S32K312 - About Low power and ADC input

[ssean]

Hello.

My project has 6 wakeup source.

4 Digital(GPIO) and 2 Analog (ADC).

4 Digital port pin used WKPU and it works fine.

1. How can I read ADC during standby mode?

Is LPCMP module can read analog value during standby ?

2.

But my analog port pin not connected to CMP_xx.

It connected PTB8 and PTE16.

Is there any solution for my project ?

3. 

How can I make low power task?

A. Set WKPU and RTC

B. Enter standby

C. Wakeup from RTC

D. Check ADC and Re-Enter standby

In this sequence, should I set again WKPU and RTC between C and D ?

4.

After wakeup, should I init and set again clock and peripherals for read adc ?

Is there simple solution for read adc in after wakeup ?

Thank you.

[danielmartynek · Accepted solution]

Hello @ssean,

1-2.

The ADC module is not active in the Standby mode, unlike LPCMP.

LPCMP in the round robin can be used, but the wakeup signals would need to be connected to the LPCMP pins.

3-4.

Becasue the standby wakeup goes through a functional reset, the peripherals must be initialize again.

Here you can find some examples:

https://community.nxp.com/t5/S32K-Knowledge-Base/S32K3-Low-Power-Management-AN-and-demos/ta-p/152772...

Regards,

Daniel

[ssean]

@danielmartynek 

I try bellow setting and it works fine.

Could you double check my configuration?

1. Negative Muxing: CMP0_IN3

2. Positive Muxing : DAC (Voltage about 4.75)

1) When I release input switch, CMP0_IN3 is 5V.

CMP0_IN3 > DAC == INM > INP == (COUT_RAW is LOW)

2) When I push input switch, CMP0_IN3 is 1.5~4.5 V.

CMP0_IN3 < DAC == INM < INP == (COUT_RAW is HIGH)

3) Wakeup at rising edge of COUT_RAW.

Am I understood correct?

Thank you.

[danielmartynek]

Hello @ssean,

I'm sorry for the delay.

I haven't seen the whole project, but this should work.

BR, Daniel

[ssean]

@danielmartynek 

Thank you for reply.

Your mentions very helpful for me.

BRs, Sean