Hi team,
One of our customer needs some suggestions based on LPCMP Windowed mode.
Use case is, consider two input signals(12V power lines) are connected to the microcontroller pins in LPCMP0(in0 & in1 channels).
Need to monitor the voltage levels of both input signals to check the normal operating voltage(12V-15V).
Can Windowed mode(out of window) voltage detection be used to monitor the normal operating(12V - 15V)
Please Note: Lower and higher references need to be configured using DAC output internally for each input.
Unable to find any reference code related to this.
To summarize:
1) Is it is possible to do Windowed mode(out of window) voltage detection in S32K3 LPCMP?
2) If so how we can configure for Lower and higher references for the input pins?
3) What configuration will be ideal for windowed mode operation ? Could not able to see option for upper limit & lower limit value in .mex file?
Waiting for the response!
Thanks & regards,
Krishnakumar V
Thank you for your interest in our products and for contributing to our community.
For LPCMP there is just available the LpCmp_Icu_Ip_BlinkLed_S32K388 RTD example. Which is configured in continuous mode.
The LPCMP needs 2 signals to compare (INP and INM), for your application you need to compare an external input with the internal DAC (which its voltage is configurable).
As you want to compare 2 external signals, each one with respect the internal DAC. It is recommended to use 2 LPCMP instances. Please consult Table 1. S32K3xx chip's feature comparison of datasheet to see how many instances are available in the S32K3 derivative you are using.
If you have just one instance available, please consider that there is no any RTD function to change the inputmux during run time. So most probably you need to de-init, change inputmux and re-init the LPCMP instance.
On the other hand, there are no upper/lower limits, the threshold is defined by the DAC voltage level.
Please also consider that for windowed mode, you need to route the WINDOW/SAMPLE signal thought TRGMUX.
I hope this information is helpful.
