Changeset 100

Timestamp:

06/24/08 17:23:27 (5 years ago)

Author:

atorf

Message:

Added simple Accelerator demo, improved basic functions

Location:

branches

Files:

• atorf/USB_ToolboxTest_Windows/NXT_LSRead.m (modified) (1 diff)
• behrens/RWTHMindstormsNXT/SendMotorSettings.m (modified) (2 diffs)
• workshop/Accelerator/AcceleratorTest2_USB.m (added)
• workshop/Accelerator/AcceleratorTest3_USB.m (added)
• workshop/Accelerator/GetAccelerator.m (modified) (4 diffs)

branches/atorf/USB_ToolboxTest_Windows/NXT_LSRead.m

@@ -169 +169 @@
 
 BytesRead = content(1);
+
+%TODO see below
+%FIXME fix outputting uint8, convert to double first!
+
 % avoid index out of bounds
 tmpEnd = min(BytesRead + 1, length(content));

branches/behrens/RWTHMindstormsNXT/SendMotorSettings.m

@@ -1 +1 @@
 function SendMotorSettings(f_port, f_power, f_angle, f_speed, f_sync, f_ratio, f_ramp)
-% Sends previously specified settings to current active motor.
+% Sends previously specified settings to the currently active motor.
 %  
 % Syntax
@@ -19 +19 @@
 %
 % Note:
-%   All settings like power, angle limit and so on, will only take effect once you send them to the
-%   motor using THIS function. Note that if you have synced two motors together, this function
+%   All settings like power, angle limit, and so on, will only take effect once you send them to the
+%   motor using THIS function. Note that if you have synced two motors together this function
 %   internally sends two packets to both the motors. This is required, but you can work as if this
 %   was just one command.

branches/workshop/Accelerator/GetAccelerator.m

@@ -4 +4 @@
     %-----------------------------LSWRITE----------------------------------
 
-    % create this I2C command. basically all we want to do is request 1
-    % byte, the current sensor reading!
+    % create this I2C command. basically all we want to do is request 6
+    % bytes, the current sensor reading!
     
     RequestLen = 6;
-    I2Cdata = hex2dec(['02'; '42']); % Read Measurement Byte 0 (see LEGO Mindstorms NXT 
-                                     % Ultrasonic Sensor - I2C Communication Protocol)
+    I2Cdata = hex2dec(['02'; '42']); 
     
         NXT_LSWrite(f_sensorport, RequestLen, I2Cdata, 'dontreply')
@@ -23 +22 @@
     % should never get ready...
     
+    %instead of "wasting time" in the idle loop below, waiting for the
+    %sensor to get ready, we could also just wait some time here and
+    %collect the sensor bytes then...
+    %pause(0.015);
+    
+    
     BytesReady = 0;
-    while (BytesReady == 0)
-        %TODO some sort of timeout in here in case we never get an answer?
+    ticID = 34; %fixme randomly, dangerous
+    timeout = 2; % in s
+    tictic(ticID); 
+    status = -1;
+    %idlecount = 0;
+    while ((BytesReady < 6) ||  (status ~= 0)) && (toctoc(ticID) < timeout)
+        
         [BytesReady status] = NXT_LSGetStatus(f_sensorport);
+        if status == 221 % communication bus error
+            % recursive!
+            acc_vector = GetAccelerator(f_sensorport);
+            return
+        end%if
+        %idlecount = idlecount + 1;
     end%if
     
-    acc_vector = -1;
+    %fprintf('idlecount = %d \n', idlecount)
+%     if (status ~= 0) || (BytesReady < 6)
+%         disp('whoa')
+%     end%if
+    
+    acc_vector = [NaN NaN NaN];
 
 %% If ready get object distance (ultrasonic sensor value)    
@@ -38 +59 @@
         [data BytesRead] = NXT_LSRead(f_sensorport);
         
+        % IMPORTANT, DON'T FORGET!!!
+        % or change in NXT_LSRead
+        data = double(data);
+        
         if BytesRead > 5
-            if (data(1) > 127) data(1) = data(1) - 256; end
+            % as seen in the hitechnic example code...
+            % this is just a byte shift and could be done better, but
+            % should work
+            if (data(1) > 127) 
+                data(1) = data(1) - 256; 
+            end
             if (data(2) > 127) data(2) = data(2) - 256; end
             if (data(3) > 127) data(3) = data(3) - 256; end
@@ -48 +78 @@
         
         %------------------------------------------------------------------
+    else
+        [tmp msg] = checkStatusByte(status);
+        fprintf('Invalid sensor reading, %d bytes received, status %d: %s\n', BytesReady, status, msg);
+        
     end%if