Posts Tagged ‘vegetables’

Control two 120v electrical outlets with your computer

16.4 years ago computer power control, electronics, solid state relay


Here is one more component for "Project Everbearing" which requires the ability to toggle a 120V power source using my PC. Now there are a few interesting applications for this, home automation, music synced Christmas display, or just the nerd factor of being able to say I can turn on my coffee maker from your web enabled phone. Whatever your need, hopefully with these instructions you can do this yourself.

If we had lawyers, they probably would want us to say this:
WARNING: I am not an electrician and do not pretend to be one.  I do not know the specific building electrical codes of your area, so please be sure your wiring is completed under the proper safety code for your area. As always, using high voltage electricity can result in self-electrocution or burn down your house if not done safely so if you are not comfortable doing this wiring please contact a qualified professional.

Materials:

  • 2 – 20 amp solid state relays (got off eBay for $4.00 each)
  • 1 – Outlet box (Home Depot for $2.00)
  • 2 – 20 amp outlets (Home Depot for $1.25 each)
  • 1 – 2 outlet switch plate (Home Depot for $0.50 each)
  • 1 – PC power cable
  • 2 – LEDs (optional)

The outlet I am plugging this into is 15 amps, though my use for this project will be considerable under this but best to place for worst case scenario and I would rather trip a circuit breaker than who knows what happens when solid state relays or outlet exceeds their limits. I could have saved a couple dollars and gone with cheaper mechanical relays but solid state will last much longer even with frequent toggling on/off.

Now for the build, this was actually surprisingly easy and took less than an hour from start to finish. I first fed the power cable through and three stands of low voltage wire through access in back. I cut about 6 inches of wire off the end of the power cable. Using the continuity feature of my voltmeter I verified the hot, neutral, and ground, then checked one more time. I attached the neutral and ground in parallel to both outlets. I then connected the hot from the power cord to left side of both SSRs. I then used the 6 inches of wire I cut off to connect from left side of SSR on both and connected a wire from the left side to the corresponding outlet.

Now to add the ability to turn the things off/on using low voltage. I hooked up the wires fed through the back (which will later be hooked up to computer’s parallel port) green to positive SSR #1, red to SSR #2, and black to both grounds. Now with 3-12 volts of power to these connections will activate the SSR and provide power to the outlet. For a little added effect and easy confirmation everything is working (even with the unit unplugged) I also attached corresponding red/green LEDs that match the wires (I am getting old color coding helps) I was doing this hack indoors though first thought was to use my soldering iron to burn a nice little hole into the outlet plate but didn’t want to stink up the house, so risked using a drill instead. As you can see from the pictures I should have gone outside. With a little solder and hot glue everything seemed to be staying together.

With all the wiring completed, I carefully packed everything into the outlet box. The SSR were already pretty snug but I added little but of hot glue in case they feel like shifting around after everything was put back together. Being careful that wires are staying secure and no shorts are being created carefully screw the outlets to the outlet box. Finish it up with a (cracked) outlet plate and the assembly is complete.

Now the scariest part still remains, which is testing, first part is plugging this monster in. If you plug it into the wall and no sparks occur you are in pretty good shape but not in the clear yet. Plug something like a nightlight into your switchable outlet box, should be off now. Using a 9-volt battery connect black to (-) and red to (+) if you didn’t cross your wires anywhere the red LED should come on and appliance plugged in should get power. Now switching to the other side do the same with the green wire and appliance comes on with sparks or fires looks like a successful build.

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Create a cheap PC thermometer with PS2/Gamepad Controller

16.4 years ago cheap, electronics, PC thermometer

You might be thinking what does this post have to do with vegetable gardening? Bear with me, I don’t have time to do a complete write up on it right now but let’s just say this is a component for “Project Everbearing” I gave my 7-year-old the honors of coming up with the codename, since he is my faithful assistant and cheerleader.

For my current project I need the ability to measure temperature with my PC. Now there are plenty of gadgets out there I could have simply purchased a commercial product for around $40+ and saved myself a lot of time but I really wanted to brush some dust off my soldering iron and try to save some cash, this is the CHEAP vegetable gardener after all.

After a little searching online seemed like a good place to start was to pick up a few thermoresistors which is a special type of resistor which increases resistance as the temperature increases. With no luck at my local RadioShack I picked up a few on EBay for less than $1 a piece.

Now comes the hard part of actually using them, since the computer I was using was old enough it still have an old 15-pin game port I went that route first. This would have been my easiest method of implementation by simply connecting the resistor to pin 1 and pin 3, since analog joysticks work with variable resistance as well. They use what is called a potentiometer which as the user moved the stick to left/right it raises/lowers the resistance. If this would have worked all that I would have needed to do is get the measurement and start calibration. Unfortinately this port was no longer responsive so I have to go with another option

Fortunately I never throw anything electrical out and pulled an old PS2 controller with an USB adapter out of my junk box. Knowing that the analog controllers also work with potentiometers, I found my victim. After removing the screws in the back I started warming up the old soldering iron to completely void the long gone warrantee on the controller. Now all I needed to do was attach two wires connected to the thermoresistors, solder the wires to the point connected to the potentiometer and that is pretty much did it. Given there are two sticks with X and Y axises for both you could have up to 4 temperature sensors (I chose to go with 2) The controller did does have one feature where it automatically turns off the analog control after no use for a couple minutes. After thinking about some more complicated solutions, I went low tech by forcing the L2 button to the on position by applying a piece of electrical tape over it.

