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      DrM replied to the thread Future Teensy features & pinout.
      I dunno, peripheral connectivity can be useful, it might have a cost in power and heat. So, as always, you have to think about what it is for, and what other platform might be appropriate, And, as a corollary, the broader the range of use...
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      DrM replied to the thread Software reboot for the T4.
      @PaulStoffregen @jmarsh Thank you
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      Is there a way to reboot the T4 from within a sketch? For example, here is a restart() function for the T3. How would we code a restart() for the T4? #define RESTART_ADDR 0xE000ED0C #define WRITE_RESTART(val) ((*(volatile uint32_t...
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      DrM replied to the thread ADC tests for TCD1304DG.
      One thing I should correct, or be more clear about: With the master clock at 2MHz, you read the device at 500KS/s, or about 8 msecs per frame. For the T4 with its 480 Mb/s USB, the readout from the sensor should be what sets your maximum frame...
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      DrM replied to the thread ADC tests for TCD1304DG.
      In preface, using the TCD1304 (or any CCD), and obtaining results that are useable, at least reproducible and proportional to your light input, is not trivial. Here are some of the issues: (A) light corruption vs "keep clean" and...
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      DrM replied to the thread [no Teensy?] +/-5V power from USB.
      @Angelo Again, that is what it does. It is a working design that has been used for years. It was developed in consultation with another very expert instrumentation physicist and the engineers at Analog, and we do understand impedance, one of...
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      DrM replied to the thread [no Teensy?] +/-5V power from USB.
      @Angelo Thinking about it some more, in the areas that are not directly connected to the IC, maybe I could squeeze it a bit. When you look at it carefully though, I don't think it is going to improve anything very much. But, maybe I'll try...
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      DrM replied to the thread [no Teensy?] +/-5V power from USB.
      @Angelo Here are the layouts from the datasheet (and another of the board). You'll notice they look a lot like the board. In fact, originally, I traced one of them. The other has one mod for the septic. And, the design was reviewed by two...
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      DrM replied to the thread [no Teensy?] +/-5V power from USB.
      @strud Looks nice, pretty good current noise, slew, CMRR, PSRR. Is the max diff input +/-1V, enough for your application? Re the designs. I am posting a series of designs and firmware to my github page. Some of these are designs that I...
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      DrM replied to the thread [no Teensy?] +/-5V power from USB.
      I want to mention two more details about the dual supply design shown in the original post. 1) The LT1930 is used in the SEPIC configuration. The board provides +5V and -5V, even when the input is well below USB, to as low as 2.6V. And, the...
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      DrM replied to the thread [no Teensy?] +/-5V power from USB.
      @strud The LM27762 is a little different. In that device, the positive supply is generated from an LDO. For a +4V output (from USB in) you are probably okay (the LDO will drop out for voltages near USB). Even for a 4V design, I think you...
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      DrM replied to the thread SPI, write 24bits?.
      @Paul Oh I see, you were toggling CS. That is amazing actually, 10ns between transfers. Thank you. That does work out well.
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      DrM replied to the thread SPI, write 24bits?.
      @Paul , thank you. That is super encouraging and very useful, I was wondering what happens to the CS line between transfers. I think that means I might be able to use for the SYNC, though I could just as well tie it high. Anyway, that is...
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      DrM replied to the thread SPI, write 24bits?.
      Well... I found this in the Arduino documentation: https://www.arduino.cc/reference/en/language/functions/communication/spi/transfer/ There it describes SPI.transfer( buffer, size ). So that probably answers my question. Presumably size...
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      Hi, I am designing a board based on the DAC82001. It is a 16 bit DAC with SPI. The figures below show the data protocol. It needs a 24 bits for each instruction cycle. The SPI library has transfer() for one byte, and transfer16() for two...
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      The following is a github repository with KiCAD files for a dual +/-5V supply that can be driven from USB power. github repository for dual supply When designing for microcontroller boards, it is tempting to try to do as much as you can with...
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      Ibsen's calculation for the quantum efficiency of the S11639-01 is here The quote is back from the FAB house. If you would like to piggyback on the order, please let me know. Costs get better with more boards. See the github repository if...
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      This is a new project. First articles are out for quote at the FAB house now. If anybody would like one of the boards, please let me know as soon as you can. Schematics and discussion are posted to github at the following link. I think it is...
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      I just noticed that there is a preliminary post for this project at https://forum.pjrc.com/index.php?threads/linear-ccd-with-teensy-4-0-and-hyperspectral-imaging.72761/ I am not sure how to remove the previous, but consider this the definitive...
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      I want to add some notes of appreciation. The sketch rolls up many of the answers and help from questions that I posted to the forum at one time or another while working on this or earlier projects. Some names that come to kind include...
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      DrM replied to the thread ADC tests for TCD1304DG.
      See this, it might be help you. https://github.com/drmcnelson/Linear-CCD-with-LTSpice-KiCAD-Firmware-and-Python-Library
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      DrM replied to the thread TCD1304 with teensy 3.2.
      The new linear ccd project is posted to github, with all of the design files and source codes. Please see https://github.com/drmcnelson/Linear-CCD-with-LTSpice-KiCAD-Firmware-and-Python-Library I hope it is useful, I think it is a pretty good...
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      Just now posted to github, a repository with design files, source code and python script for sensor board using a TCD1304 and Teensy 4.0. Please see Linear CCD with design files, firmware and python The design features an instrumentation...
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      DrM replied to the thread TCD1304 with teensy 3.2.
      I am preparing a post for github with circuits and firmware for the TCD1304 with T4, and a python class library and control program. It illustrates an optimal electrical design for signal and digitization performance, and a full set of features...
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