%{
See this site for info on how to connect to
serial pots in matlab:
https://www.mathworks.com/help/matlab/ref/serialport.html
NOTE: This should be called after flashing "setup.c"
%}
% Creates the Photon class with all usual Photon commands inside. Added on
% code to help connect via Serial.
classdef Photon < IP_Photon
% Gets properties of Photon (name, access token, and port)
properties (SetAccess = protected, GetAccess = private)
port;
p_serial;
p_cleaner;
end
properties (Constant)
%{
This is a set of constants that link a photon side function
to an integer.
%}
f_CONNECT = 1;
f_GETPINMODE = 2;
f_ISCONNECTED = 3;
f_SETINPUT = 4;
f_SETOUTPUT = 5;
f_ANALOGREAD = 6;
f_DIGITALREAD = 7;
f_ANALOGWRITE = 8;
f_DIGITALWRITE = 9;
f_GETPIN = 10;
f_DISCONNECT = 11;
end
methods
% Creates Photon object
function obj = Photon(name, accesstoken, port)
obj = obj@IP_Photon(name, accesstoken);
% If port isn't given, turn off usb functionality
if nargin == 2
port = '';
end
if strcmp(strtrim(port), '')
% tell the student usb functionality is off
warning(strcat('No port was given when creating this photon object; ',...
'MATLAB will not be able to communicate with your photon through usb.'));
% set the port to 'NOPORT' so MATLAB knows not to use usb
obj.port = 'NOPORT';
elseif nargin == 3
obj.port = port;
% Check if the serial port is already open
ports = instrfind('Port', port);
if length(ports)
for p = ports
if strcmp(p.Status, 'open') & Photon.valid(p)
obj.p_serial = p;
break;
end
end
end
% make sure the photon is connected to a valid prot
obj.serial_reconnect()
% Assume you want to connect to the internet, since its not experimental
obj.connect();
end
end
% Gets rid of object and closes the port.
function delete(obj)
try
p = obj.p_serial;
% stop all communication
w = warning('off', 'instrument:stopasync:invalid'); % suppresses a warning that keeps coming up
stopasync(p);
warning(w); % turns the warning back on
% fully close the port
fclose(p);
delete(p);
catch ME
% ignore errors if obj.p_serial either was not initialized or was unable to connect
if strcmp(ME.identifier, 'MATLAB:serial:get:invalidOBJ')
% ignore
elseif strcmp(ME.identifier, 'MATLAB:serial:stopasync:opfailed')
% ignore
elseif strcmp(ME.identifier, 'MATLAB:UndefinedFunction')
% ignore
else
% don't ignore other errors
rethrow(ME);
end
end
end
% Try connect to the cloud, Returns true if able, false otherwise
function resp = connect(obj)
if ~obj.isConnected()
fwrite(obj.p_serial, obj.f_CONNECT, "uint8");
while ~obj.p_serial.BytesAvailable
pause(1);
end
end
resp = obj.isConnected();
resp = obj.isConnected();
end
% Disconnect from wifi, Returns true if able, false otherwise
function resp = disconnect(obj)
if obj.isConnected() & ~strcmp(obj.port, 'NOPORT')
fwrite(obj.p_serial, obj.f_DISCONNECT, "uint8");
while ~obj.p_serial.BytesAvailable
pause(1);
end
end
resp = ~obj.isConnected();
end
%{
Returns true if the photon is connected to the cloud,
false otherwise.
NOTE: if MATLAB can't use usb, this returns true.
%}
function resp = isConnected(obj)
% set resp to true by default, that way, if the photon is not connected by
% usb, isConnected tells the other methods to use the cloud
resp = true;
% Check if connected
if ~strcmp(obj.port, 'NOPORT')
% Make sure it is valid
if ~Photon.valid(obj.p_serial)
obj.serial_reconnect();
end
% Clear the serial in
if obj.p_serial.BytesAvailable
fread(obj.p_serial, obj.p_serial.BytesAvailable, "uint8");
end
% ask the photon if it is connected to wifi
fwrite(obj.p_serial, obj.f_ISCONNECTED, "uint8");
if ~fread(obj.p_serial, 1, "uint8")
% photon is not connected to cloud, return false
resp = false;
end
end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%{
The following functions are implmented for both usb and the cloud.
Each one follows the following general process:
- checks if the object is connected to the internet w/
obj.isConnected(). If so, it calls the internet version
- else:
- sends a byte from the list of constants on lines 32 to 42
that tells the photon what command to run
- reads a byte response from the photon, stores the byte in
the feedback variable so it can be returned
Any extra operations are the same as the ones in the original photon
(now IP_Photon).
