Jason Tay / Mbed 2 deprecated mbed_quadBlinky

This is a souped up version of the basic mbed blinky, as a 2nd stepping stone up from the basic blinky and also because the documentation doesn't seem to really be that complete.

Dependencies:   mbed

Fork of mbed_quadBlinky by Jason Tay

main.cpp@1:f4e48249b980, 2017-10-03 (annotated)

Committer:
shutay
Date:
Tue Oct 03 17:00:33 2017 +0000
Revision:
1:f4e48249b980
Parent:
0:efe13d6feef8 
Added more comments for beginners.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
shutay 0:efe13d6feef8 1 #include "mbed.h"
shutay 0:efe13d6feef8 2
shutay 1:f4e48249b980 3 // You can write out debug strings via the mbed interface and the built-in mini-USB socket.
shutay 0:efe13d6feef8 4 Serial pc(USBTX, USBRX);
shutay 0:efe13d6feef8 5
shutay 1:f4e48249b980 6 // All 4 built-in LEDs defined.
shutay 0:efe13d6feef8 7 DigitalOut led1(LED1);
shutay 0:efe13d6feef8 8 DigitalOut led2(LED2);
shutay 0:efe13d6feef8 9 DigitalOut led3(LED3);
shutay 0:efe13d6feef8 10 DigitalOut led4(LED4);
shutay 0:efe13d6feef8 11
shutay 1:f4e48249b980 12 // Example initialisation function
shutay 0:efe13d6feef8 13 void initialise()
shutay 0:efe13d6feef8 14 {
shutay 0:efe13d6feef8 15 // Baud rate not required over USB.
shutay 0:efe13d6feef8 16 led1 = 1;
shutay 0:efe13d6feef8 17 led2 = 1;
shutay 0:efe13d6feef8 18 led3 = 1;
shutay 0:efe13d6feef8 19 led4 = 1;
shutay 0:efe13d6feef8 20 wait(1.0f);
shutay 0:efe13d6feef8 21 //*==========================================*
shutay 0:efe13d6feef8 22 // Do initialisation here
shutay 0:efe13d6feef8 23 //*==========================================*
shutay 0:efe13d6feef8 24
shutay 0:efe13d6feef8 25 //*==========================================*
shutay 0:efe13d6feef8 26 led1 = 0;
shutay 0:efe13d6feef8 27 led2 = 0;
shutay 0:efe13d6feef8 28 led3 = 0;
shutay 0:efe13d6feef8 29 led4 = 0;
shutay 0:efe13d6feef8 30 wait(1.0f);
shutay 0:efe13d6feef8 31 }
shutay 0:efe13d6feef8 32
shutay 1:f4e48249b980 33 // The LED blinking code was split out into 2 functions with different parameter
shutay 1:f4e48249b980 34 // passing methods to incrementally add more sophistication and complexity into
shutay 1:f4e48249b980 35 // the basic mbed_blinky example. Those familiar with C/C++ won't need this sort
shutay 1:f4e48249b980 36 // of help, but if mbed is your first foray into C/C++, this will help...
shutay 1:f4e48249b980 37
shutay 1:f4e48249b980 38 // Take the parameter passed to us in variable 'val' and use the value in it
shutay 1:f4e48249b980 39 // to update the LEDs. We essentially use the value in 'val' as a bit field
shutay 1:f4e48249b980 40 // telling us which LEDs to light up, in a way that corresponds directly to the
shutay 1:f4e48249b980 41 // bit position.
shutay 0:efe13d6feef8 42 void updateLEDs(int val)
shutay 0:efe13d6feef8 43 {
shutay 0:efe13d6feef8 44 led1 = val & 0x01;
shutay 0:efe13d6feef8 45 led2 = (val & 0x02) >> 1;
shutay 0:efe13d6feef8 46 led3 = (val & 0x04) >> 2;
shutay 0:efe13d6feef8 47 led4 = (val & 0x08) >> 3;
shutay 0:efe13d6feef8 48 }
shutay 0:efe13d6feef8 49
shutay 1:f4e48249b980 50 // A simple bitwise shifting function to create an LED chaser effect.
shutay 1:f4e48249b980 51 // This function is different as it takes a pointer to the original variable.
shutay 1:f4e48249b980 52 // i.e., it is expecting the address to an int variable, not simply the value
shutay 1:f4e48249b980 53 // itself.
shutay 0:efe13d6feef8 54 void advanceLEDs(int *val)
shutay 0:efe13d6feef8 55 {
shutay 0:efe13d6feef8 56 *val = *val << 1;
shutay 0:efe13d6feef8 57 if(*val>0x08) *val = 1;
shutay 0:efe13d6feef8 58 }
shutay 0:efe13d6feef8 59
shutay 0:efe13d6feef8 60 int main()
shutay 0:efe13d6feef8 61 {
shutay 0:efe13d6feef8 62 initialise();
shutay 0:efe13d6feef8 63
shutay 0:efe13d6feef8 64 int i = 1;
shutay 0:efe13d6feef8 65 while(1)
shutay 0:efe13d6feef8 66 {
shutay 0:efe13d6feef8 67 updateLEDs(i);
shutay 0:efe13d6feef8 68 advanceLEDs(&i);
shutay 0:efe13d6feef8 69 wait(0.5f);
shutay 0:efe13d6feef8 70 }
shutay 0:efe13d6feef8 71 }