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  • frohr's Avatar
    06-10-2022, 08:24 AM
    frohr replied to a thread USB signal noise in General Discussion
    If I undestand well (not sure) I have to add capacitor and resistor between power of ADS / ADXL and GND = Capacitor will be connected between 5V and GND. Is that correct?
    10 replies | 447 view(s)
  • frohr's Avatar
    06-07-2022, 05:23 PM
    frohr replied to a thread USB signal noise in General Discussion
    But why is it ok with PC and not ok with notebook? Another grounding of USB in those devices? But: I will start to use my device without USB cable - could you recommend me how to send array of 30000 floats bus...
    10 replies | 447 view(s)
  • frohr's Avatar
    06-07-2022, 05:21 AM
    frohr replied to a thread USB signal noise in General Discussion
    If I connect signal generator to the connector instead ADXL the I have no noise.
    10 replies | 447 view(s)
  • frohr's Avatar
    06-06-2022, 01:21 PM
    frohr replied to a thread USB signal noise in General Discussion
    I made simple pcb where is inserted Teensy 4.0 and ADS1256. Then I have wires to connector and to ADXL1005 eval board. ADS has 2.5V reference pin - I do not use it, I think it is somehov internaly (I hope). Anyway, If...
    10 replies | 447 view(s)
  • frohr's Avatar
    06-02-2022, 04:09 PM
    Hi, I send data from adxl via ads1256 and teensy 4.0 to PC via USB. I have some issue about noise. If I connect it to PC I have OK noise. But if I connect to tablet or notebook, the noise is 10x higher. Same code, same...
    10 replies | 447 view(s)
  • frohr's Avatar
    06-01-2022, 11:39 AM
    OK, I will check. I am looking for any information but nothing what I need... Main question is: Is possible send 30000 float values from Teensy 4.0 via bluetooth in a short time? Will it be the same like via serial?
    25 replies | 994 view(s)
  • frohr's Avatar
    06-01-2022, 08:45 AM
    Hi, I try now to use bluetooth instead serial. Maybe you can help me because I have stucked. I have now very similar Teensy code: #include <SoftwareSerial.h> SoftwareSerial mySerial(0, 1); // RX, TX char...
    25 replies | 994 view(s)
  • frohr's Avatar
    05-23-2022, 05:30 PM
    Hi, I am testing it with my app in Python. But I can see lot of noise: If I have connected signal generator, I have no problem with noise and no problem witth all range of frequencies from 0-15000Hz:
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-03-2022, 07:04 PM
    But ActualSPS (30005) I need from Teensy, right? And tehre I have buffer 30000. I can not use 30005 in Python because I receive only 30k samples. Or I can add to array in Python 5 items with zero value...
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-03-2022, 06:21 PM
    Removed mean - FFT seem ok: About frequency shift: "On T4.1, I get total time of 999825 us for 30000 samples. That means sample rate = 30000/0.999825 = 30005.25" Where I have to change sample rate to...
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-03-2022, 05:48 PM
    50Hz time: FFT 50Hz:
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-03-2022, 05:35 PM
    Here is time wave for 12kHz: Zoomed: If I understand well, I have to calculate average value of all samples and then deduct this average from every sample, right?
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-03-2022, 05:03 PM
    Great. I wil test it more. Just one question - any idea why is there peak at 0Hz? It is there for all frequencies. For 12kHz: Zoomed:
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-02-2022, 08:24 PM
    Seems OK, but what do you mean about signal 12kHz and FFT 14kHz? Sine 50Hz 0.1V Sine 12000Hz 0.1V FFT 14000Hz
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-02-2022, 06:45 AM
    I have signal generator JDS6600. I have sine wave, testing from 10-7400Hz for 15kSPS and from 10-14900Hz for 30kSPS. Connected to ADS by crocodile clips. 15kSPS - signal OK in all range. 30kSPS - signal "shifted" in...
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-01-2022, 06:11 PM
    Just for comparison: "Matt Bilski" code, 30k SPS: My code, 15kSPS (but does not work 30kSPS):
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-01-2022, 04:17 PM
    Yes, seems ok, but I am not sure if the wave / time signal is ok. I want to see nice sine wave but I have: And another question - is possible make differential reading from ADXL1005? (I have eval board) ...
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-01-2022, 12:05 PM
    I have this module:
    39 replies | 1069 view(s)
  • frohr's Avatar
    05-01-2022, 06:27 AM
    How to verify that?
    39 replies | 1069 view(s)
  • frohr's Avatar
    04-30-2022, 06:21 PM
    Yes, seems the same - time signal is visually the same and fft is the same. I measured time to read 30k samples = 999731 micros - the same for both SPI speeds. I think I need 1M us. void SAMPLE_ADC() { int...
    39 replies | 1069 view(s)
  • frohr's Avatar
    04-30-2022, 06:23 AM
    I changed nothing for now - just SPI speed from 2500000 to 1950000 but the result seems the same. Then I use function read_Value() then I use: void SAMPLE_ADC() { for(int i=0;i <(BUFFER_SIZE); i++)...
    39 replies | 1069 view(s)
  • frohr's Avatar
    04-29-2022, 06:15 PM
    I am testing https://github.com/mbilsky/TeensyADS1256 I have connected function generator (JDS6600). SPS30000, PGA64, 30k samples, + to AIN0 - to AIN1. It seems to be a bit noisy. For example for 14kHz I can see in...
    39 replies | 1069 view(s)
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