tfcb

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Posts posted by tfcb

    Pmod ISNS20 SPI Arduino

    in Add-on Boards

    Posted

    On 4/2/2019 at 10:52 AM, JColvin said:

    Hi @tfcb,

    I am taking a look into this; I connected a level shifter of my own (Digilent's Pmod LVLSHFT rather than the Sparkfun one you linked to) to connect an Arduino Uno and Pmod ISNS20, but I too am getting strange values (no initial offset for example), so I'm debugging some more.

    Thanks,
    JColvin

     @JColvin,

    Any update on this? Still hoping to use the modules.

    Thanks,

    Tim

    Pmod ISNS20 SPI Arduino

    in Add-on Boards

    Posted

    Hi,

    Just tested the latest update. Here is the output with nothing connected to the IP connector.  Since I'm using a Arduino Uno a https://www.sparkfun.com/products/12009 is inline to deal with 5V vs 3.3V. Any thoughts I what I might be doing wrong?

    Thanks!

    Tim 

    15:06:29.519 -> 13553 mA   |  15.83 A
15:06:29.519 -> 
15:06:29.553 -> 
15:06:29.623 -> 16967 mA   |  18.10 A
15:06:29.623 -> 
15:06:29.623 -> 
15:06:29.726 -> 13550 mA   |  12.41 A
15:06:29.726 -> 
15:06:29.726 -> 
15:06:29.829 -> 12411 mA   |  11.27 A
15:06:29.829 -> 
15:06:29.829 -> 
15:06:29.931 -> 11274 mA   |  11.27 A
15:06:29.931 -> 
15:06:29.931 -> 
15:06:30.033 -> 11274 mA   |  11.27 A
15:06:30.033 -> 
15:06:30.033 -> 
15:06:30.136 -> 11275 mA   |  12.41 A
15:06:30.136 -> 
15:06:30.136 -> 
15:06:30.238 -> 15823 mA   |  18.10 A
15:06:30.238 -> 
15:06:30.238 -> 
15:06:30.341 -> 19237 mA   |  14.69 A
15:06:30.341 -> 
15:06:30.341 -> 
15:06:30.441 -> 13552 mA   |  12.41 A
15:06:30.441 -> 
15:06:30.475 -> 
15:06:30.543 -> 11274 mA   |  11.27 A
15:06:30.543 -> 
15:06:30.577 -> 
15:06:30.645 -> 11274 mA   |  11.27 A
15:06:30.645 -> 
15:06:30.679 -> 
15:06:30.748 -> 11274 mA   |  11.27 A
15:06:30.748 -> 
15:06:30.782 -> 
15:06:30.850 -> 11274 mA   |  12.41 A
15:06:30.850 -> 
15:06:30.884 -> 
15:06:30.953 -> 15820 mA   |  15.82 A
15:06:30.953 -> 
15:06:30.986 -> 
15:06:31.055 -> 15824 mA   |  13.55 A
15:06:31.055 -> 
15:06:31.089 -> 
15:06:31.157 -> 12415 mA   |  11.27 A
15:06:31.157 -> 
15:06:31.191 -> 
15:06:31.259 -> 11274 mA   |  11.27 A
15:06:31.259 -> 
15:06:31.293 -> 
15:06:31.361 -> 11274 mA   |  11.27 A
15:06:31.361 -> 
15:06:31.395 -> 
15:06:31.464 -> 11274 mA   |  11.28 A
15:06:31.464 -> 
15:06:31.499 -> 
15:06:31.567 -> 13547 mA   |  12.41 A
15:06:31.567 -> 
15:06:31.601 -> 
15:06:31.669 -> 19238 mA   |  16.97 A
15:06:31.669 -> 
15:06:31.703 -> 
15:06:31.771 -> 16969 mA   |  13.55 A
15:06:31.771 -> 
15:06:31.805 -> 
15:06:31.873 -> 11274 mA   |  11.27 A
15:06:31.873 -> 
15:06:31.907 -> 
15:06:31.975 -> 11274 mA   |  11.27 A
15:06:31.975 -> 
15:06:32.009 -> 
15:06:32.079 -> 11274 mA   |  11.27 A
15:06:32.079 -> 
15:06:32.114 -> 
15:06:32.182 -> 11274 mA   |  11.28 A
15:06:32.182 -> 
15:06:32.215 -> 
15:06:32.283 -> 11274 mA   |  12.42 A

     

    Pmod ISNS20 SPI Arduino

    in Add-on Boards

    Posted

    I ran the supplied code on an Arduino Uno using a level shifter. The output doesn't make any sense to me. Why are the mA and A results so different? Based on the use of a DMM the A should be approx 13.

    Given the for loop wouldn't work on Arduino 1.8.8 I'm wondering if anyone has ever used this part successfully. I appreciate your insight on getting this to work.

