Why not use an external pre-scaler IC? I remember that in the 1980ies, most DIY frequency counter stuff was limited by the speed of available logic ICs and reached normally 10MHz. Using a /64 prescaler IC in ECL logic,...
Many software developers are already familiar with Eclipse (which is freeware under Win, macOS and Linux). Dutch developer Jantje created and maintains actively « Sloeber » which is either a Teensyduino compatible...
These are unfortunately things which happen nowadays. Some thirty years ago, the same problems were caused by oxidized IC sockets. The question is if a $29 Teensy 3.6 is worth the effort, or if it's not cheaper and...
Yes, this is always only and unique way to write firmware into whatever Teensy.
The info is somewhere buried here in this 90 page thread. From memory not sure if all 3 SAIs will be fully brought out. Knowing that...
Sorry, didn‘t see that. Can hardly imagine a use case with the need of 14 Midi ports especially since midi allows theoretically daisy-chaining devices, concentrating or adding up several streams on one port.
I’m now...
Unfortunately, you do not tell us everything about your project, so it is difficult to give a pertinent advice.
The first question is, why is OTA needed in your project? As an old school developer, I aim towards...
Can’t understand your over-complicated approach. The Teensy 3.6 has 6 hardware UARTs. Each of these might serve for a 5pin Midi port. No need to waste cpu cycles and ram for bit banging with a soft serial emulation.
You should study the processor reference manual (free pdf on the PJRC website). All Teensys have extremely flexible and powerful hardware inside, like for your needs the FTM and the PIT timers, which can never be fully...
That is a contradiction with the current principle of operation inside the Teensy and Teensyduino ecosystem. People buy a Teensy instead of a bare K66 CPU to get all that Teensyduino stuff, library support, and Arduino...
Different speeds means different I2C busses. Changing the I2C data rate "on the fly" might result in timing problems.
If I were you, and if it's really needed to go with such high speeds, I'd put the faster devices on...
The global pointer variable must be declared volatile, since it will be modified within an ISR. After that, at least the pointer should be incremented at each run of the ISR.
That seems not to be the way the Teensy 3.6 is intended to work. All Teensys come with an external bootloader chip on board which handles the upload process through USB so that no program space is wasted for bootloader...
Several people have already realized Teensy based custom PCBs with MKL02/04 ICs from PJRC. If your contract manufacturer does not want to buy these in the US, buy these yourself and carry or ship them over to the PCB...
There are s viral distributors in Europe which sell the well known complete Teensy boards, but as far as I know, the MKL02/04 with preloaded bootloader can only be bought directly from PJRC
The clock speed is set during compile time, using the corresponding clock speed option in the tools menu of the Arduino IDE. There you select a clock speed between 4MHz and 96MHz. Editing the corresponding boards.txt...
I didn’t intend to insult you. If it came out this way, please accept my apologies! I know that my non-native English is not up to refined diplomacy, but I do my best to improve.
The first part of my previous post...
Several people have already gone that path. It seems that fully reading a documentation and data sheets has become unmodern... odds are good that the line out will still work if the SGTL has not heated up too much due...
What you consider being an error is the laws of physics (7th grade stuff). As I explained already, the freqmeasuremulti library measures not frequencies but period durations. The period time is defined as t = 1/f. If f...
Pin compatibility exists basically and especially for these functions which are traditionally bound to specific pins since the earliest Arduino days. That means that you’ll almost always find at least the same functions...
I still don’t see a precise timeout handling for your period/frequency measurements.
And you have enormous delay() times in the loop. Imagine one of the frequencies being around 100Hz. During a 300ms delay, it would...
Sorry, can’t understand what you mean by that?!?
Removing a signal from a pin means that the frequency will be zero. Thus, the period time which you get with read() will be theoretically infinite. So, you would have to...
Too slow? Too slow for what? Please post code which demonstrates the problem.
I think you have read the read me file of the library which states that precise measurement is only possible for frequencies < ~5kHz and...
Just to satisfy my scientific curiosity:
The -1ppm which you measure in the original post will lead to an error of less then 1 second over 10 days. What kind of application would consider this as not being sufficiently...
Then, you'd check if this noise gets through to the ADC results. It might be that the sampled results are ok, though, since the the integration period of these SAR-delta-sigma converters is probably longer than these...
