seeker
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Post by seeker on Nov 16, 2020 17:08:38 GMT -6
Has anyone built any temp cables and have they lasted over the years. I saw on the other site 4-5 years ago the posts are and wondering if its worth my time to build some. Even if it cost 30 dollars a cable, beats 400 for a bin sense. I dont know if I can post the link from the other site but it is called Grain Monitoring System, post 71 is detailed in how one made it. Also has anyone done the wifi and be able to look at the reading in the house
Thanks
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warreng
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Post by warreng on Nov 16, 2020 19:47:22 GMT -6
i did temp ones, no wifi though, direct plug in reader .. used thermistors ..
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Post by Beerwiser on Nov 16, 2020 21:13:10 GMT -6
I am monitoring my coal stoker over wifi. Been running steady for a good 4 years. Using a ds1820 and a esp8266.
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Post by torriem on Nov 17, 2020 17:13:54 GMT -6
I thought about it briefly but decided it just wasn't worth it to try to thread a steel cable along with some wires, sensors, through some plastic tubing. Moisture cables are much more difficult, but there's certainly nothing too special about the sensors and how they are wired and programmed in 2-wire temperature-only cables.
I have some older temperature cables that are 15 years old. I don't think a homemade cable would last that long. Grain is pretty abrasive and puts a lot of weight on those cables as they load and unload. I'm actually surprised the roof tin doesn't buckle a bit where they hang.
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seeker
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Post by seeker on Nov 17, 2020 17:57:14 GMT -6
That is one of my concerns is that the diy cables wont last. My brother who went to school for circuit board and programming and is willing to try to build some. I will see what he can come up with over the winter. We have the old op1 cables and reader and they are alright. If I can find some of those for a bargain that would be a way to go also.
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Post by torriem on Nov 17, 2020 18:09:29 GMT -6
Well you've got very little to lose if he's willing to put in the time. It would be a fun project. I elected not to do it because I didn't have the time to devote to it. To get the opi to see them, you have to write the sensor number to the templow of each sensor chip. If you had 6 sensors in the string, they just get numbered sequentially, 1,2,3,4,5,6. To be compatible with the OPI reader, you should wire the sensors in parasitic power mode (see the data sheet). If you are in western Canada, Solarbotics in Calgary carries the DS18B20 sensors and ships quite quickly. |
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Post by Beerwiser on Nov 19, 2020 23:04:15 GMT -6
I agree about solarbotics, another one is robotshop. Both good to deal with if you want it now. Anyhow I had a good conversation with both seeker and his brother. Turns out they farm not to far from me. Anyways just brainstorming a way to protect the sensors in the bin. Any thoughts on running them down a pvc electrical conduit, then poking them out the side of the particular location. Then secure them to to the outside of the pvc with hose clamps, possibly sealing the exit hole with silicone or even tape. This would be for the stainless housed ds18b20.
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Post by torriem on Nov 19, 2020 23:10:21 GMT -6
The person who made their own cables on the other forum had a steel cable that he wrapped the wires and sensors around, and then stuffed the whole thing in some plastic tubing. I assume flexible tubing. Maybe if the sensors were epoxied to the steel cable such that the epoxy would protect the sensor (about the size of a transistor) when the grain pushed against it.
I like your conduit idea though. I don't think you'd need any sticking of the sensor through the pipe. It should conduct the heat well enough to the air inside. In fact I'd be tempted to use galvanized metal conduit. That would take the load no problem and conduct the heat very well.
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Post by Beerwiser on Nov 20, 2020 0:07:28 GMT -6
I was thinking of galvanized conduit too, but a slightly different way. Not sure how it would work, but instead of having multiple sensors at different heights have one sensor maybe 3' from the top the conduit. If there is a hot spot anywhere on the metal conduit the heat should rise and hit the sensor. This way instead of say having six sensors in a single vertical line a guy could run six lengths of pipe at a teepee style configuration and get better coverage of the bin.
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warreng
Full Member
Posts: 119 Likes: 8
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Post by warreng on Nov 20, 2020 7:37:29 GMT -6
i used a steel cable [1/8 inch] for the strain relief, and added sensors every two feet starting at two feet ... the sensors and wire were covered by heat shrink tubing, and a three pound weight at the bottom ..
these were for smaller bins, say upto 18 feet inside , larger bins get spaced every three feet, all cables had eight sensors
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Post by northernfarmer on Nov 20, 2020 8:41:55 GMT -6
warreng, was that short sections of typical heat shrink for each sensor location as otherwise I can only imagine what a bin height length of that would end up costing. Now as to the rest of the system where it hangs from inside the bin roof and sealing the wires that come through, wiring outside of the bin down the wall and the connector to lets say connect onto the older style OPI reader system, what are you using. You mentioned 8 sensors so that is 8 wires and is there some fine wire cord that has a high count of wires. That is years ago I had installed a couple of cables and never had gotten around to installing more and then they changed the system so what I have is obsolete but what they made was a nice sealed up unit that wasn't bad to install into the roof with that pin that slid through the rubber head/internally molded cable end and the weather protected connection on the side of the bin and trying to get my head wrapped around the idea of mimicking that.
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Post by Beerwiser on Jan 4, 2021 21:25:02 GMT -6
Not sure how far you made it with what I gave you, but I have a working code for you. Based on a nodeMCU and uploading all the live data to thingspeak so I can monitor everything on my phone. Ended up having to build a quick repeater too with another nodeMCU since that building is all metal inside and out. All together less then 30 bucks. Code is attached if anyone else wants to play with it. Attachment DeletedAttachment Deleted |
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