Comments on: Moisture Meter for Plants http://www.imsolidstate.com/archives/506 Always improving things... Tue, 10 Aug 2010 17:13:41 -0600 http://wordpress.org/?v=2.8.4 hourly 1 By: imsolidstate http://www.imsolidstate.com/archives/506/comment-page-1#comment-1971 imsolidstate Tue, 22 Jun 2010 14:11:58 +0000 http://www.imsolidstate.com/?p=506#comment-1971 The step-up converter is TI's TPS61221. It's incredibly small at 2mm x 2mm, SC-70 6-pin package. I made the PCB on my CNC, but it was really at my machine's limits. It worked well, and seems pretty efficient at the load I was using (the AVR). You may want to select a different part depending on your load to get better efficiency. The curves for efficiency vs. current draw are given in the datasheet. They have a few different parts to match high efficiency with current draw. I used the reference design from TI's datasheet to make the schematic. There's even a recommended layout. http://focus.ti.com/lit/ds/symlink/tps61221.pdf The step-up converter is TI’s TPS61221. It’s incredibly small at 2mm x 2mm, SC-70 6-pin package. I made the PCB on my CNC, but it was really at my machine’s limits.
It worked well, and seems pretty efficient at the load I was using (the AVR). You may want to select a different part depending on your load to get better efficiency. The curves for efficiency vs. current draw are given in the datasheet. They have a few different parts to match high efficiency with current draw.
I used the reference design from TI’s datasheet to make the schematic. There’s even a recommended layout. http://focus.ti.com/lit/ds/symlink/tps61221.pdf

]]> By: Muris http://www.imsolidstate.com/archives/506/comment-page-1#comment-1963 Muris Tue, 22 Jun 2010 07:04:32 +0000 http://www.imsolidstate.com/?p=506#comment-1963 Hi, I can't see what step-up regulator you are using in this project. Can you share the schematics with us? I am working on an "automatic blinds" and don't have much room for the batteries there, so this booster IC would be just perfect for me! Regards! Hi,

I can’t see what step-up regulator you are using in this project. Can you share the schematics with us? I am working on an “automatic blinds” and don’t have much room for the batteries there, so this booster IC would be just perfect for me!

Regards!

]]> By: Olliho http://www.imsolidstate.com/archives/506/comment-page-1#comment-1821 Olliho Mon, 14 Jun 2010 03:29:25 +0000 http://www.imsolidstate.com/?p=506#comment-1821 Hi there, can you, please, supply the schematic diagram for this very interesting project? thanks Hi there, can you, please, supply the schematic diagram for this very interesting project?
thanks

]]> By: imsolidstate http://www.imsolidstate.com/archives/506/comment-page-1#comment-556 imsolidstate Thu, 04 Mar 2010 14:28:33 +0000 http://www.imsolidstate.com/?p=506#comment-556 Hey, I like that. That would work really well. I didn't think of putting a button on it to "check soil", but using that approach you could omit the batteries completely. I may have to start playing with the new supercapacitors, as you suggested it would be perfect for this application. The probes were just some small copper tubing that I tinned and then put heat shrink on. Hey, I like that. That would work really well. I didn’t think of putting a button on it to “check soil”, but using that approach you could omit the batteries completely. I may have to start playing with the new supercapacitors, as you suggested it would be perfect for this application.
The probes were just some small copper tubing that I tinned and then put heat shrink on.

]]> By: Rui Martins http://www.imsolidstate.com/archives/506/comment-page-1#comment-555 Rui Martins Thu, 04 Mar 2010 04:18:44 +0000 http://www.imsolidstate.com/?p=506#comment-555 A possible better approach, would be to use a solar powered Cell, together with some kind of battery/accumulator (Capacitor ?) and then have a push button to trigger the test ! This way, no AAA batteries are required, and it still is simple to use. Are you using ferrite rods, to stick into the soil ? A possible better approach, would be to use a solar powered Cell, together with some kind of battery/accumulator (Capacitor ?) and then have a push button to trigger the test !

This way, no AAA batteries are required, and it still is simple to use.

Are you using ferrite rods, to stick into the soil ?

]]> By: Life2Death http://www.imsolidstate.com/archives/506/comment-page-1#comment-251 Life2Death Fri, 01 Jan 2010 01:08:42 +0000 http://www.imsolidstate.com/?p=506#comment-251 How about you publish PCB files and schematics? How about you publish PCB files and schematics?

]]> By: imsolidstate http://www.imsolidstate.com/archives/506/comment-page-1#comment-81 imsolidstate Sun, 08 Nov 2009 01:34:13 +0000 http://www.imsolidstate.com/?p=506#comment-81 I just used the fact that the soil will have some varying amount of conductivity based on the level of moisture in the system. Dry soil won't conduct electricity, but wet soil will because of the high levels of impurities dissolved in the water by the soil. The circuit I made just checks the amount of conductivity of the soil at some interval, and then flashes an appropriate color LED. I just used the fact that the soil will have some varying amount of conductivity based on the level of moisture in the system. Dry soil won’t conduct electricity, but wet soil will because of the high levels of impurities dissolved in the water by the soil. The circuit I made just checks the amount of conductivity of the soil at some interval, and then flashes an appropriate color LED.

]]> By: Jason http://www.imsolidstate.com/archives/506/comment-page-1#comment-80 Jason Sat, 07 Nov 2009 23:07:01 +0000 http://www.imsolidstate.com/?p=506#comment-80 This seems like an interesting concept, do you have an explanation on the method used to measure the moisture content? What about the circuit/programs you developed? This seems like an interesting concept, do you have an explanation on the method used to measure the moisture content? What about the circuit/programs you developed?

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