My Silly Pondcam – Part 5

This is my 5th post on Pondcam and I think things are really coming together nicely. We have our waterproof case figured out (I think). Our 24×7 Pondcam light is well underway with a plan to make that work.

I want to start finishing up what will be the top of our camera cover. A couple of weeks ago my dishwasher died. My wife picked one up at Menards and I had to install it the next day because we had a showing that Saturday. I was really ticked off by this and in a bad mood all day because all I wanted to do was work on Pondcam (There was a lot of swearing involved, mea culpa, as I have a two year old that repeats everyting) . Even then I was obsessed with this project, so while I was buying hoses for the dishwasher (Which leaked from the fron’t door after I was finished installing it and the manufacturer couldn’t tell me why, so we have a repair man coming out tomorrow to fix it), I bought one of these to screw into the top of our Pondcam Case.


As you can see the hole in the top is pretty big. Here is what we are going to stick through that hole:

1) Wireless antenna cable.
2) 12 volt power from battery/solar panel.
3) Ethernet cable.

I know what your are thinking. Why does he need an Ethernet cable? Well the problem is that once I glue the top on… yes I really need to glue it so it is water tight. I can’t use a gasket and screws because my tolerances on those parts are not precise enough. Once it is glued, it will not come apart again without a lot of trouble and re-gluing. Now think about electronic devices like that. Sometimes when you upgrade them, they go back to their factory defaults. It won’t matter how good my antenna assembly is, it won’t connect, then I will have to bust it open. But if I have an Ethernet cable, I can just plug it into my network inside and reconfigure it, then we will be back in business in no time at all. No pulling it apart, not waiting for it to dry for a day after gluing it back together.

You may be thinking another thing, I can see that he will feed those cables through, but then what? Well, when I was looking through my plumbing bin while working on my dishwasher, I found this. I thought to myself, I should really use some of this in my project.


I am going to cut a length off of this and bring the cables through.

I drill a 3/4″ hold in the camera top plexiglass. I grip the brass fitting with some vice grips and heat them up with a torch. I screw it in place, the hot brass melts the fiberglass just enough for me to screw it together easily. I add some epoxy around the seal that would be on the inside of the case. Now we have this.


I feed our antenna cable, a nice long length of cable for power and our Ethernet cable through. I still have to crimp and test the Ethernet cable at both ends, but for now this top is pretty close to ready.


This part is done and has to wait until we are finished figuring out everything else before we glue it with the camera housing with everything inside.

Finishing that part leaves me with some time to look at our resistor bug. If you remember we started building that in an earlier post. I watched the series “Lost” and I know that normal people really hate loose ends in a story so I will try to clear that up right now. That glue we put on it from Post 4 (or was it 3?) should be dry by now. I pull it off the clamp, twist two of the terminals together and curl it up to look like a scorpion tail. I bend the other two on the opposite end out like they are some sort of hands or claws, then I bend and clip the final three pairs in the middle to make them look like legs. Here is what we have.


Oh… I hate this thing it gives me the creeps. It really is ugly the way the translucent glue dried over the resistors making it look like you can see its gross insides. I may not use this to scare my wife. My two year old on the other hand gets really grossed out by bugs and she has this neat nervous reaction where her whole body trembles for just a second like she totally gets the heebie jeebies. I may show it to her and let you know what she thinks.

Note: I need to interject something here about my wife. She really wants to sell the house we are in. She can’t stand it here. Like a lot of people, our house has been on the market for over a year and a half and the only offers we get are LOW LOW LOW. She is very stressed about this and today we decided she would have a relaxing day on her own so she could get a massage and just relax. I spent the day with the kids and worked on non-pondcam things like riding bikes and filling up a blowup swimming pool. So, in short, I would love to put this ugly resistor bug under my wife’s computer monitor, but I won’t… At least not today.

What is next? Oh that is right, we are actually going to have to buy some stuff to finish this project. I wanted to use as many of the parts from my many bins of mystery as possible, but we really need a few things from the store.

Here is my shopping list:


The first thing, more flexible wire. I really don’t like any of the wires I am using. If I want to do more projects like this one I really have to have equipment that works well. I will look for better wire for this project… Oh… And new probes for my meter (I totally know the cables for the meter are going to be expensive, probably more expensive than I paid for the meter when I bought it, but I don’t care. I need this stuff to work well).

I need a photoresistor. I could take apart the one from my daughters Snap Circuits kit, but that is my favorite toy she has. I always am super careful with it and more religious about putting it away and counting all the pieces than anything I own. I don’t want to mess with that, that toy belongs to both of us and it is my total favorite.

