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  1. E

    Teensy 4.1 Ethernet Trouble Shooting

    This is the code. It's basically just the setup code from the raw frame monitor. I confess once I'd got my ping that was enough to validate the hardware, so I've already passed the hardware on. #include <QNEthernet.h> using namespace qindesign::network; // Main program setup. void setup() {...
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    Teensy 4.1 Ethernet Trouble Shooting

    Thanks all. I swapped to QNEthernet. The link was up immediately but the IP took a few minutes to get assigned.
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    Teensy 4.1 Ethernet Trouble Shooting

    Hi All, I'm having trouble getting a successful ping from my teensy 4.1 project using Ethernet. All I really need at this stage is to get a ping through to confirm the hardware is working. For code, I've used the example chat server, just changing #20 to #include <NativeEthernet.h> For the...
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    MIDI device emulation

    You're effectively wanting to make an emulator for one of those controllers, to which end you'd need to copy exactly how the controller behaves, which you'd probably need to get a hold of one of the controllers for.
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    5V Teesny 4.1

    If you're supplying Vin as 3v3, then there's nothing to worry about, as the modules won't have a way of stepping the voltage up. You might want to check if 3v3 is within the safe operating range of the parts, as even though it runs now, you might be shortening the lifespan.
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    Teensy 4.1 VIN, VUSB, USB host +5V?

    Yes, it's actually a reasonably elegant way of doing things. You've got VDD_SNVS_IN which needs to be the first 3v3 (ish, it accepts something like 2-3.5 IIRC) line powered, but the hardware needs to also accept the use of VBAT, which is your battery connection for a real-time clock. So the...
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    Teensy 4.1 VIN, VUSB, USB host +5V?

    My first glance wasn't quite right. USB_VBUS will power VDD_USB_CAP which through D1 will power VDD_SNVS_IN, which is the bank PMIC_ON_REQ is on, which is pulled up. So eventually the 5V line will enable the 3V3 line, it looks like power sequencing to me. SNVS must be on before any of the other...
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    Teensy 4.1 VIN, VUSB, USB host +5V?

    It looks like some kind of input telling the processor that 3v3 is being supplied. I don't quite know offhand, but I imagine it's some kind of feature that prevents the teensy from trying to boot if 3v3 isn't active. You'll note a hardware pullup to 3v3 is also included, thought weak at 100k. It...
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    Input jittery

    Yeah, that's an idea, it's called fast edge slugging/spectrum limiting and it's basically used to remove the highest frequency components from a square wave to reduce the emissions. You can definitely do it in hardware, and It would be cool to know if the T can do it in software. I'd note that...
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    Teensy 4.1 VIN, VUSB, USB host +5V?

    pjrc.com has schematics for all boards that might make some things like this easier to understand. Suppling 3V3 directly to the teensy doesn't sound like a great idea to me. You'll have to look at the schematic and decide for yourself a) that nothing really needs 5V internally and b) that the...
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    Input jittery

    Nice, sounds like you have a solution. The values of the resistors might have been important, high resistances are more susceptible to coupling in noise. I imagine given your description that it probably is. Some other things you can do if you decide you want to go further - You can change the...
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    Input jittery

    You need to do some sort of debugging to get some idea as to where the noise is coming from. Move things away from your setup, does the noise lessen? Do you still see the noise with your device powered off? Does the ADC have noisy readings even with the thermistor and its wires disconnected...
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    Stacking Teensys

    I'm working on a design for a client, and we weren't sure if a teensy 4.1 would be able to run fast enough to handle everything we need. We have a bunch of time-sensitive outputs, as well as some inputs that need to be run through a control loop. In the end, I've said to the client, and I...
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    Teensy Prop Shield Increasing IMU Data Rate

    filter.begin(100); tells the filter function that you're update is 100Hz, so maybe you need to change this. https://www.circuitbasics.com/basics-of-the-i2c-communication-protocol/ is a sensible intro to i2c. inside the NXPMotionSense.cpp Wire.setClock(400000); sets the I2C clock to 400k...
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    Teensy Prop Shield Increasing IMU Data Rate

    Hi Lopenguin, Welcome to the forum. If you could post your top-level code int wrappedInTagsLikeThis; that would help. Look for the hash symbol at the top to get the tags. I presume you're using one of the examples in that library, but it would be easier if you posted so people don't have to...
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    longevity and sealant

    This question is pretty vague, and it's impossible to estimate the lifetime of your project from your description. Conformal coating is used to add an extra layer to assembled circuit boards, to protect them from the atmosphere and hence increase longevity and also decrease the likelihood of...
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    T4.1 Invert I2C pin-out?