Yes.
BTW, I'm don't think that analogWrite(x,255) in Arduino does a true "always on". That's why Teensyduino improved that function. Thus, by writing 255, you should get the same, an "almost always on", on both,...
Conclusion: Teensyduino is smarter than Arduino.
Look at the source code of analogWrite() in the Teensyduino core files and you will see that analogWrite(255) will and can never be "always on" since the timer modulo...
It is (within several limits, for example no USB audio). Several discussions about this topic exist already in these forums. Please do a search.
A starting point could be utility/pdb.h where you might modify...
The standard safety requirement in Europe is 1.0mm^2 copper wire section per 10A (which corresponds to AWG17), independent of the voltage. For full 60A, you'd need 6 of these wires in parallel or one AWG9 wire.
This...
The "problem" might be that you have added capacitors to Vcc and to the buffered Vcc/2 after the first op-amp. Both sources are Lo-Z, so that there is no true RC low-pass filter effect. I'd modify the circuit as follows:
Why not simply shifting the incoming bytes into an unsigned 32bit integer and then compare for the command sequence pattern?
uint32_t sr;
sr = (sr << 8) | newbyte; // each time a byte arrives
after 4 Bytes...
Even if you ask friendly, nobody will most probably sit down and write code for you for free. These forums are intended to point people towards the needed resources, so that they get the tools at hand to write their own...
The problem is that (AFAIK) we Senior+ can only block users via deleting a spam Post in the forums. Users which only send PMs but never posted in the forums seem unfortunately out of our reach.
@rotabox: Why don’t you systematically study the source code of that library until you really understand every single line? Afterwards, it will most probably be very easy to do the needed modifications. The other...
So, random returns an unsigned value. Which explains the overflow after the subtraction when the result is expected to be negative. Which goes conform with my interpretion of the high values above.
The program pins have relatively weak pull-up resistors internal to the MKL04. After making sure that the MKL04 gets 3.3V at its pins 3 and 4, you might look for something which pulls the pin down. For example, if your...
The huge numbers ARE cast errors, they are the binary 2-complements in a 32bit structure. Subtracting 2^32 (4 294 967 296) from these gives the expected -2, -5, -3, -1, and -2.
On Cortex M4F processors (Teensy 3.5...
Why would you waste RAM and CPU cycles for a float with double precision (double x), when a simple int8_t is more than sufficient? All these type conversions which you do waste time and memory for nothing. And you get...
These MKL04 processors, where did you buy these? You should know that Teensy works only if you buy them pre-programmed from PJRC. Unprogrammed MKL04 MCUs will not work.
An unprogrammed "virgin" Teensy always shows up as a HID device. That's normal and ok - the Teensy loader will be able to flash it over HID. If you want it to show up as a Serial device, you'll have to load a hex file...
In opposite to the Teensy 3.2 which has internal PGAs which might optionally amplify an input signal up to 64 times, the Teensy 3.6 doesn‘t have these, thus you have to find other ways to optimize the ADC resolution,...
There's a paper on the internet which explains the theory behind: Sampling Rate Impact on the Tuning of PID Controller Parametersijet.pl/index.php/ijet/article/download/10.1515-eletel.../244
You haven't forcibly to rely only on the FTM timers for generating 4 different frequencies. Many roads lead towards Rome. But to make meaningful suggestions, a little more info would be needed:
Are these 4...
These converters are for simple digitalsignals which occur in the analog synth world as gate or trigger signals which are either low(0V) or high(5V).
CVs are much more complex, since (let’s take a pitch CV example)...
The golden “Moog” standard for control voltages (CVs) in the analogue synth world since the early 1980s is as follows:
Volume: 0V (mute) to 5V (full volume)
Pitch: 1V/octave centered around “middle C” or midi note...
Novice user in the title was interpreted by me as novice with the Teensy. That doesn't have to be a contradiction to owning a brilliant diploma in engineering sciences... :cool:
And still then, there is a risk of multiple events with one button press, due to mechanical contact bounce/chatter. You need a de-bounce algorithm for each button. The Bounce library could be of great help.
No 5V, this will kill the analog inputs.
From your picture, I see one end of the pot connected to +3.3V with a red wire. I see the wiper of the pot connected to teensy pin A0 with a black wire. I see the other end...