%}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Returns the pin mode (input or output) of pin and prints its mode
function feedback = getPinMode(obj,pin)
if obj.isConnected()
feedback = getPinMode@IP_Photon(obj, pin);
else
% Send the command and arg to the photon
fwrite(obj.p_serial, [obj.f_GETPINMODE, double(pin)], "uint8");
% Get & use the response
feedback = fread(obj.p_serial, 1, "uint8");
if feedback == 1
fprintf('INPUT\n')
else
fprintf('OUTPUT\n')
end
end
end
%setInput pin
function feedback = setInput(obj,pin)
if obj.isConnected()
feedback = setInput@IP_Photon(obj, pin);
else
% Send the command and arg to the photon
fwrite(obj.p_serial, [obj.f_SETINPUT, double(pin)], "uint8");
% Get & use the response
feedback = fread(obj.p_serial, 1, "uint8");
end
end
%setOuput pin
function feedback = setOutput(obj,pin)
if obj.isConnected()
feedback = setOutput@IP_Photon(obj, pin);
else
% Send the command and arg to the photon
fwrite(obj.p_serial, [obj.f_SETOUTPUT, double(pin)], "int8");
% Get & use the response
feedback = fread(obj.p_serial, 1, "int8");
end
end
% Reads the value of an analog pin returning a value of 0-3.33V
function feedback = analogRead(obj,pin)
if obj.isConnected()
feedback = analogRead@IP_Photon(obj, pin);
else
% Make sure its an input pin
obj.setInput(pin);
% Send the command and arg to the photon
fwrite(obj.p_serial, [obj.f_ANALOGREAD, double(pin)], "uint8");
% Get & use the response
feedback = fread(obj.p_serial, 1, "uint16"); %Read in as bit value
feedback = feedback .* 3.33 ./ 2^12; %Convert from 12 bit value
end
end
% Reads the value of a digital pin
function feedback = digitalRead(obj,pin)
if obj.isConnected()
feedback = digitalRead@IP_Photon(obj, pin);
else
% Make sure its an input pin
obj.setInput(pin);
% Send the command and arg to the photon
fwrite(obj.p_serial, [obj.f_DIGITALREAD, double(pin)], "uint8");
% Get & use the response
feedback = fread(obj.p_serial, 1, "uint8");
end
feedback = (feedback ~= 0) * 1
end
% Writes an analog voltage value to an analog pin
function feedback = analogWrite(obj,pin,value)
if obj.isConnected()
feedback = analogWrite@IP_Photon(obj, pin, value);
else
if strcmp('A3', pin) || strcmp ('A6', pin)
if value<0.0 || value>3.33
warning('Analog voltage set outside range (0 to 3.33 V)!')
else
value = round(value .* 4095./3.33); %Convert to 8 bit value
% Make sure its an output pin
obj.setOutput(pin);
% Send the command and arg to the photon
fwrite(obj.p_serial, [obj.f_ANALOGWRITE, double(strcat(pin,',',int2str(value)))], "uint8");
% Get & use the response
feedback = fread(obj.p_serial, 1, "uint8"); %Read in as bit value
if (obj.p_serial.BytesAvailable)
feedback = bitshift(feedback, 8) + fread(obj.p_serial, 1, "uint8");
end
end
else
if value<0.0 || value>3.33
warning('Analog voltage set outside range (0 to 3.33 V)!')
else
value = round(value .* 255./3.33); %Convert to 8 bit value
% Make sure its an output pin
obj.setOutput(pin);
% Send the command and arg to the photon
fwrite(obj.p_serial, [obj.f_ANALOGWRITE, double(strcat(pin,',',int2str(value)))], "uint8");
% Get & use the response
feedback = fread(obj.p_serial, 1, "uint8"); %Read in as bit value
if (obj.p_serial.BytesAvailable)
feedback = bitshift(feedback, 8) + fread(obj.p_serial, 1, "uint8");
end
end
end
end
feedback = feedback .* 3.33 ./ 255; % convert from 12 bit value
end
% Writes a 0 or 1 value to a digital pin
function feedback = digitalWrite(obj,pin,value)
if obj.isConnected()
feedback = digitalWrite@IP_Photon(obj, pin, value);
else
% Make sure its an output pin
obj.setOutput(pin);
% Send the command and arg to the photon
fwrite(obj.p_serial, [obj.f_DIGITALWRITE, double(strcat(pin,',',int2str(value)))], "uint8");
% get & use the response
feedback = fread(obj.p_serial, 1, "uint8");
end
end
%Returns the number that corresponds to pin. (ex: D7=7, A7=17)
function feedback = getPin(obj,pin)
if obj.isConnected()
feedback = getPin@IP_Photon(obj, pin);
else
% Send the command and arg to the photon
fwrite(obj.p_serial, [obj.f_GETPIN, double(pin)], "uint8");
% Get & use the response
feedback = fread(obj.p_serial, 1, "uint8");
end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%{
Check IP_Photon for unimplemented methods. Each of those may be used
with the cloud but not without.
%}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%{
These are usb specific methods.
%}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
methods (Access = private)
% Reconnects this photon object to the photon's serial port
function serial_reconnect(obj, varargin)
% Check if can use usb
if ~strcmp(obj.port, 'NOPORT')
% look for an existent, valid port connected to the photon
ports = instrfind('Port', obj.port);
val = false;
if ismember(obj.p_serial, ports)
val = Photon.valid(obj.p_serial);
end
% if no valid port exists, create a new one
if ~val
% Delete any invalid connections to the port
instrreset;
% Reopen the port
obj.p_serial = serial(obj.port);
obj.p_serial.BaudRate = 9600;
fopen(obj.p_serial);
end
end
end
end
methods (Static)
% Returns true if p is a valid serial port, false otherwise
% NOTE: this is used rather than isvalid(p) because in testing
% isvalid() would return true when p was not valid
function b = valid(p)
b = false;
try
p.BytesAvailable;
b = true;
catch ME
% ignore errors that tell you p is invalid
if ~strcmp(ME.identifier, 'MATLAB:serial:get:invalidOBJ')
% ignore
elseif strcmp(ME.identifier, 'MATLAB:structRefFromNonStruct')
% ignore
else
% throw anything else
rethrow(ME);
end
end
end
end
end