Jaydeep Shah / Mbed OS 20_UART_FLUSH

UART SERIAL BUFFER CLEAR / FLUSH(). There is no direct function to clear UART buffer in Mbed, Trick require to handle this situation. Simple way is mentioned in this program to clear Rx buffer of UART. Jaydeep shah - radhey04ec@gmail.com

Files at this revision

API Documentation at this revision

Revision 0:3355c5b6d8fd, committed 2020-07-24

Comitter:
radhey04ec
Date:
Fri Jul 24 10:37:58 2020 +0000
Commit message:
UART FLUSH - FINAL COMMIT; PROGRAM TESTED AND COMPILED SUCCESSFULLY; ; JAYDEEP SHAH - radhey04ec@gmail.com

Changed in this revision

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CONTRIBUTING.md Show annotated file Show diff for this revision Revisions of this file
README.md Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.gitignore	Fri Jul 24 10:37:58 2020 +0000
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+.build
+.mbed
+projectfiles
+*.py*

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CONTRIBUTING.md	Fri Jul 24 10:37:58 2020 +0000
@@ -0,0 +1,5 @@
+# Contributing to Mbed OS
+
+Mbed OS is an open-source, device software platform for the Internet of Things. Contributions are an important part of the platform, and our goal is to make it as simple as possible to become a contributor.
+
+To encourage productive collaboration, as well as robust, consistent and maintainable code, we have a set of guidelines for [contributing to Mbed OS](https://os.mbed.com/docs/mbed-os/latest/contributing/index.html).

