hscmp_polling#
Overview#
The HSCMP polling Example shows the simplest way to use HSCMP driver and help user with a quick start.
In this example, user should indicate an input channel to capture a voltage signal (can be controlled by user) as the HSCMP’s positive channel input. On the negative side, the internal 6-bit DAC is used to generate the fixed voltage about half value of reference voltage.
When running the project, change the input voltage of user-defined channel, then the comparator’s output would change between logic one and zero when the user’s voltage crosses the internal DAC’s value. The endless loop in main() function would detect the logic value of comparator’s output, and change the LED. The LED would be turned on when the compare output is logic one, or turned off when zero.
Supported Boards#
LPCXpresso55S36
Hardware requirements
Micro USB cable
Personal Computer
LPCXpresso55S36 board
Board settings
This example project uses HSCMP to compare the voltage signal input from channel 3(P1_5) with the voltage signal(half of VREF_OUT) output by HSCMP’s internal DAC and output different result. LED_RED will turn ON/OFF corresponding to different result. So the voltage signal input from P1_28 should be changed to observe the dynamical LED state.
Input signal to J9-9
Prepare the Demo
Connect the micro and mini USB cable between the PC host and the USB ports(J1) on the board.
Open a serial terminal on PC for the serial device with these settings:
115200 baud rate
8 data bits
No parity
One stop bit
No flow control
Download the program to the target board.
Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.
Running the demo
The following lines are printed to the serial terminal when the demo program is executed.
HSCMP polling Example.