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    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 cases, the more challenging it is to manage cost, size...
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    Software reboot for the T4

    @PaulStoffregen @jmarsh Thank you
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    Software reboot for the T4

    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 *)RESTART_ADDR) = (val)) void restart() {...
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    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 rate.
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    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 interference with readout and transfer, (B) matching the ADC...
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    +/-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 us taught the course. I appreciate suggestions...
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    +/-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 it if I find the time.
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    +/-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 engineers at Analog. Nonetheless, I appreciate...
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    +/-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 have been using in my lab and some are new...
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    +/-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 LT1930 and LT1931 can each provide better than...
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    +/-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 would be much better off with a +5V supply, for at...
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    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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    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 probably fast enough. @KurtE thank you, I did not...
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    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 means number of bytes? My only concern then is...
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    SPI, write 24bits?

    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. Is there a transfer24(), or better yet, a...
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    +/-5V power from USB

    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 single ended supply. But there are some designs...
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    Hamamatsu CCD Sensor (0.8 quantum efficiency) with 16bit ADC, SPI interface

    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 you want to review the design. Also, there is a...
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    Hamamatsu CCD Sensor (0.8 quantum efficiency) with 16bit ADC, SPI interface

    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 a pretty fantastic sensor and I am excited to...
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    Full feature, Instrumentation Grade Linear CCD (TCD1304) includes KiCAD, Firmware and Python

    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 post with source files, as referenced at the top...
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    Full feature, Instrumentation Grade Linear CCD (TCD1304) includes KiCAD, Firmware and Python

    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 @PaulStoffregen of course and @KurtE and @defragster...
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    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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    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 design.
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    Full feature, Instrumentation Grade Linear CCD (TCD1304) includes KiCAD, Firmware and Python

    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 grade front end that matches the CCD output to the ADC...
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    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 including clocked, triggered and gated frames and...
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    Future Teensy features & pinout

    @PaulStoffregen Yes, absolutely! I think that was this https://forum.pjrc.com/threads/72874-dual-sdo-spi I am close to finished with the design. As usual, it is about money to make the first few. After that, I plan to post it. I am pretty excited about it, it should give a lot of...
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    Future Teensy features & pinout

    Paul does not need me to say this, but I think his position is right, and I agree with Blackaddr as well. I am excited for developments in the software. The Teensy still has a lot of untapped potential. In terms of on-board features, there are always trade-offs in size, power, and cost...
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    Future Teensy features & pinout

    The Teensy 4.0 has been great. The faster USB makes a big difference and, for the analog interfaces, and I am pretty happy using the SPI with external ADCs and/or DACs (whispered: they're better). So, the T4.0/4.1 are pretty much all I need. The only thing missing so far, is that I dream...
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    Future Teensy features & pinout

    I am not sure that wifi, or ethernet, or any such need to be a part of the base board. But, it is certainly nice to have the pins available to connect those interfaces. While we're at it, what would be helpful for some of my projects, is bluetooth, as in a simple way to connect to a cell...
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    dual sdo spi

    Sure, here it is. It is titled 816x in the datasheet, the last digit is 6, 7, or 8 for speeds 250ksps, 500ksps, or 1Msps. There is an eval kit at the bottom of the page. https://www.ti.com/product/ADS8168https://www.ti.com/product/ADS8168 I meant just the dual SDO. I will probably write a...
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    dual sdo spi

    Hi, I know the question has come up a few times. But, here we are in 2023 and many analog-digitcal-converters support dual and/or quad sdo. I suppose the same might apply to sdi. It is vitally important because it makes it possible support faster data conversions in the 1Msps range and up...
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    Teensy 4.1 How to start using FlexIO?

    @KurtE HI, any chance of a simpler example? The business of routing through xbar seems a special case, from using so many pins. I could crib from what you have done, but when I get to that part I am stuck. I have no clue how to set it up when I do not need xbar. Could you possibly...
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    new design, flexio, four in, 1 out

    @PaulStoffregen, Hi Paul, thanks. The piece from miciwan, makes it seem almost easy. I think I understand how to setup the shifters. But so far I haven't see a clear description of how to set up the clock. The example in miciwan's guide, 12 bit wide parallel, is far too complicated to be...
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    Teensy 4.1 How to start using FlexIO?

