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Topic: A Digital Beehive: A scientific study proposal. (Read 6 times) previous topic - next topic

GoForSmoke

You could put the ID into the AVR program as data and have a function to "print it out".

I believe that Afremont has practical experience with DS18B20's. He certainly does with 1-wire.

If it was me, I'd have the sensors in each frame with a molex connector to one AVR per box. 


I find it harder to express logic in English than in Code.
Sometimes an example says more than many times as many words.

kasslloyd

#16
Apr 15, 2013, 03:17 am Last Edit: Apr 15, 2013, 03:30 am by kasslloyd Reason: 1
Probably have to be something smaller than molex, the frames dimensions are not exactly huge. There would be enough area on the top to carve out and put a circuit board in and then epoxy it in to seal it off from water and secure it... A frame top is 1 1/8" wide and 17 5/8" long. The circuit would need to be pretty skinny to fit embed into the top. Attached is some dimensions of hive boxes and frames. For the brood chambers we'd be using the large size (9 1/8" deep frames).

(here's a source to help understand a hive construction: http://www.beesource.com/resources/usda/types-of-hives-and-hive-equipment/ )

Oops, I thought an AVR per frame... per box is more reasonable. Any good way to give a frame, regardless of which box/position it's plugged in a unique ID that is readable along with all the sensors on that frame?

kasslloyd

#17
Apr 15, 2013, 03:41 am Last Edit: Apr 15, 2013, 03:45 am by kasslloyd Reason: 1
It seems 1-wire devices include a unique ID with them, if that's the case if theres 8 1-wire temp sensors per frame, then if you can pull that unique ID then a unique ID could be generated for the whole board by using those 8 ID's of the chips? Is this feasible?

If that's not doable then maybe this chip: DS2401 it's specificly designed for 1-wire to provide a unique ID, http://pdfserv.maximintegrated.com/en/ds/DS2401.pdf

GoForSmoke

Quote
It seems 1-wire devices include a unique ID with them, if that's the case if theres 8 1-wire temp sensors per frame, then if you can pull that unique ID then a unique ID could be generated for the whole board by using those 8 ID's of the chips? Is this feasible?


Entirely. I'd go with the ID of the 1st device since it's unique and likely 8 bytes or more.

Have you PM'd Afremont?

Here's a USB business card that uses a surface mount ATtiny85, just so you have an idea of size.

http://www.frank-zhao.com/cache/usbbusinesscard.php

The Tiny85 is 8 pins of what the 328P is 28 pins. The surface mount versions are all thin.

The DS18B20 is a bit bigger than a match head. They can be made right into a thin cable.

You could take through-hole AVR's, bend the legs out to the sides and connect the ones you need with female jumpers or female crimp connectors on wires. Solder if you dare, use heat-shrink if you don't. You don't _need_ a board. You only need power, ground, a bypass cap, and whatever pins connect to your sensors. You don't need 16 MHz external crystal either, you can run on the internal 8 MHz oscillator and divide that down to use less power. Epoxy that, it won't be 1/2" thick.
I find it harder to express logic in English than in Code.
Sometimes an example says more than many times as many words.

kasslloyd

Yea I sent a PM.

If its just an AVR per box, then it's size is irrelevent, since it can be outside of the hive, just put a connector on the outside of the box that goes in to connect to each of the frames. Then the AVR for the box can be safely mounted outside. If it's per frame, then that will need some tiny chips, which would be an issue I think. :-\

There will need to be a way for the AVR to tell each frame apart, without any mixups, even if the order of frames change.

I would then assume the AVR's for the boxes would then connect to an Arduino that will read via a serial line the temp data out? Or, we could just actually burn the Arduino patform onto individual AVR's per box, then connect all those back up to the central computer and write a simple program that reads out the temp data every 10 minutes and saves it as a CSV, that would be the ideal?

We could run several Cat5 cables from the hive back into the house, then put individual serial lines on those wires, then connect it all up via USB-to-Serial connectors inside, then a small program to read out those datas and write to a CSV... nothing complex here, just needs to be stable ;-\


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