standarddeviant

# nargoutTest.jl
function nargoutTest(a,b)
  @show a, b
  return "outp1", "outpTWO"
end

standarddeviant

# 0.6.2 in the home directory
#export JULIA_DIR="$HOME/julia-d386e40c17/"
#export JULIA_HOME="$JULIA_DIR/bin"

echo "JULIA_DIR = $JULIA_DIR"
echo "JULIA_HOME = $JULIA_HOME"
#
gcc -o wizbang -fPIC -I$JULIA_DIR/include/julia \
    -std=gnu99                                  \
    -L$JULIA_DIR/lib -L$JULIA_DIR/lib/julia     \

standarddeviant

#include <SD.h>

// START https://mcuoneclipse.com/2014/01/26/entercritical-and-exitcritical-why-things-are-failing-badly/
#define CpuCriticalVar()  uint8_t cpuSR
 
#define CpuEnterCritical()              \
  do {                                  \
    asm (                               \
    "MRS   R0, PRIMASK\n\t"             \

standarddeviant

import Plots
function Plots.plot(fc::FilterCoefficients, w=linspace(0, pi, 500); fs=2, 
                    domag=true, dophase=true, 
                    doimp=false, impn=500, 
                    dostep=false, stepn=500, size=(800, 600))
    # calculate plottable vectors
    if domag || dophase
        h = freqz(fc, w)
    end
    if doimp

standarddeviant

# using Plots
# theme(:juno)
# pyplot(size=(900, 300))
# plot(randn(10), m=:o)

using DSP
PlottableFilter = Union{FilterCoefficients}
f = digitalfilter(
    Lowpass(10, fs=40),
    Butterworth(8)

standarddeviant

standarddeviant

# gr_live_window.jl
using GR

function keyboard_channel()
    # allow 'q' and <ENTER> sequentially pressed on the keyboard to break the loop
    count = 0
    kb2loop = Channel(10)
    @async while true
        kb_input = readline(STDIN)
        # maybe we hit an error or something got messed up... 

standarddeviant

Hardware Clock Drift Measurement with Python + NTP

I've been tinkering with microcontroller code and have learned about "real time clocks" and how computers attempt to keep accurate time.

More recently, I've become loosely familiar with NTP at the UDP level and realized that I could measure the clock drift over time just by repeatedly fetching hardware time and NTP time and comparing their differences over time.

I found that my desktop machine's RTC drifted by about 6 seconds in 33 hours. This kind of error is acceptable for some applications and unacceptable for others.

I did this on a Windows 10 machine, but I first

standarddeviant

# On a normal machine, this should run just fine
# But some machines require an agressive network security policiy
# And this simple test will fail

using Sockets

TEST_PORT = 12567

# Listen asynchronously
listen_task = @async begin

standarddeviant