    The I2C, as Mark says, is set in silicone. The chips have dedicated hardware to run these busses that are only available on certain pins. If you mean to say you want to swap the pin locations you can't do this using the teensy's hardware. I'm not sure I understand why you can't use the...
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    Arduino coding question --

    The answer to your main question : The code that prints the key stroke is executed in bubbleSort(), line 119 counts is set to the value of median and the key is determined from that. bubbleSort() is called at line 70, but the value of median is determined at line 73. Hence bubbleSort is sorting...
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    Simple PWM inversion used to drive an H-bridge used for motor inverter

    I've not heard of using synchronous rectification with a H-bridge, but if I've understood, that would require opening the appropriate MOSFETs in Phase with the supply. Surely that would require two PWM signals 180 degrees out of phase with each other, not a balanced pair?
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    What is a/the use case for analogWriteResolution with resolution < 16?

    It's just a function of how the timers work out. A simple view of a PWM is a counter that counts up to number, turns on at zero, turns off at X, and resets at Y back to zero. Let say your counter can increase at a rate of 1 a millisecond. You could have a max count of 3, giving you two bits...
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    Simple PWM inversion used to drive an H-bridge used for motor inverter

    Hi smuscat, I'm not sure I understand your project. A H-bridge can drive a motor in either direction, by turning on two out of four motors. For each pin of the DC motor, one MOSFET can connect this to high and one to low, and the same for the other motor pin. In this way one side of the motor...
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    SMD I/O and SD Card I/O

    I'd recommend Pogos, I think they'd be a lot less faff than trying to get a connector to fit. The issue I've had with connectors is getting them to line up on the SMD pads so they mate properly. There's a lot of pins on the T4.1 to line up as it is. OshPark's flexible PCBs are pretty good. If...
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    SMD I/O and SD Card I/O

    it depends on how neat a solution you're looking for. If you're making a PCB to receive the teensy, you could place pogo pins to contact the pads. Or you might have to look around and find a connector that fits if you trim the legs to size. Male pins might be easier for this. You could get a...
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    Inductive Sensors MIDI Keyboard

    Yeah you can drop in the USB port you like, and then just connect it up directly to the teensy. The micro USB on the teensys is a little delicate IMO, so actually using a beefier option is a good shout. You're not wrong actually, perhaps the right move is to get a full PCB made up, but only...
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    Keyboard matrix behaves differently based on choice of row pins

    it looks like you've derived your code from the example file multikey, which is fine, but I don't understand the use of lines 35-41 where you define the columns as outputs and the rows as input pullups. I would think that this is probably being undone by the internal code to keypad.h which would...
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    Inductive Sensors MIDI Keyboard

    - The teensy lc is designed to be plugged straight into the usb, so J1 and U2 are a bit redundant. You should also crunch the numbers on how much 3v3 current you need, as while the regulator will supply up to 800mA, the USB you plug into might not. - "Long" is incredibly varible in terms of...
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    MDD (MDIO/MDC) library for Teensy

    Further to this, I've not found any such library and I'm definitely going to need something to do the job as I actually need to drop in a micro to change a single register at power on. The MDIO interface is pretty similar to I2C, with a data line and a clock line, with one master controlling the...
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    RPLiDAR with Teensy 4.0

    If it makes an audible sound when crashing, my first thought is brownout. Looking at the lidar datasheet, I can see the maximum current draw of the system might exceed 500mA, which for some USBs would be too much. If you're powering this from a laptop or a USB port of unknown current output, try...
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    Keyboard matrix behaves differently based on choice of row pins

    You've not really given enough information, if you post your code and a schematic someone might be able to help. I'm also not entirely sure of the error you're seeing, are you finding that the key presses trigger a different output than the one you expect?
  30. E

    Oled display only functions when connected to arduino ide

    My first question, is have you got your power connections in order? The program not working without the USB connection would suggest to me that there's a problem with that, I'm going to leave the whole IDE open thing for now, let's make sure the power is good first. If you put...
  31. E

    Source for PWM EXT_CLK on Teensy 4.0

    Well, you could implement the change in frequency by changing the time base in the Timer3.Initalize(), though the resolution towards 1kHz would start to drop a bit. Changing phase again doable, but I can see now why you're preferring the external CLK option!
  32. E

    Source for PWM EXT_CLK on Teensy 4.0

    Perhaps a better phrasing would have been: "what can be considered significant jitter on 1Hz PWM signal?" It's about the same. Though when I put a bit of random code into the void loop (some additions, delay, and a serial println deliberately to have something else using an interrupt), it...
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    Source for PWM EXT_CLK on Teensy 4.0

    Ok well that's grand. I do have to ask, academically, what constitutes jitter on a 1Hz PWM signal? Looking at the above on the scope, I'm getting a jitter of about 500ns, for the off cycle. I'm also observing an average off time about 500ns under 250ms. Ie 0.2m% on both counts.
  34. E

    MDD (MDIO/MDC) library for Teensy

    Hi All, I'm designing an ethernet repeater, and I was looking at ways to debug it. I'm not planning on having anything manage the link, it's just going to be two phy's back to back with the RMII interface. It does occur to me, that having some way to access the MDIO/MDC bus externally would be...
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    Source for PWM EXT_CLK on Teensy 4.0

