New solar project: Minimal system

Hello all,

my next post about a minimalistic ATmega system is online. Several interesting methods for reducing power consumption are shown. This happens both in run mode and in sleep mode. Measurements of supply current are included to see what really happens. This gives an in-depth view to power-reduction.

If interested, have a look at:

http://heliosoph.mit-links.info/arduino-powered-by-capacitor-reducing-consumption/

heliosoph

Hello all,

I did some tests with what I found out about the supply current in different modes. As I have only little computing time and a lot of sleep time most of the energy is consumed during sleep.  If interested look at:

http://heliosoph.mit-links.info/arduino-powered-by-capacitor-optimized-tests/

Enjoy

heliosoph

Hello all,

I added a code example that shows what I did for reducing power whilst asleep.  If interested look at:

http://heliosoph.mit-links.info/arduino-powered-by-capacitor-optimized-tests/

Enjoy

heliosoph

A great series, I look forward to reading these in more detail.

I was going to suggest looking at the "Shrimping.it" project but it seems you are way ahead of that already.

Thank you, Andy for your comment! Now here are some new details:

My project is going further now (was stuck a while). Waking up from sleep mode is now done with DS1337 RTC (similar to the well-known DS1307 but has a wider supply voltage range). Now a new problem occured and this is what the latest post is all about: Using external interrupt for wakeup from sleep mode.

In SLEEP_MODE_PWR_DOWN only level interrupts are possible. Interrupt triggering on the falling or rising edge of the signal doesn't work. Now multiple interrupts can be generated when the signal lasts too long.

The post in my blog shows how to prevent this. Included is a test sketch and also some screenshots from my scope that show the beaviour.

If interested, look at:

http://heliosoph.mit-links.info/atmega328p-wakeup-sleep-via-interrupt/

hope this helps

Elektrix

Hello all,

I finished the post about using a RTC instead of the wathdog timer for better timing accuracy and lower supply current. Now that the problems with the interrupt signal are already solved it shows that although supply current is reduced total uptime of the system didn't rise. So probably the main losses are somewhere else. So further research has to be done...

If interested, look at:

http://heliosoph.mit-links.info/arduino-powered-by-capacitor-timing-with-rtc

Hope this helps

heliosoph

Hello all,

now I've added an example sketch that has interrupt handling included. The datalogging part is the same as in earlier examples and the interrupt part comes from the basics post. Here it's all together.

If interested, look at:

http://heliosoph.mit-links.info/arduino-powered-by-capacitor-timing-with-rtc/

heliosoph

The "Arduino powered by a capacitor" system is now extended again: I've added an external EEPROM. It is a 24AA256 that has the same wide supply voltage range as the ATmega328. Communication is done via I2C. Clearly, we have more memory space now. But what has shown up is that energy consumption has become lower because the external EEPROM is faster and consumes less power than the internal one. In the post there are some pictures from my scope that show the differences.

If interested, look at:

http://heliosoph.mit-links.info/arduino-powered-by-capacitor-extending-memory/

heliosoph

Hello all,

with my new external EEPROM I have tested writing in page mode. This is really a cool thing  Up to 64 bytes are written (almost) in the same time as a single byte. This extends the total uptime of my capacitor powered arduino (precisely: standalone ATmega328P) with a factor of more  than nine. Total uptime is now in the range of two and a half hours!!

If interested, look at:

http://heliosoph.mit-links.info/arduino-powered-by-capacitor-eeprom-page-mode/

heliosoph

Hello all,

now I've gone one step further with my project. Now it's going towards real life. I began with changing the logging interval. This shows the influence of both the consumption while running and sleeping. The next step is to take a supercap as energy source. The first part of the post is already online. If interested, look at:

http://heliosoph.mit-links.info/arduino-powered-by-capacitor-towards-real-system/

heliosoph