If the current delivered is limited to 20mA and the 150Ohm is always connected, the voltage can theoretically never exceed 3V. The Zener will hard limit it to 3.3V if the 150Ohm fails. So, theoretically, 12V (from where...
Your "Arduino analog input model" does not apply. The Teensy's ADCs are delta-sigma SAR converters which have a switched capacitor input and thus a non constant input impedance. This explains the voltage drops. If you...
So, in order to dim the LEDs, a multiplication of all R, G, and B values with the same attenuation factor could be a solution. If using a T3.x, there are DSP instructions which allow packed multiplication of up to four...
It was commented out because each declared WIRE instance eats up a few system resources, if used afterwards or not. And WIRE3 is a fourth I2C bus. Seen that each bus can theoretically handle 120 devices, under condition...
If you "read" these FSRs at low rate, you might, if needed, still apply some low pass filtering in your code. I wouldn't overthink that for the moment and keep it simple.
The ferrite is (IIRC) small, around 0.6uH and...
The ferrite has two functions. First, it shall remove digital noise from GND. Second, it is intended to be the one and single (to prevent ground loops) required DC reference connection point between GND and AGND.
...
Man... Open the applications folder on your Mac, right click on the Arduino app icon, select "show package contents". Then navigate through Contents -> Java. From there, follow the path which defragster indicated.
The I2C bus is sensitive to wiring capacitance and inductance. Thus, things that work on one board layout will not forcibly work on a different board layout. Best practice is to plan pads or holes for the series SMD or...
A quick look onto the Teensy 3.6 schematic will tell you that everything comes from the same LP38691 voltage regulator. So, the maximum current which might be drawn in sum from all 3.3V pins is 250mA.
What does the data sheet of your LED strip say, which logic voltage is required? If it’s 5V, the answer is clear: You need a level shifter of the 74HCT125 or 74HCT245 type. Simpler (and cheaper) level shifters with only...
Yes and yes. You might also look for inspiration at the source code of the analog input objects in the audio library. Here, the PDB is used to trigger timed conversions (44.1kHz) with high precision.
The Teensy is not an Arduino which has a boot loader program in its flash memory.
The Teensy’s flash memory is 100% dedicated user program space. Uploading is handled via a separate processor on your Teensy board, a...
The risk of Vusb driving Vin is there. But as always in life, there are no 100% fool proof solutions. In my designs, this third diode does not exist. So, either everything is powered from Vin, or Vusb is applied, just...
One day, I’d like to understand why people buy and connect 5V peripherals to 3.3V processors... Nobody would replace their 12V car battery with a 24V pack from a truck...
Friends, the 5V era is almost over! Don’t buy...
3 Schottky diodes should do it:
The upper diode from Vusb to Vin is not forcibly needed, it is thought as a helper for those who expect to feed peripherals connected to Vin from the USB supply
Seeing 3.6V means the Teensy’s pin protection diode is trying to limit the voltage by clamping it to 3.3V, having itself a forward voltage of 0.3V. You are definitively in the danger zone, here!
Then, look at the FreqMeasureMulti library. It can work on up to eight pins (5,6,9,10,20,21,22,23) if I remember well.
BTW: The FreqCount library works like a “classic” frequency counter, which means that you need a...
Without having looked it up, I’d guess that in the meantime, a few TFT controllers with QSPI interface should be available, thus making the bottleneck four times wider...
I guess that it it’s time to think about a “Teensy G”, a graphics (sub-)processor which would communicate with whatever “main” Teensy through a simple command set, similar to the gfx libraries and which would then care...
The words "longer wires" are crucial - there it is where the root of all problems lies. The I2C standard had been invented by Philips to allow communication between ICs which would all sit on the same PCB or on...
That's wrong. It's all the time about impedance matching between the source, the transmission line, and the destination. That can work with series resistors under certain conditions.
In fact, if you do not want to...
I guess, the problem comes from another side. Even if you try to install a maximum of protection, the idea of just plugging and pulling the plug seems bad in conjunction with what I guess are switched mode power...
It seems normal to me that, if you add a device to the bus, the bus impedance (be it capacitive, inductive, or resistive) changes and the termination and source impedance have naturally to be adapted. That’s pretty much...
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