|
|
| (13 intermediate revisions by 4 users not shown) |
| Line 1: |
Line 1: |
| − | <sidebar>Sidebar: What Is a Component?</sidebar>
| + | For an excellent introduction guide, we recommend [https://www.flowcode.co.uk/education/ Introduction to microcontroller programming] |
| − | 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|30px]] 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|30px]] 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|30px]] 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|30px]]
| |
| − | ::* 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|30px]] 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|30px]].
| |
| − | :* 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 the 'Single LED' in the 'Outputs' toolbox in the [[Tools and Views#1) Icons Toolbar|Icons toolbar]].
| |
| − | :* Hover over the image to the left of the 'Single LED' label, 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 shows that, by default, it is connected to Port A, bit 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|30px]].
| |
| − | * 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|30px]] when you are happy with the program's behavior.
| |
