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    Dynamixel and Half-duplex serial usage on Teensy4.1

    You schematic can be much simpler if you get an auto direction-sensing shifter; i used https://www.ti.com/product/TXS0108E. You don't need to mess with the direction pin at all. Power the chip A side with 3.3V, B side with 5V Hook Teensy pin 8 directly to A1 though a series ~100 ohm R Hook the...
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    Dynamixel and Half-duplex serial usage on Teensy4.1

    In answer to the above. I can report that it does in indeed work, but with two changes: in the Dynamixel2Arduino library in /src/utility/port-handler.cpp -> void SerialPortHandler::begin(unsigned long baud)..., line 53 change //port_.begin(baud_); // from this, to teh below...
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    Dynamixel and Half-duplex serial usage on Teensy4.1

    I would like to use a Dynamixel servo, using their TTL serial protocol, with the Teensy4.1. There are a number of posts covering similar topics from some time ago, but more recently the half duplex capability of the native UART was added to the Teensyduino library, and I don't see here or on...
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    Numeric Instability, FPU context issue?

    Just wanted to update on this. Between cutting the ISR to just recording a timestamp, and then reducing the order of the IIR filter I was able to get really great results and almost no instability. So the Teensy 4.1 is fully capable of acting as a digital lock in amplifier with a output...
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    Numeric Instability, FPU context issue?

    Thanks Paul, JMarsh. I think I identified the issue. I believe occasionally the interrupt execution is being delayed by about (max) 68 clocks cycles more than usual. Basically the delay spikes to this value, then decays away as certain external signals are synchronized/desynchronized. I am...
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    Numeric Instability, FPU context issue?

    I think what I am seeing is a real effect having to do with the phase of the signal and not necessarily any floating point errors.. It would still be useful to know 1) how to set the priority of an interrupt on a pins 24,25 (GPIO6 12 and 13). 2) if there are any quirks in reading the system clock
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    Numeric Instability, FPU context issue?

    I'm been building a digital LockIn Amplifier. I am seeing very regular instability in the output of calls to e.g. arm_biquad_cascade_df2T_f32 This occurs approximately every 1 million calls, or ADC samples collected. The magnitude of the instability has been found to related to the pretense...
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    Teensy4.1: How to use as sub-board and access USB device

    Great thanks for the suggestions Ken. I hadn't thought of the pogo pins. One question about the Vbus connection. Is it truly not needed to route these to the Teensy board at all? I don't know much about the specifics, but I know with the USB-UART bridges I'd used in the past (e.g. CP2012) this...
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    Teensy4.1: How to use as sub-board and access USB device

    I am planning to integrate the Teensy4.1 onto a larger PCB. (a Eurocard-like 'motherboard') I would like to be able to communicate and program it via the virtual com port as usual but do not want to use the built-in micro-USB. What are my options? Thanks for any help/thoughts. Thoughts: In...
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