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OK 128, no worries. Suppose you allow the pair R1A and R1B to be not quite equal anymore. In fact, suppose they're the two legs of a potentiometer, and the ADC node is the wiper (close to the middle, but variable). Tweaking the ratio R1A:R1B a little will change the DC bias point a bit, no...

Good, you got it. Now think, what causes that little offset? How might you fix it?

Good catch, hadn't had my coffee! So you did check my math, awesome ;^) I edited #4. Not sure how to draw a readable picture in here, the editor mangles ascii graphics. Let's try a cell phone picture. First example A (where R1 ~ 137k, and R2 ~ 863k) and then, to fix the DC offset...

Hi 128- Rather than jumping straight into op amps, why not start with your requirements and work up to what you need? Sounds like you want to match a range of ±12V (24V total span) to the 0-3.3V range of the ADC. As Paul suggests, you may also want your circuit to work with a standard 10x...

Very nice idea! Although I wonder if "economic" is quite the right word... maybe "serene?" (BTW the blinking is also much less obtrusive since you folks helped me speed up the pulses, thanks for that help as well!) Advance, or retreat? ;^) I'd been thinking of a GPS module... but you're...

Thanks Paul, that indeed did the trick, in particular this line CORE_PIN14_CONFIG = PORT_PCR_MUX(1); // no slew rate limit after the pinMode() declaration. Doing this, I get nice 10ns pulses at 20MHz. I suppose this strange throttling action is some kind of EMC measure? Very annoying. On...

Greetings- I'd like to toggle a pin a bit faster than the ~ 2 MHz I get with successive digitalWrite() calls in a for() loop, to get a specific-length burst out quickly. I stumbled on the function digitalWriteFast() in some other threads, and it compiles without warnings, but it doesn't...

Here's a very simple clock display idea, if you already have a surplus digital counter. I like Nixie tube counters, like this HP5216A. It has a "totalize" function where it just counts input transitions, and also a TTL "reset" input on the back. Pull reset low briefly to clear the counter, then...

These fonts do look amazing on my scope, it's incredible how Hershey digitized them in such extraordinary detail. That said, I can't see much of practical utility beyond the few Greek and math characters that might come up on a test instrument display; so (for me) it's hardly a priority to...

Teensyduino 1.40 Arduino 1.8.2

Magnificent, thank you neurofun!! (In the meantime I whipped up a comparable script in Matlab, but that will be useless to most readers here.) Re: application at hand, many of the characters have hundreds of vertices; this will challenge the Teensy DAC and scope to keep up without...

Trying to output quadrature test waveforms, I found that waveform.phase(90) produces the correct result for sine and square waveforms but incorrectly renders a 45 degree phase shift for triangle and ramp waveforms. T 3.2 with audio shield, Arduino 1.8.2. Example code to reproduce this issue...

Forgive awakening an old post, but seems best to keep everything on this topic where it can be found, even if it's beating a long-dead horse. I just got a couple of these TJCTM24028-SPI displays from PJRC and it's all "new to me." First, I was disappointed in the brightness: connected as...

EDIT: demo video is now up for preview. Comments/suggestions welcome.

The simplex font library, from Paul Bourke's site. I'd be interested if anyone could help me translate the higher codes, particularly math symbols and greek letters, into similar format; the algorithm sounds straightforward but I don't yet have the skills. #ifndef _hershey_simplex_h #define...

Finally got round to this, very good results on a 3.5. I put a demo here on YouTube. Nothing but the Teensy and a couple scope probes into a Tek 2213A (60 MHz analog, 14 kV PDA; ca. 1985 or so). Jerkiness visible in the line test appears to be aliasing by the video camera, I don't see that...

Maybe this has been covered, pretty basic stuff, but in case it helps someone: My "Oscilloscope Music" player toy delivers various CW audio test waveforms from the audio library AudioSynthWaveform object if an audio file is not supplied. However, waveforms with sharp transitions (e.g...

As a fan of Teensy and the amazing engineer/artist/composer Jeroboam Fenderson, and also a collector of antique oscilloscopes, I was inspired (compelled?) to build this simple stereo player / scope XY display driver. A T3.2 with audio shield and SparkFun TeensyView OLED display cycles...

Just wondering if anyone has worked out an application like this https://www.nycresistor.com/2012/09/03/vector-display/ using the built-in DAC hardware on the 3.5 or 3.6. I'm sneaking up on a vector CRT display emulator for legacy (boat anchor) test equipment, e.g., HP 1345A. Any...

Thanks, much appreciated; this post did come up in my searches, but the context was not clear. What is a K66? Is the "beta test" title indicating that this function is not yet officially implemented? Indeed, such register manipulation would probably be beyond my experience level; a c-type...

Newb here, can anyone offer a link showing how to call the hardware RNG in the 3.5 and 3.6? Depending on speed I'd either default to it or just use it once to seed rand() by srand(). Tx, mike

Thanks Paul! It remains unclear why the board was initially invisible to IDA and teensy.app (irrespective of serial). Only explanation I can think of is an intermittent cable, or perhaps more spooky El Capitan nonsense.* Resetting Tools > USB Type > Raw HID made board info available...

RESOLVED (tx) MacBook Pro, OSX 10.11.6, Arduino IDE 1.8.2, teensyduino 1.3.6 (installed today); Hi- New to this product/forum, just received my 3.5 today and uploaded Teensyduino.app as well as the standalone teensy.app. IDE does not offer it in the port menu. Direct load using the...