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<sidebar>Sidebar: What Is a Component?</sidebar> The aim of this exercise is to demonstrate the use of analogue input devices within a Flowcode flowchart. Digital inputs are simpler to deal with, as they have a finite range of possible values.<br /> For example, a two bit digital input can have one of only four possible values - 00, 01, 10 or 11.<br /> Flowcode uses an 'Input' icon [[File:Btn Input.gif|border]] to deal with digital inputs. An analogue input, on the other hand can have any of an infinite number of possible values.<br /> As a result, it is more difficult to handle in Flowcode. [[File:Exercise_Using_Analogue_Input_Devices_System_Panel.png|300px|right]] A component macro [[File:Btn Component Macro.gif|border]] is used to input data from an analogue sensor.<br /> The data is then stored in a variable. Component macros are sections of code that have been written to support the components included with Flowcode 6.<br /> They take all the effort out of using these components. In this exercise, a warning lamp lights when the signal from an ADC dial device rises too far. __TOC__ ==The flowchart sequence== The flowchart will: ::::* Read the value set on the input device, the ADC dial. ::::* Compare this with a set value, and: ::::: if greater than the set value, turn on a lamp; ::::: if less, then make sure that the lamp is off. ::::* Loop back to the beginning, and repeat the process. [[File:Exercise_Using_Analogue_Input_Devices_Variable_Manager.png|300px|right]] ==Create the 'input' variable== :* In the 'Edit' menu, on the main toolbar, click on 'Variables...' to open the [[Variable Manager]] dialogue box. ::* Hover just to the left of the 'Variables' label, and click on the down arrow that appears. ::* Select 'Add new' and the 'Create a New Variable' dialogue box opens. ::* Name the new variable "input". ::* Leave the variable type as 'Byte'. ::* Click on 'OK'. ::* The dialogue box is shown opposite. ==Create the flowchart== * Click and drag an infinite loop, [[File:Btn Loop.gif|border]] between the 'BEGIN' and 'END' icons. [[File:Exercise_Using_Analogue_Input_Devices_Component_Macro_Properties.png|300px|right]] * Inside the loop: :* Click and drag a 'Component macro' icon.[[File:Btn_Component_Macro.gif|border]] ::* Double click on it to open the dialogue box, so that you can configure it. ::: The program 'knows' which components you have added to the System or Dashboard panel, and modifies the list of available commands accordingly. ::: Under 'Components', the ADC dial will be listed, and underneath it the list of commands. ::* Scroll down the list and click on the 'GetByte' command. ::: This reads the output of the analogue input device - the ADC dial in this case, and stores it in the byte variable called 'input'. ::* Rename the 'Display name' as "Read the input". ::* Click on 'OK'. ::* Again, the dialogue box is shown opposite. * Next, drag and drop a 'Decision' box, [[File:Btn Decision.gif|border]] and double click on it to open the dialogue box. [[File:Exercise_Using_Analogue_Input_Devices_Decision_Properties.png|300px|right]] :* Rename it "Compare it !" :* In the condition 'If' box, type "input>128". :: The '128' is totally arbitrary in this program. A byte variable can store any value from 0 to 255, so 128 is roughly half way. :: In this case, the program decides whether the value stored in the variable 'input' is greater or smaller than 128, and reacts differently depending on that decision. :* Click on 'OK'. ::* Again, the resulting dialogue box is shown opposite. [[File:Exercise_Using_Analogue_Input_Devices_Output_Properties_01.png|300px|right]] * In the 'Yes' branch, drag and drop an 'Output' icon, [[File:Btn Output.gif|border]]. :* Double click on it to open the dialogue box. :* Change the 'Display name:' to "Switch on the lamp". :* In the 'Variable or value:' box, type "1". :* Configure the rest of the box to output this to 'PORT A' 'Single Bit:' 0. :* Click on 'OK'. [[File:Exercise_Using_Analogue_Input_Devices_Output_Properties_02.png|300px|right]] * In the 'No' branch, drag and drop a second 'Output' icon. :* Double click on it to open the dialogue box. :* Change the 'Display name:' to "Switch off the lamp". :* In the 'Variable or value:' box, type "0". :* Configure the rest of the box to output this to 'PORT A' 'Single Bit:' 0. :* Click on 'OK'. ::* Again, the dialogue boxes for the 'Output' icons are shown opposite. The flowchart should now resemble the one shown below. [[File:Exercise_Using_Analogue_Input_Devices_Flowchart.png|300px|center]] ==Add the LED== * Locate an [[Component: ID a7b05886 784c 48c8 a6f6 cc371c7728e1|LED]] such as the [[Component: ID 7fdaec78 394e 4ec9 a578 4f1a12a12076|LED 5mm Panel]] in the 'Outputs' toolbox in the [[Tools and Views#1) Icons Toolbar|Icons toolbar]]. :* Hover over the image to the left of the component label 'LED 5mm Panel', and click on the down-arrow that appears. :* Click on the 'Add to system panel' option to select it. :* Select the LED on the System panel and drag it to a suitable position. :* Look at the Panel Properties, the 'Connection' property make sure that it is connected to Port A, bit 0 ($PORTA.0). :: Leave it like this. ==Add the ADC dial== The ADC dial represents a number of input devices. * Locate the 'ADC dial' in the 'Inputs' toolbox in the [[Tools and Views#1) Icons Toolbar|Icons toolbar]]. :* Hover over the image to the left of the label, and click on the down-arrow that appears. :* Click on the 'Add to system panel' option to select it. :* Select the ADC dial on the System panel and drag it to a suitable position. :* Look at the Panel Properties, and locate the 'Connection' property. Just below it, the 'Channel' property shows that, by default, it is connected to 'AN0' - the first bit of the microcontroller capable of accepting an analogue input. Click on 'AN0' to open a pinout of the microcontroller. ::* Click on the rectangle representing input 'AN1' to change the connection to this channel. :: Leave it like this. The System Panel should resemble the image shown at the top of the page. ==Final testing== * Save the flowchart as 'Analogue,fcf'. * Click on the simulation button [[File:Btn Run.png|border]]. * Use the mouse to turn the pointer on the ADC dial, and notice what happens when you pass the half-way mark. * Click on the 'Stop simulation' button, [[File:Btn Stop.png|border]] when you are happy with the program's behavior. ==Download the exercise== You can download the file created by this exercise and open it in Flowcode to identify errors in your program/file or you could also download the file to skip to the next exercise. *To download the file, click on the link below and then either: :*Click on the file name. :*Right click the file name and select 'Save link as...' or 'Save target as...' (depending on your browser). :::[[File:Exercise - Using Analogue Input Devices.fcfx]]

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