    Quote


    21:03:59.722 -> -3 mA   |  14.91 A
    21:03:59.790 -> -17 mA   |  15.74 A
    21:03:59.824 -> 27 mA   |  16.07 A
    21:03:59.894 -> 16 mA   |  15.56 A
    21:03:59.928 -> 21 mA   |  13.81 A
    21:03:59.996 -> -37 mA   |  10.92 A
    21:04:00.029 -> -34 mA   |  7.39 A
    21:04:00.099 -> 3 mA   |  -21.73 A
    21:04:00.133 -> 14 mA   |  -24.97 A
    21:04:00.200 -> -7 mA   |  -15.56 A
    21:04:00.234 -> -5 mA   |  -18.75 A
    21:04:00.302 -> -22 mA   |  -24.99 A
    21:04:00.336 -> 3 mA   |  -25.01 A
    21:04:00.404 -> 18 mA   |  -20.24 A
    21:04:00.439 -> 31 mA   |  -21.51 A
    21:04:00.508 -> -10 mA   |  -22.08 A
    21:04:00.541 -> 8 mA   |  -22.66 A
    21:04:00.609 -> 1 mA   |  -22.27 A
    21:04:00.643 -> -35 mA   |  -21.73 A
    21:04:00.713 -> -10 mA   |  -12.20 A
    21:04:00.747 -> -33 mA   |  -8.29 A
    21:04:00.781 -> 37 mA   |  -4.85 A
    21:04:00.850 -> -27 mA   |  -1.34 A
    21:04:00.884 -> 28 mA   |  2.17 A
    21:04:00.952 -> -4 mA   |  5.09 A
    21:04:00.987 -> 10 mA   |  7.94 A
    21:04:01.056 -> 6 mA   |  10.27 A
    21:04:01.090 -> -11 mA   |  12.49 A
    21:04:01.159 -> -32 mA   |  14.11 A
    21:04:01.193 -> 37 mA   |  15.23 A
    21:04:01.261 -> -25 mA   |  15.91 A
    21:04:01.296 -> -15 mA   |  16.01 A
    21:04:01.364 -> 7 mA   |  15.20 A
    21:04:01.398 -> -28 mA   |  13.04 A

     

     

    Pmod ISNS20 SPI Arduino

    in Add-on Boards

    Posted · Edited by tfcb

    Are the data lines on the ISNS20 5v tolerant? The "resource center" isn't exactly clear. From what I can tell the various data lines on the Arduino Uno are all 5v.  Obviously 3.3v will be provided to VCC. Thanks.

    BTW, as I understand, this for statement:  

    for(int i; i < NUM_READINGS; i++)

    should really be: 

    for(int i=0; i < NUM_READINGS; i++)

    otherwise, the for loop might only run once (if lucky) as the variable "i" is undefined on the first run and might remain >= NUM_READINGS thereafter. The same version of gcc produces different results when executed on ARM or x86_64. More details than I understand at: https://stackoverflow.com/questions/4532871/define-integer-int-whats-the-default-value

     

    Pmod ISNS20 SPI Arduino

    in Add-on Boards

    Posted · Edited by tfcb

    FWIW, the following python program, based on this code: https://github.com/DesignSparkrs/DesignSpark.Pmod/blob/master/DesignSpark/Pmod/ISNS20.py 

    #!/usr/bin/python

import spidev
import time

spi = spidev.SpiDev()
spi.open(0, 0)
spi.max_speed_hz = 100000
spi.mode = 0b00
try:
    while True:
        resp = spi.xfer2([0x00, 0x00])
        w = resp[0]
        w <<= 8
        w |= resp[1]
        refV = 3.3
        lsb = refV/4096
        mV= (w-2048)*lsb*1000
        amps = mV/66
        print amps
        time.sleep(1)
except KeyboardInterrupt:# Ctrl+C pressed, so...
    spi.close()

    produces: 

    -0.048828125
15.2221679687
16.1010742188
13.76953125
5.50537109375
-3.6376953125
-11.2182617188
-15.4296875
-15.576171875
-8.69140625
1.025390625
9.89990234375
14.8559570312
15.7836914062
9.0087890625
-1.318359375
-10.595703125
-0.048828125
-0.048828125

     

    Pmod ISNS20 SPI Arduino

    in Add-on Boards

    Posted

    Hi,

    I'm attempting to use the ISNS20 with an Arduino Uno. I am using a Sparkfun Bi-Directional Logic Level Converter to handle 5V vs 3.3V.

    I'm using the source from https://www.hackster.io/58702/using-the-pmod-isns20-with-arduino-uno-0ee8db .

    CS is connected to Pin 10, D0 is connected to Pin 12 and CLK is Pin 13.

    I wire Black/Line to IP+ and the IP- to the Black/Line connection on an outlet. Unfortunately I get the same result if I draw current or not (using a hair dryer).

    14:54:37.548 -> Courant=-33 mA
    14:54:37.582 -> Courant=28 mA
    14:54:37.582 -> Courant=-33 mA
    14:54:37.615 -> Courant=-33 mA
    14:54:37.615 -> Courant=28 mA
    14:54:37.648 -> Courant=-33 mA

    I don't have an oscilloscope. I do have a DMM.

    Thanks,

    Tim