paul. That's a nice feature for sure!

Unfortunately when I do that though, I only get 2.9V through AREF and not the 3.00V I was getting previously. The resistors that I'm...

Thanks JBeale, I'm seeing about 12mA going through the Vref when the teensy is powered off.

I just wanted to add some more details to this problem. I'm using an LM431 shunt regulator to get my reference voltage (in this case 3.00V). When the teensy isn't powered up, my reference voltage...

Hey all,
I'm just wondering if the ARef should be driven directly by an external reference source, or if a resistor should be used? Also what is the impedance of this input, and does it change based...

Hi All,
Just wondering.. once a project has been finalised, is there a best practice for what to do with the unconnected pins? Should they be left floating, or grounded, or something else?

Is it OK to fire off usbMIDI commands as fast at the teensy will allow it?

I did a simple program reading a few inputs and sending the appropriate usbMIDI commands, but I noticed that sometimes...

Thank you, I couldn't find information about the stability over temperature of the 3.3V regulator within the microcontroller. Looks like an external reference is the best way to go. No worries about...

Thanks for the replies Jp3141 and Paul,

Offset errors aren't a problem, the most important thing is that the scaling is accurate and linear. As for resolution, getting at least 10 bits of useful...

Thanks for the reply, that's sort of what I was suspecting. I can divide down the 0-10V as you suggested, but with the 0-5V signal having scale accurately is very important. Would that mean I should...

Hi everyone,
I'm working on a project where I need to sample three different voltages. Two are 0-10 V and one is 0-5V. Before I release the magic smoke, I just wanted to ask here if there are any...