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/README.md	Fri Jul 24 10:37:58 2020 +0000
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+![](./resources/official_armmbed_example_badge.png)
+# Blinky Mbed OS example
+
+The example project is part of the [Arm Mbed OS Official Examples](https://os.mbed.com/code/) and is the [getting started example for Mbed OS](https://os.mbed.com/docs/mbed-os/v5.14/quick-start/index.html). It contains an application that repeatedly blinks an LED on supported [Mbed boards](https://os.mbed.com/platforms/).
+
+You can build the project with all supported [Mbed OS build tools](https://os.mbed.com/docs/mbed-os/latest/tools/index.html). However, this example project specifically refers to the command-line interface tool [Arm Mbed CLI](https://github.com/ARMmbed/mbed-cli#installing-mbed-cli).
+(Note: To see a rendered example you can import into the Arm Online Compiler, please see our [import quick start](https://os.mbed.com/docs/mbed-os/latest/quick-start/online-with-the-online-compiler.html#importing-the-code).)
+
+1. [Install Mbed CLI](https://os.mbed.com/docs/mbed-os/latest/quick-start/offline-with-mbed-cli.html).
+
+1. Clone this repository on your system, and change the current directory to where the project was cloned:
+
+    ```bash
+    $ git clone git@github.com:armmbed/mbed-os-example-blinky && cd mbed-os-example-blinky
+    ```
+
+    Alternatively, you can download the example project with Arm Mbed CLI using the `import` subcommand:
+
+    ```bash
+    $ mbed import mbed-os-example-blinky && cd mbed-os-example-blinky
+    ```
+
+
+## Application functionality
+
+The `main()` function is the single thread in the application. It toggles the state of a digital output connected to an LED on the board.
+
+## Building and running
+
+1. Connect a USB cable between the USB port on the board and the host computer.
+2. <a name="build_cmd"></a> Run the following command to build the example project and program the microcontroller flash memory:
+    ```bash
+    $ mbed compile -m <TARGET> -t <TOOLCHAIN> --flash
+    ```
+The binary is located at `./BUILD/<TARGET>/<TOOLCHAIN>/mbed-os-example-blinky.bin`.
+
+Alternatively, you can manually copy the binary to the board, which you mount on the host computer over USB.
+
+Depending on the target, you can build the example project with the `GCC_ARM`, `ARM` or `IAR` toolchain. After installing Arm Mbed CLI, run the command below to determine which toolchain supports your target:
+
+```bash
+$ mbed compile -S
+```
+
+## Expected output
+The LED on your target turns on and off every 500 milliseconds.
+
+
+## Troubleshooting
+If you have problems, you can review the [documentation](https://os.mbed.com/docs/latest/tutorials/debugging.html) for suggestions on what could be wrong and how to fix it.
+
+## Related Links
+
+* [Mbed OS Stats API](https://os.mbed.com/docs/latest/apis/mbed-statistics.html).
+* [Mbed OS Configuration](https://os.mbed.com/docs/latest/reference/configuration.html).
+* [Mbed OS Serial Communication](https://os.mbed.com/docs/latest/tutorials/serial-communication.html).
+* [Mbed OS bare metal](https://os.mbed.com/docs/mbed-os/latest/reference/mbed-os-bare-metal.html).
+* [Mbed boards](https://os.mbed.com/platforms/).
+
+### License and contributions
+
+The software is provided under Apache-2.0 license. Contributions to this project are accepted under the same license. Please see contributing.md for more info.
+
+This project contains code from other projects. The original license text is included in those source files. They must comply with our license guide.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Jul 24 10:37:58 2020 +0000
@@ -0,0 +1,128 @@
+//UART FLUSH()
+
+// This program is further improvement of circular buffer concepts
+/* Note : In Serial class library /or RawSerial class library there is no flush() command.
+Sometimes buffer clearing process require when you want to compare receiving data with pre-stored value
+or when doing some string related operation, because if you not clear UART buffer you will get old stored data.
+*/
+
+/*Note : simple way to clear Buffer : Read it , & reset all UART process related counter.*/
+
+//PROGRAM SUBJECT : UART BUFFER CLEAR / FLUSH()
+//Date : 24 July 2020 Version 1.0
+//JAYDEEP SHAH -- radhey04ec@gmail.com
+
+// I am sending one by one characters to slave and slave provide response according it , Ex : 'T' = Test Mode
+
+#include "mbed.h"
+#define BUFFER_SIZE 90   //SIZE OF BUFFER   ---DEPENDS ON YOUR DATA SIZE  --This is circular buffer
+
+char rxBuffer[BUFFER_SIZE];  //CREATE CIRCULAR BUFFER  -- TO STORE RECEIVE DATA
+
+unsigned int bufferReadingIndex=0;  //CREATE POINTER TO READ DATA FROM UART AND STORE INTO ARRAY
+
+unsigned int i=0; //counter to read data from buffer Array
+
+// 0 - Rx - PA_0   : Board Tx ___ Arduino Connector socket >>> First_pin _Orange  -- If FTDI CABLE USE
+// 1 - Tx - PA_1   : Board Rx ____ Arduino connector socket  >>> Second_pin _red  -- If FTDI CABLE USE
+
+//If you use only Serial calss , there is chance of damage OS because of MUTEX GUARD
+
+//use RawSerial class
+RawSerial UT(PA_0,PA_1);  //UART PIN DECLARATION
+RawSerial pc(USBTX,USBRX);  //HOST PC TERMINAL  - 9600 BAUD WITH 8-N-1 STTING
+
+//NOTE : UT OBJ FOR SLAVE BOARD & pc OBJ FOR TERMINAL
+
+//DEFINE Rx Interrupt function --DECLARATION
+void RxInterrupt(void);
+
+//Function that read response data
+void response(void);
+
+//FLUSH() UART
+
+void FLUSH(void); //Function declaration only
+
+int main()
+{
+UT.baud(57600);  //BAUD RATE SETTING
+UT.format(8,Serial::None,1);   //FORMAT OF UART COMMUNICATION
+
+//INTERRUPT ATTACHMENT WHEN RECEIVE DATA
+UT.attach(&RxInterrupt,Serial::RxIrq);
+
+pc.printf("\n TESTING TURN ON : \n");
+wait(1);
+
+UT.putc('T');  //ENTER IN TEST MODE  -- SLAVE BOARD ENTER INTO TEST MODE
+wait(0.5);
+response();  //Read Response from Slave 
+FLUSH(); // BEFORE SENDING /RECEIVING NEW DATA
+
+ThisThread::sleep_for(1000);
+
+UT.putc('d');   // RED LED OF SLAVE BOARD ON
+wait(1);
+response(); //Read Response from Slave
+FLUSH(); // BEFORE SENDING /RECEIVING NEW DATA
+ThisThread::sleep_for(5000);
+
+
+UT.putc('b');  // RED LED OF SLAVE BOARD OFF
+wait(1);
+response();  //Read Response from slave
+FLUSH(); // BEFORE SENDING /RECEIVING NEW DATA
+ThisThread::sleep_for(1000);
+
+UT.putc('Q');  //QUIT FROM TEST MODE -- NORMAL MODE SELECT
+wait(1);
+response();//Read response from Slave
+FLUSH(); // BEFORE SENDING /RECEIVING NEW DATA
+ThisThread::sleep_for(3000);
+
+while(1)
+{
+}
+
+}
+
+
+void RxInterrupt()      //if Rx buffer have data --- Interrupt call
+{
+    if(UT.readable())  //IF data available
+    {
+        rxBuffer[bufferReadingIndex++] = UT.getc();   // read and store into Buffer
+        if(bufferReadingIndex >= BUFFER_SIZE)  // If limit cross
+        {
+            bufferReadingIndex =0; // RESET CONTER
+        }
+    }
+}
+
+void response()  //FUNCTION TO READ DATA
+{
+    char rxByte;
+
+    while(i != bufferReadingIndex)  //READ WHILE COMPLETE DATA NOT RECEIVED
+    {
+        rxByte = rxBuffer[i];  //READ DATA ONE BY ONE CHARACTER
+        pc.putc(rxByte); // SEND ON TERMINAL
+        i++;  //COUNTER INCREMENT
+        
+        if(i >= BUFFER_SIZE) //IF LIMIT CROSS
+        {
+            i = 0;   //RESET COUNTER
+        }
+    }
+}
+
+void FLUSH()            //FLUSH FUNCTIONS
+{
+    RxInterrupt(); // This is because read data if something available in UART buffer
+    
+    //Counters which are related with UART reading process make it zero again
+    i = 0U;
+    bufferReadingIndex = 0U;   
+    
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Fri Jul 24 10:37:58 2020 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#cf4f12a123c05fcae83fc56d76442015cb8a39e9

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