Stencils are designed to be stretched taut in a stencil frame, the fact the stainless came off a roll (which is why they
have a curve) wouldn't normally cause issues used with a frame (might make storage an issue...
Perhaps a link to the datasheet for the parts in question? - better than trying to guess what "high definition"
might mean to you, 1000 PPR, 10000 PPR, or even more?
How many encoders are likely to be changing...
Python3 bytestrings are not the same as unicode strings (Python3 strings are unicode). A bytestring is notated b'xxxxxxxx'
Python3 strings can be interconverted <-> bytestrings if you give the encoding to use.
This...
ILI9341 is a chip, not the actual TFT display. This sort of thing is why you should try to find something with a decent datasheet.
I'm sure there's a lot of difference between different displays.
One thing you...
No, those signals are way too small to be fed direct to the ADC and get anything meaningful out.
An instrumentation amp is probably the way to go, though you'd need to ensure the potentials fall within its input...
Forum rule? This is a software problem I think, the dropout is one audio block I suspect, ie 2.9ms, although
your 'scope shots omit timebase info so that's a guess.
The pin probably has bus-hold enabled.
See this thread:
https://forum.pjrc.com/threads/69671-Teensy-4-0-4-1-web-pages-need-a-warning-about-INPUT_DISABLE-on-Analog-Inputs?highlight=bus-keeper
When begin_v2_b2() returns all the audio objects have their destructors called and cease to exist. This won't be useful, and won't
work at all because audio objects that do I/O set up DMA and interrupts which are not...
That's the point - the signal "bypasses" the diodes unless the input voltage strays out of range, in which case one of the diodes
conducts and clamps the voltage.
Two Schottky diodes and a Teensy (or any CMOS logic chip at all). This is the standard voltage protection - for surface mount people
generally use a dual Schottky in a SOT23 package for this.
You could get away...
To get precision timing the #SYNC line probably should be driven in hardware from, say, a PWM output set to the right speed.
Then the code to read the data can be interrupt driven from #DRDY going low.
Issuing...
Zeners are not really the answer (they can have pretty soft knees in their response too), the way to do this is with a pair
of Schottky diodes to the rails and a series resistor:
The value of resistor needs to...
I believe the range depends on which FFT window is used as they are not normalized for level IIRC.
Perhaps connect a AudioSynthWaveformSine into AudioAnalyzeFFT1024 to find out? A full-scale sinewave will
produce...
20MHz is just about doable on a breadboard, but you must use good layout - short direct cut-to-length wires, form a ground-plane
(well, ground-grid) using regularly spaced ground links. Decoupling capacitors for all...
Maybe use star-grounding for the various power supplies? I see several loops in the ground including high-current paths, which isn't a
great plan. Try to ensure any signal wire only runs alongside low-current ground...
The audio shield socket does not have microphone connection, and is definitely intended for a TRS cable. If you need a microphone connection
you'll need a splitter.
Thinking about the SGTL5000 headphone output some...
A 'scope allows you to check the signal integrity on the bus - needs to be reasonable bandwidth for high speed logic, 100MHz+ really.
This is the sort of problem a logic analyzer will not help with (in fact it may...
The band limited waveforms are a succession of step functions, at arbitrary timing, so its a little different from a succession of
samples so I fear the code won't translate well. There are several pertinent threads...
Are you sure the T4.1 pins have enough fan-out for that may loads at high speed? This sounds like a case for a high-current logic buffer, or a distribution-tree (T4 drives 4 buffers, each drives 5 loads?)
You probably have some CTIA<->OMTP adapter cables then, which are have different pinouts at the two ends.
I'd stick to TRS (3-pole) 3.5 lead for standard audio (as opposed to computer/phone headset use). There are...
Playing a sampled waveform back at various different rates is a problem of interpolation or decimation, ie rate-conversion.
Straight IIR and FIR filters only work when the input sample rate is the same as the output...
The address is local to the bus, its set in the hardware of the device. If you have a device that doesn't allow selection of alternate I2C addresses you have to use multiple busses or an I2C multiplexer.
