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1:36 AM
What's a good convention for naming hierarchical blocks in Altium?
Particularly, the blocks which are repeated (multiple identical channels, for example).
 
@NickAlexeev I go for the shortest suffix possible, A, B, C, ... or 1, 2, 3...
 
 
4 hours later…
JRE
5:38 AM
@adamaero Your table shows about 4.3W total for your sensors and the Arduino. 4.3W * 24 hours gives 104 watt hours for a single day's operation.
 
 
3 hours later…
8:31 AM
@adamaero With the duty cycle you have, looks right. By the way, 1 Watt-second is 1 Joule
 
 
5 hours later…
2:01 PM
@glen_geek
Hi
Hi @glen_geek
 
 
2 hours later…
4:14 PM
It should only take a couple seconds for the Arduino to wake up. Then, sending the data via satellite (Rock BLOCK), I just guessed everything would take 5 minutes. This occurs four times a day. The rest of the time it's in sleep mode.
2-5 watt hours per day
^ rough calculation.
 
JRE
@adamaero Sounds much more reasonable for a sleeping system than 250Wh.
 
=)
 
JRE
Did you follow the link?
 
(6113 J)/(60min*60sec) = 1.7 watt hours
Yes, I read it. Very intuitive. Thx.
 
JRE
@adamaero Weird, that. I just put it up the day before you asked about energy calculations.
 
4:27 PM
Wow
 
JRE
I had that can of play-doh sitting on my workbench for a week, waiting for a chance to write that up.
 
 
1 hour later…
5:33 PM
@JRE The play-doh reminds me of how they taught us polynomial factorization in 5th grade.
 
JRE
6:14 PM
@ThePhoton Now that I'd like to see. I can relate play-doh to numerical integration, and from there to mathematical integration, but I'm not seeing a connection to polynomials.
 
If I have a 14 Ah battery, and a solar panel getting 4 hours of good sun.
That's 14 Ah/4 = 3.5 A.
Then 12V*3.5A = 42 W.
So a 50 W solar panel should work, but...
I'm confused on how the ~2 watt-hours factors in.
 
JRE
14Ah at 12V is about 168 Wh of energy. If you are using 2Wh per day, then your fully charged battery (from 4 hours of full sunlight) will power your Arduino-maboby for like 80 days.
 
But an AGM battery needs to be kept at 90% capacity...
So it's 16.8 Wh.
Agh, still don't get how to relate these quantities.
16.8+2 = 18.8 Wh
So with 4 hours of good sun, only a 5 W panel is needed?
 
7:02 PM
@JRE It wasn't play doh, it was bricks of size 1x1 and 1xX. But when you started cutting slices off the play-doh it had a similar effect.
 
7:24 PM
@everyone Does that seem right?
 
JRE
7:36 PM
@adamaero Eh. No. Wait a minute.
If you use a 5W solar panel, and have 4 hours of light, then you will capture some 20Wh of energy each day. That is 10 times what your Arduino-maboby is using. That gives you extra capacity - if the sun doesn't shine, you have a few days before the charge in the battery drops below 10 percent.
All of this ignores losses, of course. This is all the theoretical best case.
But, yeah a 5W panel could well do the job.
Figure 70% efficiency for the switching converter that goes from solar panel voltage to the battery charge voltage. Figure 50% efficiency for the battery, and again 70% for the conversion from battery voltage to the 7V for the Arduino. Maybe 30% efficiency overall.
If the sun don't shine, you have maybe three or four days before the battery gets too far down.
 
Thanks JRE. What's an Arduino-maboby?
 
JRE
An "Arduino-maboby" is a thingamabob made out of an Arduino.
 

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