View Full Version : Newbie Introduction
09-10-2006, 10:15 PM
I would like to introduce myself and possibly give you some idea of who I am and what I would like to accomplish.· First off, I am a retired Navy chief petty officer and make my home in Raiatea, French Polynesia.
I have been working in digital electronics since the 60's, but have never tried to do a project as large as this with the responsibilities this entails...
I am interested in building a system that will monitor 4 to 5 chill rooms, 3 walk in freezers and 4 display cases.· I want them to record the temperatures every hour, and also to alarm if any of the temperatures rise to 40 degrees Fahrenheit in the case of the chill rooms and 0 degrees Fahrenheit in the case of the freezers.· I would also like to run the outputs directly to a dot matrix printer for a record, and have the capabilities to have the system to dial out to the persons responsible if the system does alarm and inform them which unit has failed.· I realize that I am probably biting off more than I can chew, but if I can get ideas from those of you in here who have been building and using the various parallax products.· I may just be able to make this happen.·
This is for my nephew's business which is a total meat processing facility that he has purchased, and is trying to update and modernize.· He is processing Asian Water Buffalo, Domestic Elk, Cattle, Sheep, Goats, and Pigs.· The chill rooms have, on the average 30 to 45 cattle carcasses, 3 to 4 buffalo, and 40 to 50 pigs· and several head of sheep and goats...· As you can see, it would be catastrophic if any of the coolers went down or if we lost a freezer for any length of time.· The plant does not have a night person as of yet, and if we were to lose a cooler it wouldn't be noticed for hours,·or on the weekends, days.
What I would like to know, is this feasible, and will Parallax work for what I am trying to do?· Also I am sure that I will need help writing the software, and any ideas on backups for a fail safe system...
Any and all help/ideas are gratefully accepted....
CPO USN Ret.
Post Edited (maheanuu) : 9/10/2006 2:28:18 PM GMT
As for measuring the temperature I would recommend this IC http://www.parallax.com/detail.asp?product_id=604-00002
For the printer, use a TTL serial printer (like those receipt printers).
You don't say how far apart the rooms are. You may have to make something fancy if they are too far apart.
Cheap used 4-digit LED display with driver IC·www.hc4led.com (http://www.hc4led.com)
Low power SD Data Logger www.sddatalogger.com (http://www.sddatalogger.com)
SX-Video Display Modules www.sxvm.com (http://www.sxvm.com)
There are only two guaranteed ways to become weathy.
Spend less than you make.
Make more than you spend.
09-11-2006, 12:13 AM
Bean, thanks for the quick reply... The rooms are about 100 feet from the office and the phone lines/computers... The reason for the printout without computer is that all of the users including the USDA inspector do not have computers available to read a record. but I will be networking the computers and having the data logged and filed on a master record...
I am only in the planning/ordering stage at present, and will be starting the programming stage as soon as I order and receive the first unit... Lotsa wurk <grin>, but it will keep me outta trouble......
09-11-2006, 04:46 AM
There are several good resources that you can look at on the Parallax site. You can download all of their courses in PDF format, and in your situation, you might consider looking at the following:
1. What's a Microcontroller - basic intro to Basic Stamp systems
2. Applied Sensors - deals with environmental data collection and logging
3. Industrial Control - Deals with process control with the Basic Stamp
4. Process Control - An updated version of Industrial Control
For sensors, you might want to look at iButtons by Dallas Semiconductor. They are i-Wire protocol devices, and can be accessed directly via 1 pin on the BS2p24, BS2p40, BS2pe, and BS2px. You can use them with other Stamp modules, but you'll need additional circuitry.
For logging the data, you might want to consider StampPlot Pro, which is used in the Process Control text. As for redundancy - just build 2!
09-11-2006, 07:54 AM
This thread is being moved from the Forum Support section to the Sandbox Forum.
Parallax Tech Support
09-11-2006, 04:08 PM
Go for the iButtons, or more specifically the DS1921 'ThermoChron' iButtons, as not only can they measure temperature, but also log(intervals from 1 to 255 minutes between measurements) and store the results in local memory(no data lost if the BS2 must be rebooted), and they can set an 'Alarm state' if temperatures rise over a specified point.
Don't visit my new website...
09-12-2006, 11:01 AM
I would also recommend the thermometer that Bean posted (2nd post). It works great and it's cheap.
The best failsafe would probably be to run multiple sensors in each room, or to run two separate systems altogether (dialing on two separate lines, or by different methods). After setting up the first system, the second system should be a lot simpler, and the only cost would be the materials, which shouldn't be that expensive.
Some of the issues that may be of concern:
1) distance between rooms, will the signal travel that far without amplification? Will it be wirelessly transmitted?
2) getting a microcontroller (whichever one you use) to dial out: through a computer? phone? text message? you should see if anyone has done this before and if its easy or not
Issues that seem hard but are actually simple:
1) programming a microcontroller to read the sensor (very simple)
2) wiring the sensor-pretty easy but again, not sure about long distances
Parallax products should be able to do this, and above all else, their tech support is good.
I am interested in building a system that will monitor 4 to 5 chill rooms, 3 walk in freezers and 4 display cases.· I want them to record the temperatures every hour, and also to alarm if any of the temperatures rise to 40 degrees Fahrenheit in the case of the chill rooms and 0 degrees Fahrenheit in the case of the freezers.· I would also like to run the outputs directly to a dot matrix printer for a record, and have the capabilities to have the system to dial out to the persons responsible if the system does alarm and inform them which unit has failed.··...
