Appendix D: MATLAB Sample Code, from "63‐HDL64ES3 REV K", Velodyne 2013

hdl64e_s3_calib_data.m

% Matlab sample code to read calibration data from sensor output.

fileFilter = '*.pcap';
[File_name, Directory] = uigetfile(fileFilter, 'Open a .pcap file');
Filename = [Directory File_name];
fid = fopen(Filename);
ttc = fread(fid, 40);
ttc = fread(fid, 42);
ttc = fread(fid, inf, '1206*uint8=>uint8', 58);
fclose(fid);
%ttch=dec2hex(ttc);
% Determine how many data packets.
Packet = size(ttc) / 1206;
% Convert data to single precision.
S1 = single(ttc(2, :)) * 256 + single(ttc(1, :));
S2 = single(ttc(102, :)) * 256 + single(ttc(101, :));
S3 = single(ttc(202, :)) * 256 + single(ttc(201, :));
S4 = single(ttc(302, :)) * 256 + single(ttc(301, :));

for i = 0:10000 % Packets loop
    status(i + 1) = (ttc(1205 + i * 1206));
    value(i + 1) = (ttc(1206 + i * 1206));
end

a = [85 78 73 84 35]
Ind = strfind(value, a);
% Loop through 64 lasers.
for i = 1:64
    temp = single(value(Ind(1) + 64 * (i - 1) + 16:Ind(1) + 64 * (i - 1) + 16 + 7));
    temp1 = single(value(Ind(1) + 64 * (i - 1) + 32:Ind(1) + 64 * (i - 1) + 32 + 7));
    temp2 = single(value(Ind(1) + 64 * (i - 1) + 48:Ind(1) + 64 * (i - 1) + 48 + 7));
    temp3 = single(value(Ind(1) + 64 * (i - 1) + 64:Ind(1) + 64 * (i - 1) + 64 + 7));
    LaserId(i) = temp(1);
    % Add high and low bytes of Vertical Correction Factor together and check if positive or negative correction factor.
    VerticalCorr(i) = temp(3) * 256 + temp(2);
    if VerticalCorr(i) > 32768
        VerticalCorr(i) = VerticalCorr(i) - 65536;
    end
    % Scale Vertical Correction Factor by Dividing by 100.
    VerticalCorr(i) = VerticalCorr(i) / 100;
    % Add high and low bytes of Rotational Correction Factor together and check if positive or negative correction factor.
    RotationalCorr(i) = temp(5) * 256 + temp(4);
    if RotationalCorr(i) > 32768
        RotationalCorr(i) = RotationalCorr(i) - 65536;
    end
    % Scale Rotational Correction Factor by Dividing by 100.
    RotationalCorr(i) = RotationalCorr(i) / 100;
    % Add high and low bytes of remaining 2 Byte Correction Factors together and check
    % if positive or negative correction factor, if necessary.
    % Scale dimensions in mm to cm by Dividing by 10.
    % Scale Focal Slope by Dividing by 10.
    DistanceCorr(i) = (temp(7) * 256 + temp(6)) / 10;
    DistanceCorrX(i) = (temp1(2) * 256 + temp1(1)) / 10;
    DistanceCorrY(i) = (temp1(4) * 256 + temp1(3)) / 10;
    VerticalOffset(i) = (temp1(6) * 256 + temp1(5)) / 10;
    HorizonOffset(i) = (temp2(1) * 256 + temp1(7));
    if HorizonOffset(i) > 32768
        HorizonOffset(i) = HorizonOffset(i) - 65536;
    end
    HorizonOffset(i) = HorizonOffset(i) / 10;
    FocalDist(i) = temp2(3) * 256 + temp2(2);
    if FocalDist(i) > 32768
        FocalDist(i) = FocalDist(i) - 65536;
    end
    FocalDist(i) = FocalDist(i) / 10;
    FocalSlope(i) = temp2(5) * 256 + temp2(4);
    if FocalSlope(i) > 32768
        FocalSlope(i) = FocalSlope(i) - 65536;
    end
    FocalSlope(i) = FocalSlope(i) / 10;
    % Maximum and Minimum Intensity only 1 Byte each.
    MinIntensity(i) = temp2(6);
    MaxIntensity(i) = temp2(7);
end % Done with correction factors.

% Get Unit Parameter Data
s = Ind(1) char(status(s - 80:s + 6)) value(s - 80:s + 6)
Version = dec2hex(value(s - 1))
Temperature = value(s - 2)
GPS = value(s - 3)
speed = single(value(s - 48)) + single(value(s - 47)) * 256
Fov_start = single(value(s - 46)) + single(value(s - 45)) * 256
Fov_end = single(value(s - 44)) + single(value(s - 43)) * 256
warning = value(s - 13)
power = value(s - 12)
Humidity = value(s - 58)
% Done with Unit Parameters.