// solved my issue, thread can be closed //
First of all, what is the use of the microcontroller on the Arduino board going to sleep, when everything else requires so much current ?
The components on the Arduino board require current and the Ethernet Shield requires a big amount of current. The few milli-amperes that you preserve with sleep mode are negligible.
When you build a bare-bones Arduino, the ATmega chip can go into sleep mode with the Watch Dog timer. There is a library for that : Google Code Archive - Long-term storage for Google Code Project Hosting.
When returning from sleep mode, an SPI device might have to be reinitialized again. I'm not sure about that, I have never looked into it. The ATmega chip does almost a full reset after waking up with the WDT.
You could measure the current when running normal and when the ATmega is in sleep mode. I think that you almost won't see the difference.
Peter_n:
First of all, what is the use of the microcontroller on the Arduino board going to sleep, when everything else requires so much current ?
The components on the Arduino board require current and the Ethernet Shield requires a big amount of current. The few milli-amperes that you preserve with sleep mode are negligible.When you build a bare-bones Arduino, the ATmega chip can go into sleep mode with the Watch Dog timer. There is a library for that : Google Code Archive - Long-term storage for Google Code Project Hosting.
When returning from sleep mode, an SPI device might have to be reinitialized again. I'm not sure about that, I have never looked into it. The ATmega chip does almost a full reset after waking up with the WDT.You could measure the current when running normal and when the ATmega is in sleep mode. I think that you almost won't see the difference.
Hello!
This is a school project and it is suppose to be a rat trap detection system whereby we make use of the flex sensor to detect whether the mouse trap door has been closed or not. Currently we are using the Ethernet Shield for the project as our supervisor could not get a Wifi shield or a Xbee shield. His objective for me is to be able to put the Arduino to sleep and send a reading to Xively when the flex sensor is being flexed.
Initally I tried using the Digital Pin 2 as an interrupt pin but I soon realised it was not possible as the sensor takes an AnalogReading. Hence, with the suggestion of someone, I took up the idea of using a WDT to take a reading and upload the reading to Xively.
I see that you disable the ADC before going to sleep, but it doesn't look like you re-enable it before doing the reading.
electricteardown:
I see that you disable the ADC before going to sleep, but it doesn't look like you re-enable it before doing the reading.
Hmm indeed. Where do you suggest I re-enable the ADC? After "sleep_disable();"?