It seems that example only scans using the Wire object (SCL0/SDA0), not Wire1 (SCL1/SDA1).
Seen: https://github.com/nox771/i2c_t3 - its mentioned on the Wire library page.
You know the Teensy runtime already sets up the clocking before setup() is called? You may be misconfiguring things
if using a code example that's designed to run from reset state?
Vehicle supplies are very noisy and spikey - normally you'd have filtering / clamping circuitry to tame this.
https://www.avrfreaks.net/forum/automotive-power-suppy-filtering
I2C is indeed limited range - its...
Two gains and multiplying are necessary in fact :)
You were looking for a cross-fade in particular, but didn't use that term, which I think helped sow confusion
especially as we've been talking about exactly that...
So no 3-phase induction motor? That's the ultimate challenge - easier with an encoder.
Yes, a 4-quadrant motor controller needs a rail clamp circuit (braking circuit), that's pretty much essential for motor control...
Now I've even more confused - you said you didn't want multiplying or gain, and how you want a wet/dry control which necessarily
has gains and therefore multiplying.
Do you want :
constrain ((g1 * (a-511) + g2 *...
I don't get your point - you have 10 bit unsigned ADC data by the sound of it, but not using the Audio library (is there a deep reason for this BTW?), so clearly you have some other framework in mind - but what? Is the...
Interesting - not come across the DRV8301 before, seems quite complex but I can see the benefit of some of the protection features.
What motors have you managed to drive?
That page dates from the days when all Teensy's were Atmel based, ie Teensy 1 and 2. Its specific to that hardware, so not relevant to T3's or T4's (which didn't exist when the page was written I believe).
The...
I know I'm resurrecting an old thread, but I just measured the MCLK spectrum on a T4.0 so can show what it actually looks like:
This was with TDM at 48kSPS, BTW.
It strikes me that for best quality a separate...
There are a lot of examples of reballing BGA chips on YT, but this tutorial seems to be a good one for the initial
soldering of a BGA package on a new PCB:
https://www.youtube.com/watch?v=15RFI9wKHq8
Disclaimer:...
Have you tested with the 10k/1nF yet - that ought to keep the slew-rate down to something a sigma-delta ADC can actually handle without aliasing issues. The TL072 is fast from what I remember (20V/µs?). The SGTL5000...
You should double-buffer the output, so you can calculate one batch of 16384 samples while the previous is being output. Then you have 1/3s or so to work with.
In what way? Every operation depends on a previous one, no scope for such optimization or even take advantage of dual-issue.
To calculate MFlops/s use: 20 * 24 / (floptime / 1000.0f)
MFlop count _divided by_ time...
You've not selected the input on the SGTL5000 or set the output level - perhaps add these in case the defaults aren't what you expect.
sgtl5000_1.inputSelect(AUDIO_INPUT_LINEIN);
sgtl5000_1.lineOutLevel(15);
...
You need to protect the audio adapter from over voltage on its inputs, there is no protection on the adapter and
there's a definite risk of frying it if you have +/-9V. I worry you've already done damage.
A series...
Sounds like you need a clock recovery algorithm that learns the frequency and tolerates (upto some limit) delayed or missing MIDIclock messages.
Clock recovery is a big thing in comms, there'll be all sorts of...
Again, decide which coordinates you are using and stick to them - if you are using the stepper steps, you'll have to convert encoder values to stepper steps before using them, or vice versa.
Why are you calling...
Lower the inductance between the crystal ground pin and the plane? You've squeezed it into a thin trace for no reason,
let it widen as soon as possible by repositioning the top crystal trace lower down?
Don't...
I think AudioFilterStateVariable is supposed to be better for very low cutoff frequencies. Filtering at 20Hz in a 44100SPS system represents a severe test of an IIR filter due to the large ratio between them.
Sampling audio has to be precisely timed or you get distortion due to jitter (it will typically be _very_ audible) - if the sampling rate
isn't constant its equivalent to injecting artifacts, even 0.1% timing variation...
