Connecting a motor direct to pin 8 of the Teensy? That doesn't sound safe, back EMF, burn out the pin through overcurrent, ESD through handling the motor - several ways this could be bad news.
Yes, its an unmodified Audio adapter D that I've had for a while but only just soldered headers too and started using. Since the QA403 has high input impedance the caps distortion should be relatively low.
I hope they are C0G/NP0 type...
Yes I think 80kHz for the measurement bandwidth - which may be a little unfair.
Well you could measure it directly by sending to USB and capturing the raw data without using any DAC for a definitive answer - the SGTL DAC is clearly dominating...
I took the Waveforms Audio example, set the frequencies to 1000Hz, wave type to sine, and maxed the levels with
sgtl5000_1.lineInLevel(0);
sgtl5000_1.lineOutLevel(13);
And looked at the line outputs with my QA403 audio analyzer:
Which...
Yes, you are missing SYS_FS and MCLK_FREQ, also in CHIP_CLK_CTRL which sets the clock, this in combination with the RATE_MODE determines the sample rate, see datasheet table 18. I think you'll need to reduce the MCLK frequency sent to the chip...
Well the schematic does not show the power supply arrangements or decoupling for one thing. Where does the +/-15V come from for instance?
I do note the TL072 trying to drive 470nF through 16 ohms - likely to oscillate, opamps can't drive heavy...
The T4 is absolutely _not_ 5V tolerant, 3.3V is the limit for all pins - this is clearly stated in the data for the device. You require level converters to talk to a 5V chip (if you haven't fried the T4 already).
The T4 can switch extremely fast, 10ns or something like that, even digitalWrite is very fast (though not quite that fast!). There is a delayNanoseconds() call which can be useful on the T4.
please describe in more detail how you are powering them than
Part number, current rating, that sort of detail is essential. A diagram is helpful so we are on the same page.
uint16_t r = (sin(t + 60.0 * 0.0) * max + max);
uint16_t g = (sin(t + 60.0 * 1.0) * max + max);
uint16_t b = (sin(t + 60.0 * 2.0) * max + max);
Suggests an assumption that sin takes degrees rather than radians, so there are...
Servos take a lot of current, please describe in more detail how you are powering them, the current ratings of the parts etc. Also which servos are you using?
See this thread:
https://forum.pjrc.com/index.php?threads/envelope-detector-and-vca-with-teensys-audio-library.29579/
abs means absolute value as in envelope detection.
Hot-plugging requires a connector where ground & power connects before data, as in a USB plug. Otherwise in your case you can get a situation where only the 12V and a data line are connected, putting 12V through the Teensy.
Alternatively add...
The FFT relies on gathering 8 consecutive audio blocks and then gets to work. Without 8 distinct blocks it will have wrap-around and mess up audio block allocation for the whole audio chain I believe.
The length of the delay line is limited to 536 entries:
int16_t buffer[536]; // TODO: dynamically use audio memory blocks
Which corresponds to a round-trip delay of 24.3ms, which is 41.13Hz
It is interference, completely expected unless you properly shield the components - if you look at every radio-transmitter you'll see the design involves various compartments all individually shielded (Faraday cage). You need to do the same, put...
That RFD868 module seems to output upto "30dB", which I take to mean +30dBm (i.e. one watt). Yes that's going to kill nearby circuitry easily if not shielded properly. Typical dipole antenna voltages for 1W might be upto 50Vrms at the tips, so...
Hi all.
We built a school playground using Teensy 4.
Instagram post
Interface is a Teensy 4 with 3x mpr121 and rs485. We have another Teensy 4 to process the commands, send midi data, play music (Teensy Audio Shield), control relays and LEDs...
Start with one. The DRV8833 datasheets how to use it in fast-decay and slow-decay modes.
There are encoder libraries for standard quadrature AB and ABZ encoders.
That's a coupling capacitor. The 2.22uF below it is the decoupling cap. The connector is DC-linked to MICBIAS output, which is why an external coupling capacitor needs to be used if the source doesn't handle a DC-offset.
You'll need a DC-blocking cap as the microphone pads are designed for an electret capsule. I'm not sure what you mean by a GBF, gain before feedback is a measurement.
Plain crystals are never temperature compensated, they are just a sliver of quartz, only crystal oscillators, aka TCXO, have compensation. The microcontroller datasheet will probably have the specifications for the RTC XTAL.
74HCxx family at 3.3V can allegedly clock upto about 40 or 50MHz, though I would play safe and aim for 30MHz max. 74LVC595 would be considerable faster as its designed for 3.3V.
No, use a resistor, or you'll fry the LED or the Teensy. The absolute maximum ratings are just that. Exceed them and degradation and failure can happen.
Why not consider a neopixel which takes one control signal and does the PWM for you?
#include's happen at compile time. You are asking for something like dynamically linked runtime libraries, loaded from a filesystem at runtime (SDcard?), or something like code overlays.
Do you actually have a problem with running out of code...
Remember there's also the time to de-glitch the input and process the vectored interrupt, not every part of the chip is clocked at the full 600MHz either. Anyway 72 cycles is only 120ns at 600MHz, which is very fast for an ISR response. Beyond...
No, it has to save all the registers it uses to stack which is many cycles. When the interrupt occurs it has no knowledge of which registers are live or not so it has to save all the ones it will clobber, not just the callee-save set like a...
Its been a while since I used this, it might be a lack of memory (only the setSampleCount() function currently reports back a success value, the setFIRCoefficients() call blindly ignores if setSampleCount() fails - that needs fixing really, both...
Left justified is a variant of I2S with a 1 bit timing shift of the data. It is easier for some chips to handle. Audio ADCs and DACs are all at least stereo because why wouldn't they be...
Best done with DMA, although more complex to setup - interrupts are subject to timing variation from other interrupts, critical sections etc.
The Audio library analog input class might be a source of inspiration.
4 channels? They would run in parallel, so BCLK for 32bit 768k is 64 x 768k = 49.152MHz, which has a period of ~20ns. There might be a ratio between MCLK and BCLK, but its not to do with channels, hopefully the device doesn't need MCLK anyway?