mbed_example / Mbed OS BusIn_HelloWorld

BusIn HelloWorld

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Use

BusIn is an abstraction that takes any pins and makes them appear as though they are linearly memory mapped for ease of use. This abstraction is useful for checking multiple inputs in a single pass. In general this abstraction can be used to make code less cluttered, clearer, and take less time to write.

Note

Please pay attention to the ordering of pins in the initialization. The order pins are initialized in are the reverse order that bits are OR'd together.

API

API reference.

Import librarymbed

No documentation found.

main.cpp

Committer:
sarahmarshy
Date:
2017-06-26
Revision:
8:1e81bff34109
Parent:
6:e1f4151bb580

File content as of revision 8:1e81bff34109:

/* mbed Example Program
 * Copyright (c) 2006-2014 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "mbed.h"

BusIn nibble(D0, D1, D2, D3); // Change these pins to buttons on your board.

int main() {
    
    // Optional: set mode as PullUp/PullDown/PullNone/OpenDrain
    nibble.mode(PullNone); 
    
    while(1) {
        // check bits set in nibble
        switch(nibble & nibble.mask()) { // read the bus and mask out bits not being used
            case 0x0: printf("0b0000, D3,D2,D1,D0 are low  \n\r");break;
            case 0x1: printf("0b0001,          D0  is high \n\r");break;
            case 0x2: printf("0b0010,       D1     is high \n\r");break; 
            case 0x3: printf("0b0011,       D1,D0 are high \n\r");break;
            case 0x4: printf("0b0100,    D2        is high \n\r");break;
            case 0x5: printf("0b0101,    D2,  ,D0 are high \n\r");break;
            case 0x6: printf("0b0110,    D2,D1    are high \n\r");break;
            case 0x7: printf("0b0111,    D2,D1,D0 are high \n\r");break;
            case 0x8: printf("0b1000, D3           is high \n\r");break; 
            // ...
            case 0xF: printf("0b1111, D3,D2,D1,D0 are high \n\r");break;
        }
        wait(1);
    }
}