LoRa is not designed for sustained high data rates like this - you have to share the air with all the other users. The use case for LoRa is short packets occasionally - you are wanting to drive a road-train down a...
Could be a code issue. Perhaps you forgot to up the AudioMemory enough as the system became more complicated?
Anyway post your code if you want help on this.
I'd be a little worried by the long wires for the I2S...
The audio library is DC coupled, I think you've simply driven the signal all the way to +1 or -1 (saturation) with the feedback loop. Add a DC blocking filter if you don't want this, ie a high-pass in the feedback path.
Just use 74HCT parts for 3.3 -> 5V level conversion. AHCT is a more obscure family to HCT (slightly faster?).
HCT run at 5V, but accept 3.3V logic input signals correctly. Basically HC are "High speed CMOS", HCT...
You can always just write a sketch to ask the compiler directly, something like this:
void setup()
{
Serial.begin (115200) ;
Serial.printf ("sizeof int %i\n", sizeof(int)) ;
Serial.printf ("sizeof long...
Can you post entire complete verbose errors (in code tags preferrably)?
Unless code is placed in code tags it gets corrupted with emoticons and suchlike, and can't be investigated easily - code tags mean its verbatim.
You need to convert every sample in the array, one by one, that's how C/C++ works. In your first attempt you tried to multiply a scalar by an array, which gives a type error.
Second attempt you are casting the...
You're using ApplyGainThenAdd into a freshly allocated block - you mustn't assume the contents, the memory system only allocates
the memory, it doesn't zero it. If you look at AudioMixer4 update() you'll see it uses...
The gate-oxide electric fields involved are measured in MV/cm (megavolts per centimetre), once something goes,
it can cascade all through the chip as gate after gate fuses shorted.
In particular I wouldn't expect...
12V will obliterate most semiconductors on the board in a few microseconds I suspect. Overvoltage damage is usually
fast and devastating to modern VLSI chips (gate oxide thicknesses measured in nanometres).
You are corrent for 1 & 2.
For Q3, gain of zero in a digital system is true zero - only zero samples can result when you multiply by zero digitally.
In analog mixers this is called "offness", and digital mixer...
The standard protection is Schottky diodes to the rails, which will work even if the Teensy is powered down,
the only thing you need to avoid is the Teensy pin straying outside the Vcc/GND range by more than 0.3V.
The...
Ah, interesting - I've seen "axes" used for CNC machines referring to an indepedent movement axis on
the machine. Channel is the generic term for inputs and outputs, but I can see that specific to joysticks
"axis"...
One thing I found useful was to mark the audio shield pins on the Teensy pinout card with a marker pen, since its
not immediately obvious from the existing information, being a combination of I2S, I2C, A1 and SPI pins
Mains hum is _very_ low frequency from a decoupling perspective - at 50Hz a 47µF capacitor has 68 ohms of reactance, a 1mF cap
has 3 ohms which is much more effective, but at some point the series resistance will...
Basically you almost never use x1 on a x10 probe - primarily because the bandwidth is grossly restricted in x1 mode and the probe tip capacitance is large. x1 is only ever of use for very small signals in a low...
Hmm, suspiciously like mains hum frequency, but that might just be the rate some code is hitting the external bus of course - its sounds to be square wave rather than sine.
One thing that's really useful for...
As I said in reply #5 bipolar-input opamps need smaller values of bias resistor than 1M. I recommended 100k as a maximum for use
with bipolar. With 1M you'd need FET-input opamps for sensible behaviour as they only...
Its worth learning some of the important ones - there's probably some good tutorials out there about opamps, I'm pretty sure Dave Jones at EEVBlog
has one.
Opamps trade raw gain for precision/accuracy, so if you...
Do you realize these chips have a limited range of hardware functions that can be attached to each pin? Many Arduinos and
Arduino compatibles use pins 10..13 as the SPI bus so that limits the use LED pin already -...