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    Teensy 4.1 How to start using DMA?

    That is definitely interesting, I didn't imagine shifting data out at those speeds was even possible :oops: I have zero knowledge of the FlexIO module so I'll look into that. I'm trying to create a system that creates at least 256 WS2811 channels. The library seems to be limited to one data pin...
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    Teensy 4.1 How to start using DMA?

    Thanks, that helps a lot! (I was assuming the GPIO DR_SET registers were located right next to each other for some reason 🙄) I'm trying to adapt the library in such a way that it controls WS2812 LEDs through shift registers to allow even more channels to be addressed in parallel. Similar to...
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    Teensy 4.1 How to start using DMA?

    Hi, I'm trying to understand how the DMA's are used on the Teensy 4 in the OctoWS2811 library. By looking at the following lines I can decipher that dma1 is used to set the pins high at the start of the WS2811 waveform, dma2 to set it high or low depending on the data in the bitdata buffer and...
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    SPI weirdness: transfer() returns before finished

    Thanks for your reaction. I added delayMicroseconds(1) before digitalWrite(CSPin, HIGH) to no avail. This doesn't seem to be a problem with the CS though, I tried leaving the CS pin HIGH during the transfers by removing the digitalWrites to CSPin, and see the same behavior on the scope where the...
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    SPI weirdness: transfer() returns before finished

    Hi! I was wondering if anybody could help me make sense of the following. I made a PCB that hosts a Teensy 4.1 and various IC's that communicate over I2C and SPI including six MAX31865 RTD-to-Digital Converters. I'm trying to get the Teensy to communicate with one (any) of the MAX31865's over...
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    Teensy 3.5 Hardware Serial pause sending (Software controlled CTS)

    Thanks, I got it to work in two ways. I think the way you meant is by using the "Transmitter Interrupt or DMA Transfer Enable" (TIE) on "UART Control Register 2" (UARTx_C2). Which I set by calling "UART0_C2 = C2_TX_INACTIVE" when wanting to pause and "UART0_C2 = C2_TX_ACTIVE" when wanting to...
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    Teensy 3.5 Hardware Serial pause sending (Software controlled CTS)

    Hi, I'm dealing with a situation where it would be great to be able to control the "Clear to Send" (CTS) signal of Serial1 using software. I see I can enable CTS flow control using Serial1.attachCts(pin) where pin can be 18 or 20, but what I'm looking for is something like Serial1.pause() and...
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    Teensy 4.0 with OctoWS2811

    Yes, please go ahead :)
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    Teensy 4.0 with OctoWS2811

    Thanks! I was waiting for this! Directly upgraded two of the LED walls you can see in the video which were using OctoWS2811 on a T3.6 to a T4.0 and the increase in performance makes the animation run way smoother! It went from varying around 40 fps to maxing out at 140 fps (the limit for the...
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    Guidance for creating a 128x128 ws2811 LED display

    I don't fully understand why only a maximum of 3 boards may be used with one sync pin. I would not be surprised if it still works with four boards anyway but if you want to be sure you can just assign a second pin to send out the sync signal as well and then split the boards up over those two...
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    Guidance for creating a 128x128 ws2811 LED display

    Yes indeed, since the USB port has a bandwidth of 12 Mbit/s and you have (128*128*24) 0,393216 Mbits in every frame, the maximum theoretical framerate would be (12/0.393) 30,5 fps. When rendering the images directly on the teensy you of course wouldn't be limited to that framerate. You could...
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    Guidance for creating a 128x128 ws2811 LED display

    Splitting it up would be a valid solution, the question in that case would indeed be how to connect them together. I imagine things can get pretty complicated if you're going to render the graphics directly on the Teensy's regarding synchronization and alignment of the graphics between the four...
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    MultiWS2811 - Simultaneously Control 128 WS2811/Neopixel LED strips

    The schematic can now be found here. I'll soon make some pictures with the oscilloscope and explain it in more detail.
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    MultiWS2811 - Simultaneously Control 128 WS2811/Neopixel LED strips

    After having done multiple projects using an increasing number of WS2811-based LEDs, I hit a point where more channels were needed than OctoWS2811 could provide. That's why I created a library and an adaptor board for the Teensy 3.6 that allows 128 channels of WS2811-based LEDs to be controlled...
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    "Absolute" positioning

    Have you looked into the HTC Vive tracker? You can get the trackers seperately but idk whether you can buy the base stations without the VR headset though...
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    Connecting one Teensy 3.x digital output to many IC's input

    Hi, For a circuit I'm designing I need to connect one digital output of a Teensy to the inputs of multiple 74HCT257 multiplexer IC's. To be more precise, I have 32 74HCT257's and the signal from one output needs to connect to four input pins on each IC for a total of 128 connections. The signal...
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    need help with large screen

    After a bit of digging around I found that the reason for the limit is probably explained by the 15 bit limit of the Current Major Iteration Count (CITER) (24.3.28 p.561 of the k66 manual). I guess this means that the minor loop technique used by https://github.com/raplin/HexaWS2811 actually...
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    need help with large screen

    I'm working on a library based on OctoWS2811 on the Teensy 3.6, and I'm trying to figure out what exactly is causing this 32K bit limit and if there would be a way to circumvent it. Would it for example be possible to chain two transfers after another? or start two DMA transfers simultaneously...
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    Maximum sizie of WS2811 displayMemory

    I'm using the K66 Teensy 3.6 now but it still doesn't work when configuring more than 1365 LEDs per strip. Does the library need to be adjusted to support the larger memory of the Teensy 3.6?
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    Simultaneously start multiple timers

    Thanks! I'll look into both options and report back ;)
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    Simultaneously start multiple timers

    For a project which requires precise timings, I'm trying to align three PWM signals from three different timers; one 12 MHz, one 1.5 MHz and one 0.75 MHz signal. As far as I understand this would require all three timers to start counting at the same time from 0. The only problem is that I can't...
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    Periodically interrupting PWM signal using DMA

    Hi, I've been trying to create a high frequency PWM signal which is periodically interrupted by a lower frequency PWM signal. By studying the OctoWS2811 library and the MK20DX256 Manual I've created the code below. I'm using two timers; FTM1, which creates the to be modulated signal and FTM2...
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    Teensy Audio: AudioOutputUSB only working when combined with different AudioOutput

    Hi! I've ran into a bug in the Teensy audio library when playing audio over USB. Apparently "AudioOutputUSB" only works when there is also a different audio output (like AudioOutputAnalog) present in the sketch. The following code should send a sound over USB but it only works when...
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    Teensy 3.1 crashing, memory problem?

    Yes that fixed it, thank you so much! I feel a bit stupid right now... :rolleyes: In an earlier version seg indeed was an array of Segment objects, but after I changed it I apparently forgot to change segAm accordingly. by some lucky chance (or unlucky actually) everything was still kept in...
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    Teensy 3.1 crashing, memory problem?

    I'm quite sure this is not happening here. The code runs fine, even for extended periods of time. But if I add one extra variable to the class, just for increasing the size of the class so without actually using it anywhere else, the program freezes during runtime. It can't be a memory size...
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    Teensy 3.1 crashing, memory problem?

    Hi, I'm working on the code of an installation that uses a teensy 3.1 with OctoWS2811 to control leds. Here is a bit of an old video of the installation to get an idea: https://www.youtube.com/watch?v=0KjQS3GsGWQ This "Creative Mind" artistically represents a neural network with the spheres...
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