CPO USN Ret.
Ken, It seems you'd want to learn about refrigeration failure at the earliest possible time. Monitoring the room temperature of the cooler / freezer itself --if they're well insulated-- may provide warnings _much_ later than the component equipment failure occurred.
Once you get the basic microcontroller / sensor / reporting system design process down, you will probably find that you can easily extend your control system to sense/report on other (upstream) refrigeration system components too, with the coldroom temperature sensing being just the last-gasp warning of a problem.
And, as someone else suggested, you'll probably find that building redundant systems will probably be a drop in the bucket of added cost compared to the potential cost of inventory loss.
09-12-2006, 01:39 PM
Par, your advise is very well thought out and excellent...· I didn't mention this before, but I was a refrigeration tech along with doing power generation, electrical contracting and inspections for the isles sous le vent (leeward islands of the Societies in French Polynesia for over 20 years...· I am planning on using pressure sensors on the suction side (evaporators) and probably will use air vane switches on the fans which will let me know if any of them fail...· I only made mention of the temps as they are the bottom line for the USDA...· I would never want the rooms to reach those temp's especially if I have 30 or 40 thousand pounds of product in the room...
Your thoughts are exactly like mine, and I should have expressed myself better...· I really didn't introduce myself to all of you very well, so I will give you a little idea of where I am coming from and a little background on my training and expertise...
I am a retired Navy Chief Electronics Technician, and loved my job and my rate...· I started on tin cans, and went to heavy cruisers, then I was on an APA and had a communications station where I got involved in crypto.· All along the way I volunteered for every school that came up as I loved electronics and loved the challenge and the ability to fix anything that seemed to come my way...· I finally ended up in the Mobile Technicial Units which, at the time, was the highest echelon of repair the Navy had...·· I worked on every type of electronics equipments the Navy had, and became well qualified in digital systems...· I retired out in '74 and became a field engineer for Sperry-Univac working on computer systems and networking...· I was assigned back to the Navy as a Field Engineer· which the Navy called a CETA (Civilian Electronics Technician Afloat).· There were only 24 of us who worked on all electronics equipment and systems·on the ships we were assigned to,·and I feel honored to have been one of them.· I was assigned as ships company to the USS·Berkely, USS·Lynde McCormick, and the USS Tarawa during my time as CETA.
I immigrated to Tahiti in the late 70's and having worked on no break power systems including the prime movers, and having repaired and maintained the chilled water systems for the heavy radars, I had the experience in power generation and refrigeration already down, and started my own business there doing the heavy work that I had done before...· Computers were almost non existant in Tahiti, the only ones there when I first arrived were those involved in the French Atomic tests, and as I was an immigrant, and not being French (at that time), there was no chance for me to work in the field that I had recently vacated.· I brought with me to Tahiti a Sinclair Z80· and learned Sinclair Basic and machine language so that I could write programs to run on my "doorstops"...· I bought and used every Sinclair model that was produced and loved those great machines...· I became involved with the PC after having been given a Compac Lug Along that had DOS installed and used a 5 1/4 floppy drive...· This unit was not operable when I received it and after writing for the manuals I managed to repair it and the rest is history...· I know for sure that I brought the first personal computer into Tahiti as everyone laughed at the sinclair and the fact that I was building a data base / spread sheet to keep records with, while everyone else was doing everything by hand...·
I am married to a wonderful Tahitian lady, and we have two children, my daughter is a nurse at our island hospital, and my son is a tile layer working for a construction company that builds hotels...· I have 2 grandsons one that is now 14 and the other is only 17 months...
I still love computers, electronics, photography, big game fishing, and fishing in general....· I find everything and everyone interesting, and love learning something new and challenging...· If any of you might like to know more about me, feel free to visit my photo site at http://mah.smugmug.com you will probably understand more about me from my photos, than my blather...
I am very glad to have joined this site, and am planning on taking some goodies home with me when I return this December..· I may be able to get my grandson and his cousin interested in microprocessors and control units and provid them with something that they might like to learn for even a better chance at the future..
Nuff said, and hope that I didn't bore you all to tears....· I could say a hell of a lot more, but I will save some of the suprises for a little further down the line...· I love life, and have lived it more fully than anyone else in my family, I am not afraid to try anything and feel that there is no shame if I might fail to accomplish something the first time.· I would be ashamed to not have tried at all....
Just this old chief's 2˘
09-12-2006, 04:57 PM
If you are interested in failsafe, the iButtons do have alarms and CRC to verify correct operations. The Thermochron is also a data logger and really is a bit expensive for an end of a network thermometer. There are other Maxim One-wire sensors that are 1/10th the cost.
But if you need remote control in those sites [e.g. shut down lights or deadbolt entries], CANbus would allow you to specify a location and a device for control. Distances of 1000 feet can easily be set up on 2 wires. It too has CRC and sends data in 8 byte packets. Transmissions can either be one-shot or repeated if the first is a failure due to network collisions. One-wire sensors can easily be integrated into it via BasicStamps or SX-28s or Propellers as node translators. You can have tens of nodes.
In other words, there are lots of choices. Mostly it is about making the learning fun, not steep.
Try the DS1921 first. I just got one and it is awesome and very handy. Later you can use it as a node or as a diagnotic tool to confirm that your system is reporting correctly. It is a good introduction to One-wire.
"If you want more fiber, eat the package.· Not enough?· Eat the manual."········
···················· Tropical regards,····· G. Herzog [·黃鶴 ]·in Taiwan