    You'll need to find the pin from the datasheet, then look at the T4.0 schematic and see where it's connected to the teensy's header (assuming it is, and I wouldn't guarantee it), and then you'll need to figure out how to tell the processor to use that clock. That being said, you might find it...
  36. E

    Teensy 4.0 digital interrupt threshold

    Logic levels are a product of the hardware and can't be changed, additionally, when you find the appropriate datasheet you'll be given a voltage below which a 0 is guaranteed and a voltage above which a 1 is guaranteed. Between the two is known as the uncertainty region as it's - you guessed it...
  37. E

    TCP Communication: Teensy 4.1 and Raspberry Pi

    Assuming you're using arduino ide File->Examples->Ethernet has a bunch of examples. Obviously, you're not interested in the UDP examples, the ones with UDP at the start of the name.
  38. E

    A teensy controlled adjustable load

    Here's a picture of V1! I've been working on a ~1kW adjustable load for work, because I'm doing a lot of PSU design, and it's getting awkward testing them. You can buy a big high power resistor, but they're ~£100 a time and absolutely terrifying. Having a 40cm resistor on the desk sitting at...
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    Teensy 4.1 driving opto relay directly?

    BriCom'sp suggestion of a buffer chip would work just fine, or the simplest thing would be to use a MOSFET. Assuming you're using this for some kind of slow switching rather than signalling. Referring to the pins as noted in the datasheet, connect pin 1 to 3v3, then a resistor in series with a...
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    Instrument w. Polyphonic Sample Playback

    Yes, your project seems possible :) Presumably, you mean to store the samples on the card, and then unload them into memory at runtime. I guess it would be a case of comparing read speeds from the memory card, vs the data rate you'd need in order to get these 6 samples out - 6x 14 bit, 44kHz, =...
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    HID Gyroscope Device/Gamepad

    Ahh, I see. I didn't realise you were working with some software, so my comments about sending the data don't apply sadly. If you want it to work with that reWASD, you'll need to find out what format it wants its data in and push that out over USB. I imagine there is a standard for gyroscopic...
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    T4.0 ISR Rising Edge Voltage Trigger Level?

    Oh wow, the answer's right there! I confess I've yet to use a T4, which is why I've never seen this before. If you crack open pins_teensy.c in the T3 core files and compare it to pins_digital.c (as frank has shown above) the difference shows itself. Yes my changing a single bit statement is an...
  43. E

    T4.0 ISR Rising Edge Voltage Trigger Level?

    Well clearly the pullup resistor is changing something, what are the resistor values you're using for the divider compared to the internal pullup? Have you looked at the signal with and without this pull-up? is inaccurate. What you mean to say is "the ISR was producing an output in a manner...
  44. E

    HID Gyroscope Device/Gamepad

    I've used maybe 15 adafruit libraries, and I've never had a problem with them getting started. Occasionally I've had to re-write my own to replace them where I've not been happy with the performance, but more often than not they work out the box as I need. Speed can be a concern, but the...
  45. E

    T4.0 ISR Rising Edge Voltage Trigger Level?

    Good that you've figured out a fix. I wouldn't point the finger at the documentation when really this is a fix for your specific setup. Input_pullup adds, as you probably know, a pullup resistor to the input to 3v3, and has changed the processing of your signal. What this suggests to me is that...
  46. E

    5V Teesny 4.1

    I think it's worth pointing out that the teensy 3.5 and 3.2 are 5V tolerant, that means while they output 0-3V3, they won't be damaged by a 5V input on their digital pins. Think of it as an input-only level shifter if that helps. Say after you look through your modules, some are happy with 3v3...
  47. E

    Amplitude analysis of .wav file and cue points

    I think, particularly as a second-ever project, it might be a bit much, but don't think for one second you shouldn't give it a go if you fancy it! The teensy-trellis combo is a big winner in my book. You could always get started making a simple midi controller, and then tackle some other bits...
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    Amplitude analysis of .wav file and cue points

    Well, I've been silly enough to be looking at .mp3 files (Serato uses .mp3 for its libraries) which is why the info about .wav doesn't match! are you going to use the teensy for playback as well, or software from a PC? Doing it on the teensy is probably possible, but that's a big bit of code...
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    Amplitude analysis of .wav file and cue points

    I'd probably suggest teensy might not be the best platform for this. Assuming you're using DJ software such as Serato, you'd need to load the .wavs onto an SD, plug that in, get it to do your analysis, and then re-write the file, get it back onto the card, back to the computer, and into your...
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    Filter and Pull-Up Location

    It probably doesn't matter, and my main answer would be "whatever is going to be easier", but seeing as I do love a circuit design discussion - A) An advantage of using pull-ups (active low) signals, is that you can distinguish between no input and a disconnect more easily. If your resistors...
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