Hardware requirements
Micro USB cable
MIMX8ULP-EVK/EVK9 board
J-Link Debug Probe
5V power supply
Personal Computer
Board settings
This example project uses ACMP instance 1 to compare the voltage signal input from External Input2(J12-5) with the voltage signal(half of 1.8V) output by ACMP’s internal DAC. Terminal will print information corresponding to different comparison result.
Please note that the input voltage should in the range of 0 to 1.8V.
Connect ACMP Input2(J12-5) to DC power supply.
Please remove the R291 which connect to J12-5(or the PIN J12-5 is not able to input voltage)
Please note this application can’t support running with Linux BSP!
Prepare the Demo
Connect 5V power supply and J-Link Debug Probe to the board, switch SW1 to power on the board.
Connect a micro USB cable between the host PC and the J6 USB port on the target board.
Open a serial terminal with the following 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 example.
Running the demo
If the input voltage input is in the range of 0.9V to 1.8V, that means the analog input is higher than DAC output. If the input voltage input is in the range of 0V to 0.8V, that means the analog input is lower than DAC output.
When the demo runs successfully, following information can be seen on the terminal:
The example compares analog input to the reference DAC output(CMP positive port).
The terminal will print CMP's output value when press any key.
Please press any key to get CMP's output value.
The analog input is LOWER than DAC output
The analog input is HIGHER than DAC output