    @miciwan I just read your document on the wiki for the third time. It's great, really super helpful. But, do you have some examples other than the 12 bit wide transfer? It would be great if you could perhaps start with the simplest example, one pin input for some different word sizes, say...
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    new design, flexio, four in, 1 out

    Hi, I am about to start a new design using the Teensy 4.0. I would like to ask and double check that it is realistic and feasible. The board will have four ADC's and one DAC. The five devices would be connected to five pins. They clock would go to all five in parallel. So, we would...
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    T4 FlexIO SPI clock

    @Paul Thank you. So, any way it turns out to be yet another part that is not available.
  36. D

    T4 FlexIO SPI clock

    Well, I just checked it is also not yet available.
  37. D

    T4 FlexIO SPI clock

    @jmarsh Thank you, that of course makes perfect sense. It's video. I was thinking only about the spi interface. The original question was to try to increase the limit on the FlexIO SPI from 30MHz. Here is a new ADC that I am really excited about, https://www.ti.com/product/ADS9218 It's...
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    T4 FlexIO SPI clock

    Ahh, of course. Toooo simple. And yet, why not just enter a frequency and let it figure it out? Some other lower level call like set_clk_(..) can get the nitty gritty. Thank you.
  39. D

    T4 FlexIO SPI clock

    @jmarshm, oh, ok, great, thank you. What are the ranges of values for num and den? is there a particular meaning for the names num and den that would help me understand the code?
  40. D

    T4 FlexIO SPI clock

    @jmarsh Thank you, The call set_ck() seems like it might do it, but it is entangled with the video controls. Do you have an example code that only sets the clock? Or putting it another way, for the call from @KurtE , to set a given frequency, what are the settings for clk_sel, uint8_t...
  41. D

    T4 FlexIO SPI clock

    @KurtE In KurtE's FlexIO page at github, it seems to say the default clock rate for the FlexIO is 30MHz. And, it offers the following which seems to change the master clock for the FlexIO. void setClockSettings(uint8_t clk_sel, uint8_t clk_pred, uint8_t clk_podf); It seems like these...
  42. D

    T4 FlexIO - Looking back at my T4 beta testing library FlexIO_t4

    I meant to ask, is FlexIOSPI working? I found the library on github.
  43. D

    Linear CCD with Teensy 4.0 and Hyperspectral Imaging

    This is a single board that hosts a linear CCD with analog front end and a Teensy 4.0. The analog section provides shift, invert and gain to match the full swing (dark to saturation) from the CCD to the input range of the 12 bit ADC of the Teensy 4.0, while isolating the gain section from part...
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    Spectrometer board set

    This a two board solution for a CCD spectrometer. The mother board hosts a Teensy 4.0 with a differential receiver and 16-bit ADC. There is a daughter card for each of the supported Linear CCDs (Toshiba, Sony, Hamamatsu) with an analog section and logic conversion for that specific sensor...
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    T4 FlexIO - Looking back at my T4 beta testing library FlexIO_t4

    So, what is the status of the FlexIOSPI? What is the maximum speed for FlexIOSPI? What is the setup time for each transfer? Thank you (Referring to earlier posts in this thread, yes the SPI with ADC is running at 30MHz. Thank you again to everybody who helped. Since the datasheets...
  46. D

    Some questions on LittleFS and program memory for the T4

    Hi Paul, I just tried it with 1024*1024, and that works. It seems there is a minimum size that it needs. Can that be added to the documentation?
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    Some questions on LittleFS and program memory for the T4

    And when I set DATALENGTH * 1024, I get the filesys not ready message, probably because it is too big.
  48. D

    Some questions on LittleFS and program memory for the T4

    Hmmm. how interesting. The original code was DATALENGTH * 2 + 1024. The intent was one buffer and another 1K for overhead..
  49. D

    Some questions on LittleFS and program memory for the T4

    I just modified the program to load some values into the buffer, for the write() and then to zero the buffer before the read(). With that I can confirm that as far as read is concerned, the data was nt0 stored or read back from the file.
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