What happens to adc pins in sleep mode?

[martinnossel]

I noticed that the temperature sensors on the nodes had started reading 15 to 20 deg more than they should (used to).

I believe its the sleep mode which is now being used, and that the adc pin is being pulled high or low on sleep and causing the sensor to self heat. I am not doing it in software.

I am onsite so I cant check whats happening on the pins till tonight.

If you have the page of the datasheet with whats going on with the adc pins and sleep mode, it woiuld save me a bit of time.

Martin

[Jheath]

Pins configured to be digital outputs will hold their state when the system enters sleep mode.

Similarly, ADC pins (ie pins 11-18) set to be inputs will not be alterred (high or low) when entering sleep mode.

In fact, ADC pins (set to be inputs) are internally configured as digital inputs until the readADC() function is called. This procedure configures the ATD converter for the duration of the read, then returns to the previous configuration. ADC pins should behave like all other inputs.

Chapter 14 of MC9S08GB60A Data Sheet discusses the ATD process.

[martinnossel]

opps, I see I was changing the stae of the adc pins before sleeping.

[vijayaraj]

Hi all,
What happens to the configured adc in the sleep mode.Does the adc will run in the sleep mode(1,xxx) by consuming some amount of current?.I am using EK2500 kit with PAN4555 module on it.

[Jheath]

The processor is not able to process commands when the module enters either of the sleep modes.

It is available for processing after the reciever is disabled (by using the rx(False) function). However, it is obviously no longer able to tx/rx wireless information.

[Jheath]

The processor is not able to process commands when the module enters either of the sleep modes.

It is available for processing after the reciever is disabled (by using the rx(False) function). However, it is obviously no longer able to tx/rx wireless information.


Ooops. This should have been posted to the other thread....

[Jheath]

Does the adc will run in the sleep mode(1,xxx) by consuming some amount of current?.I am using EK2500 kit with PAN4555 module on it.

It is always recommended that un-used pins be set to outputs and pulled low (whether they are digital or ADC pins).

ADC pins configured as inputs are treated as digital inputs until the call to perform the actual read is made. As such, these pins will be digital inputs at the time the unit goes to sleep. The RFE should not be consuming any additional power. However, your connected peripherals must be conditioned properly (ie disabled or put to sleep themselves) before executing the sleep call.

[vijayaraj]

Can we use the ADC module when the chip has entered the doze mode ?

[kbanks]

No you cannot.

No attention is paid to any of the various peripherals while sleeping, the one exception being the KBI (Key board Interrupt) "wakeup" pins.

The "ignored" devices include the UARTS and the ADCs.

Your SNAP node should sleep for a period of time, wake up and check ADCs (etc.), act on what it sees, and then go back to sleep.