Code for reading Salae oscilloscope binary dumps of analog data

This directory contains the SallyScope package which makes it easier to process analog data from a Saleae oscilloscope.

The basic function for this is readWave. Because Saleae scopes output one file per channel in a binary dump, it is common to call readWave as in the following example:

julia> using SallyScope, Glob
readWave(glob(glob"../../../test_sig_analog_?.bin")...)
2-element Vector{Any}:
 SallyScope.WaveForm(-0.0886795229756494, 0.0, 4.0e8, 1, 12598238, Float32[1.5129888, 1.4858569, 1.4817595, 1.4603738, 1.4974492, 1.4701173, 1.5102407, 1.4819095, 1.4749141, 1.4610733  …  1.4993479, 1.4710667, 1.4882553, 1.4654204, 1.4882053, 1.4559767, 1.502196, 1.4730654, 1.4871559, 1.4626722])
 SallyScope.WaveForm(-0.0886795229756494, 0.0, 4.0e8, 1, 12598238, Float32[3.2809725, 3.291279, 3.2933857, 3.3046703, 3.2890725, 3.295768, 3.2798693, 3.2944891, 3.2962444, 3.3056483  …  3.298777, 3.2820508, 3.290577, 3.293135, 3.304244, 3.2972724, 3.297072, 3.2814991, 3.2914045, 3.2954168])
julia>

The result of this is a vector of waveform structures, one for each filename argument.

In addition to support for reading waveforms, there is basic support for computing power spectra and estimating the power at particular frequencies. As an example, we can recover the magnitude of a sine wave of known frequency deeply embedded in noise:

julia> using SallyScope
julia> s500 = sin.(LinRange(0, 2π * 500, 100_000));
julia> s600 = sin.(LinRange(0, 2π * 600, 100_000));
julia> signal = SallyScope.WaveForm(0, 0, 1e5, 1, 100_000, s500 + 2 * s600 + 10.0 * randn(100_000));
julia> s = spectrum(signal, 1000)
julia> findPeaks(s, 490:5:510)
5-element Vector{Float32}:
 -20.76475
 -29.737362
  -5.8857365
 -22.244469
 -27.489155
julia> findPeaks(s, 590:5:610)
5-element Vector{Float32}:
 -27.415148
 -27.061394
  -0.30487803
 -30.2041
 -25.026798

Installation

Since this package hasn't been added to the Julia registry yet, you have to install it using the explicit GitHub URL. To do this, start Julia and run the following command:

julia> Pkg.add("https://github.com/tdunning/SallyScope.jl.git")

This will spend a few seconds compiling and you should be good to go.