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      strud reacted to DrM's post in the thread T4 interrupt latency and etc with Like Like.
      @PaulStoffregen Thank you Paul, that is super helpful. I really appreciate it, I think you have saved me a lot of time. Fantastic.
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      Hi Gef Those expansion devices over I2C will not be much good at all for analog signals. They are really suitable for low speed digital IO. There are SPI versions of these devices available that can obviously increase the update bandwidth...
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      Hi bigdlin, For a data point, my board has no issue running the SPI clock at 50MHz for the ADC I'm using with a Teensy 4.1.
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      This seems very curious and not the norm: Typically the SPI bus is shared and additional CS lines are used to select the chip you want to talk to. Why are they doing it this way? bigDlin do you have them wired this way? Is it working? Also I...
      • Screenshot 2024-02-08 153805.jpg
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      That chip produces 16 bit results ie 16bit multiplexed ADC.
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      Is the data actually 32bits? or is it a 24bit converter sending a 4byte result? Depending on the converter, some will allow the result (eg ADC) to be sent as 3 bytes (24bits) instead of the 32 saying you 25% throughput.
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      strud replied to the thread Need advice on PCB manufacturers.
      I had been using PCBWay for everything up until recently when they dramatically increased their pricing on 4 layer boards. A 100mm x 100mm 4 layer board from PCB Way is about 4 to 5 times the price of the same design from JLCPCB which I found...
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      strud reacted to joepasquariello's post in the thread Non blocking writes to sd card with Like Like.
      SdFat is blocking for both read and write. There is a fairly recent thread where someone modified SdFat to do non-blocking reads, but not writes. There is a way, though, to limit blocking times to 5-6 us and avoid the very long blocking times of...
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      strud replied to the thread Writing Data to Teensy 4.1 microSD.
      Looking at your loop, it seems that you will keep opening and writing to your file indefinitely. Is that why you have append as an option/mode?
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      strud replied to the thread [no Teensy?] +/-5V power from USB.
      Hi DrM My ADC input full range is only +-1.2V hence the +-4V is plenty of room. I am using these as my front end buffer amplifiers. They are working very well in my current application...
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      yeah that would be nice as well. Honestly anything at this point would be a game changer. I'm currently developing a fairly large program for a teensy 4.1 with freeRTOS and the software debugger (https://github.com/ftrias/TeensyDebug) just...
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      strud replied to the thread [no Teensy?] +/-5V power from USB.
      Hi DrM Looking good. How much current and at what voltage ripple are you getting out of your design? I have now used a charge pump device to do something similar but with 5V input and +-4V outputs. I have a DAQ board which requires a bipolar...
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      strud reacted to DrM's post in the thread [no Teensy?] +/-5V power from USB with Like Like.
      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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      One thing to think over is that the Teensy 4.1 is not 5V tolerant so if at some time you have accidentally pulled up to 5V maybe you have damaged the I2C bus IO on the Teensy? Do you have an DSO or logic analyser to look at the signals?
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      That looks correct. However one issue you need to be very careful of is ensuring that SDA and SCL are not pulled up to or being driven to 5V. Is your ADC running off 3.3 or 5V?
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      They can also save the cost of providing technical support by tricking their customers into asking you for support. If your product becomes successful enough that it's resold through dealers or distributors, then you'll have a very difficult...
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      In my working system I used the address 0x48, 0x49 etc
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      Good points there Collin :-)
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      Hi Paul, I don't have any issue with the process you have created at all. My question for the forum is how important people feel it is to use this for a product that is going out to consumers. One thing that does weigh into this a little is the...
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      Hi Smuscat, Recommend you look at the pullup resistors as well (not sure if you have done so?) Are your connections made to the SDA0 and SCL0 pins? This is important as you have not defined pins other than default in your code. I also not that...
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      Hey Mark, Thanks for your considered response. Your product sounds very nice! I can see for products that have actuators or potential safety issues then preventing other versions of firmware from being loaded is a very good reason to enable...
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      I have a product I've developed for which I use the Teensy 4.1, it is a data acquisition and related product. I was initially planning to provide these with the locked version of the Teensy 4.1 so I could prevent people from copying the firmware...
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      Hi smuscat, I have done this exact thing recently and managed to have it working well now. I would check that you have appropriate pull up resistors on the I2C lines. I had 4k7 resistors and was running a clock freq of 400kHz and with the length...
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      I have used these in a few projects and use the output do supply a buck converter that supplies 5V to my board including the Teensy 4.1 https://www.digikey.com.au/en/products/detail/abracon-llc/ARJM11D7-114-AB-EW2/7675220 One could design a...
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