MATLAB在app中扫描串口并在下拉菜单中显示

更新

经评论提醒，R2019已有现成APIhttps://ww2.mathworks.cn/help/matlab/ref/serialportlist.html

背景故事

要在MATLAB的App里面动态识别有什么串口, 放在下拉菜单里让用户选择.

实现串口扫描

这是网上找的代码:
放在同一目录内, 创建一个.m文件:IdentifySerialComs.m.

function devices = IdentifySerialComs()

devices = [];

Skey = 'HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\SERIALCOMM';
[~, list] = dos(['REG QUERY ' Skey]);
if ischar(list) && strcmp('ERROR',list(1:5))  %% strcmp 两个字符串相同返回1
    disp('Error: EnumSerialComs - No SERIALCOMM registry entry')
    return;
end
list = strread(list,'%s','delimiter',' '); %#ok requires strread()
coms = 0;
for i = 1:numel(list)  %%numel 返回元素个数
    if strcmp(list{i}(1:3),'COM')
        if ~iscell(coms)
            coms = list(i);
        else
            coms{end+1} = list{i}; %#ok Loop size is always small
        end
    end
end
out = 0;
outK = 0;
for j=1:2
    switch j
        case 1
            key = 'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\USB\';
        case 2
            key = 'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\FTDIBUS\';
    end
    [~, vals] = dos(['REG QUERY ' key ' /s /f "FriendlyName" /t "REG_SZ"']);
    if ischar(vals) && strcmp('ERROR',vals(1:5))
        disp('Error: EnumSerialComs - No Enumerated USB registry entry')
        return;
    end
    vals = textscan(vals,'%s','delimiter','\t');
    vals = cat(1,vals{:});
    for i = 1:numel(vals)
        if strcmp(vals{i}(1:min(12,end)),'FriendlyName')
            if ~iscell(out)
                out = vals(i);
            else
                out{end+1} = vals{i}; %#ok Loop size is always small
            end
            if ~iscell(outK)
                outK = vals(i-1);
            else
                outK{end+1} = vals{i-1}; %#ok Loop size is always small
            end
        end
    end
end

i_dev=1;Sservices=[];
for i = 1:numel(coms)
    match = strfind(out,[coms{i},')']);
    ind = 0;
    for j = 1:numel(match)
        if ~isempty(match{j})
            ind = j;
            [~, sers] = dos(['REG QUERY "' outK{ind} '" /f "Service" /t "REG_SZ"']);
            sers = textscan(sers,'%s','delimiter','\t');
            sers = cat(1,sers{:});
            if (numel(sers)>1)
                sers=strread(sers{2},'%s','delimiter',' ');
                Sservices{i_dev} = sers{3};
                i_dev=i_dev+1;
            end
        end
    end
end
Sservices=unique(Sservices);

i_dev=1;
for ss=1:numel(Sservices)
    key = ['HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\' Sservices{ss} '\Enum'];
    [~, vals] = dos(['REG QUERY ' key ' /f "Count"']);
    if ischar(vals) && strcmp('ERROR',vals(1:5))
        %         disp('Error: EnumSerialComs - No Enumerated services USB registry entry')
        %         return
    end
    vals = textscan(vals,'%s','delimiter','\t');
    vals = cat(1,vals{:});

    if (numel(vals)>1)
        vals=strread(vals{2},'%s','delimiter',' ');
        Count=hex2dec(vals{3}(3:end));
        if Count>0
            [~, vals] = dos(['REG QUERY ' key]);
            vals = textscan(vals,'%s','delimiter','\t');
            vals = cat(1,vals{:});
            out=0;
            j=0;
            for i = 1:numel(vals)
                Enums=strread(vals{i},'%s','delimiter',' ');
                try nums=hex2dec(Enums{1});
                catch
                    nums=-1;
                end
                if(nums==j)
                    out=['HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\' Enums{3}];
                    [~, listC] = dos(['REG QUERY "' out '" /s /f "PortName" /t "REG_SZ"']);
                    listC = textscan(listC,'%s','delimiter','\t');
                    listC = cat(1,listC{:});
                    if (numel(listC)>1)
                        listC=strread(listC{2},'%s','delimiter',' ');
                        for i = 1:numel(coms)
                            if strcmp(listC{3},coms{i})
                                [~, NameF] = dos(['REG QUERY "' out '" /s /f "FriendlyName" /t "REG_SZ"']);
                                NameF = textscan(NameF,'%s','delimiter','\t');
                                NameF = cat(1,NameF{:});
                                com = str2double(coms{i}(4:end));
                                if com > 9
                                    length = 8;
                                else
                                    length = 7;
                                end
                                devices{i_dev,1} = NameF{2}(27:end-length); %#ok
                                devices{i_dev,2} = com; %#ok Loop size is always small
                                i_dev=i_dev+1;
                            end
                        end
                    end
                    j=j+1;
                end
            end
        end
    end
end

end

App中的操作

先添加两个私有属性的变量:

properties (Access = private)
    scan_coms; % 串口列表
    com_num;   % 串口设备数量
end

在合适的位置插入一个下拉框和按钮, 添加按钮的回调函数, 内容如下.

% Button pushed function: Button
function ButtonPushed(app, event)
    app.scan_coms = IdentifySerialComs;
    %app.DropDown.Items = '';
    app.com_num = size(app.scan_coms);
    for ii = 1: app.com_num(1)
        app.DropDown.Items(ii) =  strcat(app.scan_coms(ii, 1),'@COM',  num2str(cell2mat(app.scan_coms(ii, 2)))); 
    end
    
end

这样子就好了, 就实现了点击按钮之后列表中的内容随串口变化.