| .. _blink-led-sample: |
| |
| PWM: Blink LED |
| ############## |
| |
| Overview |
| ******** |
| |
| This is a sample app which blinks a LED using PWM. |
| |
| The LED will start at a blinking frequency of 1 Hz. Every 4 seconds, |
| the blinking frequency will double. When the blinking frequency |
| reaches 64 Hz, the blinking frequency will be halved every 4 seconds |
| until the blinking frequency reaches 1 Hz. This completes a whole |
| blinking cycle. This faster-then-slower LED blinking cycle repeats forever. |
| |
| Wiring |
| ****** |
| |
| Arduino 101 and Quark D2000 CRB |
| =============================== |
| You will need to connect the LED to ground and PWM0 via the shield. |
| You may need a current limiting resistor. See your LED datasheet. |
| |
| Nucleo_F401RE and Nucleo_L476RG |
| =============================== |
| Connect PWM2(PA0) to LED |
| |
| Nucleo_F103RB |
| ============= |
| Connect PWM1(PA8) to LED |
| |
| Hexiwear K64 |
| ============ |
| No special board setup is necessary because there is an on-board RGB LED |
| connected to the K64 PWM. |
| |
| Building and Running |
| ******************** |
| |
| This sample can be built for multiple boards, in this example we will build it |
| for the arduino_101 board: |
| |
| .. code-block:: console |
| |
| $ cd samples/basic/blink_led |
| $ make BOARD=arduino_101 |
| $ make BOARD=arduino_101 flash |
| |
| After flashing the image to the board, the user LED on the board should start to |
| blinking as discussed in overview |
| |
