Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Planet Monitoring System Using Sensors

Status
Not open for further replies.

qmelis

New Member
Hello all,

I'm an EE student working on my senior project, but my group and I are still in the design stage. We're designing a planet monitoring system that measures moisture, sunlight, temperature, and pH, cataloging this information in a database, and providing an interface that allows users to easily use this info to improve their gardening techniques.

We have a few questions that we've developed to help us pare down our vision, and I'd be really grateful if any of you could answer some or all of them. Feel free just to address whichever question strikes your fancy. (Hopefully, there is a question that does.)

Thank you all very much.

Engineering Questions

How will we deal with the effects of temperature on the pH measurement?

What are some ways to provide waterproofing?

What are acceptable margins of error for our sensor measurements?

What government licenses or regulations should be consulted?

What interface would be best in providing the customer with data?

Will we provide simultaneous measurements or provide them one by one through a switching mechanism?
 
hi qm,
I assume that it will be soil aka dirt in which you are measuring the pH.? if so, you would need to measure the soil temperature.
If you are collecting all the data using a suitable interface to a PC it would be easy to use the PC for any calculations.

When say 'moisture' is that the moisture content of the soil?
Many outdoors sensors are already waterproofed.

Whats the data sampling rate as this will have some bearing on the overall accuracy of the system.?

I have used a password web page site for posting data to customers/clients.

For the simultaneous measurements, it depends upon the sampling rate.

Eric
 
Thanks, Eric, for the responses.

Yes, pH and temperature will both be measured from the soil.

The idea is to have an all-in-one unit to measure and display the information, so we were thinking of a simple LCD display though we're open to better suggestions.

In terms of waterproofing, the components (sensors and such) are less of a problem than the actual casing we'd use to house this system. The device has to be attractive in some sense and we weren't sure if there are options we should be aware of.

hi qm,
I assume that it will be soil aka dirt in which you are measuring the pH.? if so, you would need to measure the soil temperature.
If you are collecting all the data using a suitable interface to a PC it would be easy to use the PC for any calculations.

When say 'moisture' is that the moisture content of the soil?
Many outdoors sensors are already waterproofed.

Whats the data sampling rate as this will have some bearing on the overall accuracy of the system.?

I have used a password web page site for posting data to customers/clients.

For the simultaneous measurements, it depends upon the sampling rate.

Eric
 
Actually, measuring the pH of a solid is quite difficult and is virtually meaningless. In fact, you will be measuring the pH of water in the soil. The problem is that temperature correction works fine for water, somewhat for defined electrolyte solutions, and not very well for undefined solutions. Some salts show a positive and some show a negative pH change in solution with increased temperature. I thought that was why you listed it as a problem in your initial post.

My solution would be:

1. Create a calibration vs. temperature curve for the soil in which you have the electrode (i.e., create a table of observed pH at various temperatures vs. pH@20°C ); or
2. Just report the observed pH and the temperature at which it was measured.

The change may not be enough to worry about. You may need to add a defined amount of distilled water to the soil before observing the pH. You could also put a soil sample in a temperature-controlled environment before you measure its pH. But then, you would always be testing a new sample, which is probably not what you want to do.

John
 
hi,
There is an extensive range of high impact plastic IP65 and IP68 water proof cases available, see links for some options.
Water proof connectors are also readily available.

Sorry about length of the links!

Can you say how you plan to power the instrument package and sensors?

How much data do you intend to store before downloading to a PC, a USB interfaced PIC controller could be used.
E

https://uk.farnell.com/jsp/search/browse.jsp?N=2031 204381 110027237 110030807&Ntk=gensearch&Ntt=IP68 enclosures&Ntx=mode matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=2031 204381 110027237 110108991&mm=1000923||,1001150||,100000||,1001830||,1001921||,1002303||,1002334||,1002335||,1002672||,1002719||,1002738||,1002901||,1002902||,&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=/jsp/search/browse.jsp?N=2031+204381&Ntk=gensearch&Ntt=IP68+enclosures&Ntx=mode+matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=2031+204381

https://uk.farnell.com/jsp/search/browse.jsp?N=2031 204382 110027237&Ntk=gensearch&Ntt=IP65 enclosures&Ntx=mode matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=2031 204382&mm=1000923||,&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=/jsp/search/browse.jsp?N=2031+204382&Ntk=gensearch&Ntt=IP65+enclosures&Ntx=mode+matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=2031+204382

https://uk.farnell.com/jsp/search/browse.jsp?N=2031 204381 110030807&Ntk=gensearch&Ntt=IP65 cases&Ntx=mode matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=2031 204381&mm=1001150||,&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=/jsp/search/browse.jsp?N=2031+204381&Ntk=gensearch&Ntt=IP65+cases&Ntx=mode+matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=2031+204381

EDIT:
This is one of the types I have used, they are not cheap.
**broken link removed**
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top