Main Site Documentation

Regarding Low power mode in EMX


#1

I am working on one project with EMX. My requirement is to send the unit in low power mode if one will not touch the screen for 10 second. It should weak-up when EMX receives interrupt from Rs232 port.

I have refer the document Beginners guide to NETMF.pdf, section 29 Low Power (page no 148). Form the reference I feel that Shutdown the processor when system is idle (keep peripherals and interrupts running) will work as per my requirement. But I didnt get any examples related to shutdown the processor. The given examples are for Hibernate only.

Can someone please guide, as per my requirement the way of Shutdown processor is perfect or not? If yes please provide the example and in case of other way also please provide the example.

Can some one please suggest that how to convert Decimal to Hex in Dot net MF?


#2

You will need to use hibernate feature then add some simple circuitry so you can wakeup the processor using one of the IOs…for example connect the wakeup pin to UART receive.

Notre that the first byte received will be lost due to the system being in hibernate.


#3

I have checked the hibernate with FEZ(interupt IO23) and it is working properly. But I want that during my low power mode, the application should be active in background like my threads, timers and Rs232 communication should work. I have checked with my current hibernate settings but timer thread is not working.

Please guide me if any other way or hibernate settings are require to achieve my requirement.

I also want to weak-up the FEZ on either of two interrupt like on IO23 pin interrupt or Rs232 interrupt. In below statement only one parameter is allowd

Power.Hibernate(Power.WakeUpInterrupt.EINT0);

How would i set for two interupts?


#4

Hibernate = the system is completely off, no timers, nothing works. Even the system time will probably be off when you wakeup from hibernate. Yo need to read thee RTC and update system time.


#5

Then what if i need to set sleep mode for low power consumption? where my processes are going on but LCD display is off.


#6

If you just want to turn the LCD off, you can use a transistor like a 2N2222 to control the power pin on the LCD. You then use one of the free pins to control the transistor like a switch.


#7

“Sleep” is automatically done when the system is idle. Now, you can further reduce power by shutting down some parts of your system, like the LCD