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REMOTE WIRELESS DATA LOGGER
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REMOTE WIRELESS DATA LOGGER

by vivelaterre on Mon Feb 04, 2019 2:13 am

I want to record and display a year's worth of sunlight readings from my barn roof to assess the feasibility of installing a solar electric array there. I need advice on coding and choice of equipment (Feather Huzzah?). I will have to learn Arduino IDE and how to chart the data on my pc or my iMac with High Sierra and Windows. I want to log, at 15-minute intervals, the year, month, day, hour, and minute, the 0 to 114mV output of an Apogee SP-510 thermopile pyranometer, a voltage indicating the sensor 's position, the battery state, and maybe temperature. The relative inaccessibility of the roof calls for wireless data transmission. My cellphone and Kindle show one bar of signal strength at the barn from our home WiFi network router. The pyranometer has a 12VDC 18.5mW 25.4 mA defrosting heater. I could run a power cord to the roof, but it would be nice if I could power everything with my 70 sq. in. solar panel (Goal Zero Nomad7, 7W, 5V usb up to 1.4A) and its usb battery (5200mAh, 1.5A in, 2.1A out). Many thanks in advance to anyone who reads my ramblings.

vivelaterre
 
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Re: REMOTE WIRELESS DATA LOGGER

by adafruit_support_mike on Mon Feb 04, 2019 3:09 am

That project will have a lot of moving pieces and design options.

One major design consideration is that the microcontroller that collects and transmits the data doesn't have to be all that close to the sensor cluster. Weatherproofing electronics is a serious challenge, and it's almost always preferable to keep as much hardware indoors as possible. Sensors that use digital signals are useful in those circumstances, because it's fairly easy to run digital signals up to 100' through standard CAT-5 phone cable. In most cases you can use one pair of wires in the cable to carry power, and use the other pairs for signals.

That gives you more flexibility on power, and better accessibility for the microcontroller itself. You could still use the solar panel for most of the power, but since you're doing a solar feasibility study, it's prudent to assume you'll lose the light long enough to cause problems at some point in the year. Having a backup power source or two will make the system more resilient.

That still leaves valid reasons to use a wireless connection to transmit the data, and the most useful option for that application would probably be a packet radio board:

https://www.adafruit.com/?q=packet%20radio

Those use a simple connection protocol, and are good for distances up to a few hundred meters.

Redundancy in your data collection is a good idea too, so adding the option for the microcontroller to write data to an SD card would probably be a good idea. The Adalogger FeatherWing is a good choice for that:

https://www.adafruit.com/product/2922

and it includes a real-time clock, which will be helpful for taking readings every 15 minutes.

Receiving data on a computer, logging it, and processing it will be fairly straightformward with Processing:

http://processing.org/

It's a software package specifically designed for managing communcation between computers and programmable hardware, and is compatible with boards that use the Arduino programming IDE (Integrated Development Environment.. a combination of text editor, compiler, and software to upload firmware to a microcontroller).

If you're new to hardware programming in general, a Feather 32u4 would probably be a decent place to start. The microcontroller has enough processing power to handle the jobs necessary for a data logging project, and is simple enough that you won't have to deal with too many technical details.

Our 'Learn Arduino' series of tutorials starts from scratch, and introduces you to the general techniques of microcontroller programming:

https://learn.adafruit.com/adafruit-ard ... on-1-blink

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Re: REMOTE WIRELESS DATA LOGGER

by vivelaterre on Wed Feb 13, 2019 1:03 am

Mike, thank you for your thoughtful reply. I like the idea of using a cable instead of a wireless connection. The pyranometer includes a 5-meter 2-pair cable, one pair for heater power and one for analog data. That means I can put the electronics securely inside the barn and plug into the wall for power. I am thinking of using a Feather 32u4 Basic Proto with the RTC+SD add-on. This way I can access the SD card for data at anytime when the sun is not shining on the sensor.

vivelaterre
 
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Re: REMOTE WIRELESS DATA LOGGER

by adafruit_support_mike on Fri Feb 15, 2019 4:15 am

That should work, yes.

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Please be positive and constructive with your questions and comments.