I won’t go into the gritty details of the software to actually get the numbers from the joystick since M Harris has already done that so well on his CodeProject writeup.

Last comes calibration, when I purchased the thermoresistors they also included detailed specifications on the tested resistance values at various temperatures, which with a little bit of physics and some fun math, in theory I could have avoided the whole calibration but given the length of wire and/or my sloppy soldering could skew the accuracy of the temperatures I opted for a more manual approach. I put my “thermometer” in a plastic bag along with my trusty $5 digital thermometer and dropped it in an ice cold water bath, while recording the temperature changes as the temperature increased to room temperature. I followed this by doing the same with hot water bath until it lowered to room temperature, recording values as the temperature decreased.

With this data I entered it into Microsoft Excel and got a nice graph (see below) which gave my nice magic formula of:
Temperature = 0.0059(joystick X Axis position) – 138.57

By simply doing the math I now can capture values on my PC.

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Propagating peppermint and lemon verbena – UPDATE

16.5 years ago lemon verbena, peppermint




As you can see from the picture, my peppermint and lemon verbena propagation has come a long quite well. I did have a little aphid infestation on the peppermint plant which I attempted to take care of with manual pinching, but eventually I gave up and chopped off the top off the plant. I then followed up with a hefty dose of insecticidal soap to the soil and the remaining stem. I would have preferred an even more natural method such as ladybugs but sure my officemates would prefer I didn’t.

The lemon verbena did pretty well on its own with one exception I think I mistakenly broke or cut the top off the plant so there was no vertical growth and just crazy shoots horizontally so I cut most of these off and replanted to 3 new starts which have taken off as well as their parent.

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Fall Strawberries

16.5 years ago strawberries

I really like the color of these strawberries I propagated last this summer. I still have to figure out what I am actually going to do with these.

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Halloween Berries

16.5 years ago halloween

My oldest daughter coined the name “Halloween Berries” this name a couple years back as the leaves fall off exposing the hidden berries right at Halloween every year.

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Getting the garden ready for winter

16.5 years ago garden maintenance

The leaves are changing and falling the days are getting colder and I am personally coming to the end of my vegetable growing season. I do have a few post season activities before I completely call it a year.

Remove plants: Now my plants have lived a good life but now need to be removed. I mulch my lawn so I am always lacking greens for my compost bin so this is a good time to get some new materials. Most of my remaining plants are tomato, pumpkin, and cucumber plants which have some tough skins so I will chop them up with my lawnmower prior to add them to my modest bin. While you have your mower running this is a good time to let it keep running until it runs out of gas to avoid gumming up the engine when you fire it up next spring. This is also a good time to inspect and sharpen or replace the blade since if you are like me you will completely forget about this when you finally get around to mowing next spring.

Fertilize: If you only can fertilize one time throughout the year now is the time because turf grasses have the ability to store food during the winter months to allow a very quick rebound after the winter months. My primary concern is for my lawn which I am applying alfalfa pellets, since we have had some intense rains these past weeks they should break down quickly and not have the appearance of goose poo for too long. While applying I also allowed some to fall into by beds to help microbial activity and give my empty beds a head start for next spring. Be sure to avoid beds with and vegetation since you want to avoid any new growth with first hard freeze coming up.

Turning the soil: This can be a controversial activity since messing with the soil can inhibit microbial activity though turning the soil now can give you a head start next spring. My motivation is more on the lines if killing baby slugs (I know I am cruel) The slug activity in my garden was pretty minimal but I have concerns the few visitors may have decided to raise a family in my bed for next year. If I simply turn the first few inches of the soil I can expose the tiny slug eggs which birds will eat as a snack and any remaining will be destroyed during our first good frost. As an added benefit this will be a good time to catch up on my slacking in weeding during the last few weeks.

Taking care of your tools: Now is a good time to find those missing tools that may be hiding in your yard and garden. I have no idea why manufacturers choose to make these things green; almost like they want us to lose them to buy more  If you find any of your tools it is a good idea to put a light coating of oil on metal parts of your tools. You can also apply some Linseed oil to the wood portion of your tools.

Frosting on the top: At this point my garden is looking pretty good….even tempted to start planting though I will resist the urge. I have a plan to hold me over this winter but that will require its own post. After I have had a couple good frosts to kill off any slug eggs I will break open a couple of my bags of leaves and spread on a solid layer on top of my beds. Not only will this provide some food and temperature protection for the worms in my garden but whatever remains will be a great addition of organic matter for my garden.

Now with all this work I should be ready to start gardening way earlier than I should next spring…will I ever learn.

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