Recent content by audiomath

Looking at the chart with fresher eyes, it appears that RTS/CTS can be implemented without using XBAR : Teensy 4.0 Serial3, CTS Pin 19 Serial5, CTS Pin 35 Teensy 4.1 Serial3, CTS Pin 19 Serial5, CTS Pin 43 Serial8 CTS Pin 50 Am I reading this right? Thanks!

I'm sure this is a well-worn subject to some of you around here, but it's new to me. If I want to use RTS/CTS handshaking between two Teensy 4.1s, I need to invert the incoming CTS before it gets to the assigned pin? So it would seem, since Teensy 4.0 and 4.1 support only XBAR pins for CTS and...

Thanks for the reply. It was short ESD spikes that I was thinking of. If the spike gets swamped by the regulator filter, I suppose all would be well. I need to spend some time looking at industry literature that describes the typical ESD spike. It's been long enough that don't remember much more...

I found this thread while thinking about this very thing last night. Say I use BAT54-S packages across a batch of GPIOs, with the high side tied to the 3.3V rail of a Teensy 4.1 . Looking at the schematic, that probably isn't the best thing to do. The 3.3V regulator probably isn't designed to...

Which is what I should have done. I have the rail on the PCA, but didn't think about it until after-the-fact.

I would like to use the USB Host port on a Teensy 4.1 to communicate with a CDC USB Device. I understand the USBHost_t36 library exists to enable this. Since I'm running the Teensy 4.1 from the 3.3V rail on my PCA, the USB Power trace is cut and there is no 5V supplied to VIN. What would be the...

Thanks for the reply. After giving it some more thought, please don't go to any additional effort on my account. I've decided to add additional logic required to make it a stand-alone solution. Not because I don't "trust" software, but because future applications might employ a much less...

Hello, I have a DIY MOSFET H Bridge that requires opposite-phase signals to drive a motor "forward" or "reverse". That's easily accomplished with two IO pins on the Teensy 4.0 . What I'm hoping to find is an easy way to generate PWM on two pins, exactly 180 degrees out of phase - and have...

I'm working on a hobby design in my spare time that uses a Teensy 4.0 in a EMI/RF sensitive application. With regard to *unused* pins, would you: (1) Tie them directly to ground (and set them to OUTPUT and LOW in the startup code) (2) Tie them to ground through a series resistance (3) Leave...

Yes, looking for symmetry in the FFT magnitudes will work, but I'm not sure how well it will work without at least one strong signal in the bandpass. I'll take a look at PCM5102, thanks! This also has me wondering if the PCM3060 would work. I licensed a DSP "engine" to a manufacturer who uses...

"So, for an SDR, why not try the Teensy 4.0 or 4.1 with the ADC PCM1808a module? The latter is available for a few dollars at Ebay or Aliexpress." I would consider that, thanks. That part is only an ADC, though. Not useful for a transceiver, unless I use something else for a DAC. Using two...

Thanks! That was a quick/clever repro. 1 sample @ 44110 is 22.676us. If it's consistent then the right channel is 1 sample late when this occurs. Now the question becomes can anything be done about it... Derek mentions in his PDF that the issue has been identified on different ARMs. That may...

Sorry, I thought it was a widely known issue. Unfortunately, I don't have a way for any Teensy dev to duplicate this without the SDR hardware. In a nutshell, however it seems that when I2S starts up for recording, the L/R sample order appears to be "random". That wouldn't matter in the slightest...

Hi folks, Does the Teensy 4 and current audio lib still have the startup unpredictable I2S sample alignment issue? I have a few new projects lined up for Teensy 4, and since I'll be there I thought I'd play with yet another SDR library implementation. Thanks! --jim

Hi Rob, The git repository has a description of the library, but what caught my eye was your comment about the Si5351. If you ever get back to it, the trick to glitchless tuning is to only program the PLL's at startup and when a large excursion would require it, like a band change. There's...