I need a good 12 volt battery charger for car batteries. I need this not only for my non-geek life, but also for this project. I have some ideas of the type of charger I want: 1) I want it to not get “melty” like my last one if my wife or sister (or daughters in a few years) connects them to their cars the wrong way. I also want it to show me when something is charged all the way. It has been a really long time since I bought a battery charger for a car (like 20 years) the last one I got was a present from my mom. So we will have to see. Lucky for me Radio Shack and Advanced Auto Parts are in the same strip mall.

Last we need some resistors. I am thinking some good variable resistors for our 24×7 light assembly. We have to make those transistors act like switches (When we feed current into one part of the circuit, it needs to dump a ton of current to our light). I could buy a transistor that acts like a switch instead of like an amplifier (remember how the light would turn brighter the more light I allowed to get to the photoresistor, I don’t like it that it was doing that), but I am kind of on the fence on that a little bit. This is more of a maybe I will buy some resistors until I think about it some more.

So I go to Radio Shack and there is a nice lady there that offers to help. I tell her I am looking for photoresistors. We look around the components together and I see this!


This is not just one photoresistor, this is a bag of like six of them and they are three different kinds. Oh… I’ll buy this in a heartbeat. If I don’t like the way one behaves in our circuit, I will just try another.

Next is cables. I want some really good ones. I really don’t care about the cost at this point. I just want the best cables I can find. Here is what I buy.


It is the most expensive kit they have. I learned in my first job as a bench technician that good test cables are as important as the meter. The few I have left from those good old days and have been hacked up and/or lost. These look OK, so I buy them. They have alligator clip and probe ends. I will probably cut them up and put new ends on them eventually, but for now these will do just fine for the rest of this project.


I know the automotive store is like 50 feet away from this Radio Shack, but I would rather get my battery charger here if they have one. So I ask the lady for a “battery charger for a car”. She takes me to car chargers for cell phones. I explain to her what I want is not a car charger for a cell phone and a charger that literally charges car batteries. I am getting a little frustrated because she doesn’t understand me (I find out later that it is all me because I am so old). I am the only one in the store and she is willing to spend some time with me to help me find what I am looking for. I tell her I would just look around a little. Then I see THIS!


Every single thing about the face of this package makes me so happy. Do you know why?

As I am writing this, I bought this device two days ago, I still look at this package and it make me really happy. This is like a key… A key that has potential to fix all of our power problems. Yes… I know… I know… but, “you said you weren’t worried about power”. I was being a Pollyanna. I have been worried about power since the middle of post 2!

Just read it. I am going to break a blogging rule and just for a few lines I am going to put things in capitals:


And guess what else? As I check out, the lady tells me that I can get a free  adaptor for this for all kinds of outputs (It is on the package face, I didn’t notice it). I look and… there is an adapter that fits the back of our camera.

This thing is so cool that I can’t stand it. I forget all about the resistors I wanted to buy for our light assembly and just go to check out.

As I check out and am paying for the pearl I just found, she asks, “Sir would you like to buy the extended warrantee for this cell phone charger?”. Like a real geek I look her right in the eye and with a serious face and say, “No, I am going to void the warrantee as soon as I get home by busting it open and cutting all the wires”.

Note: This “charger” is so perfect for outdoor applications with 12 volt batteries and solar panels, I go back the next day (which was today) and buy another. This time I buy the exact same charger, but with a mini USB adapter so I can make my Raspberry Pi run outside with our solar panels. The Raspberry Pi is a full blown computer that runs on a little board (And on 5 volts just like our camera). Oh… I so want to put my Raspberry Pi outside (I am waiting to think of an actual reason to do it). You can read more about one  of  those here. I won’t be bringing the Raspberry Pi out in this project. At least I hope not.

So the next stop is Advanced Auto Parts. I need a “car battery charger”. I think this is a simple thing and an automotive store would have one. I go in and look around and I can’t find one. I look in the isle that I think it would be in and I don’t see it. At this point I am a little irritated because I can’t find what I am looking for. I must be the worst customer in the world because I was in the right isle, but I was looking for things that looked like my old charger. Older guys would know what I am talking about. Packages that show big transformers and big clips at the end of big beefy wires. I am thinking if they wanted to let you know about the charging capacity of their charger, they would have something on the package that meant, POWER! to charge your batteries.

So I give up and ask for help. I ask the guy for a “car battery charger” and guess where he sends me? Yes. He sends me to the car chargers for phones. Only then do I realize it is me. I am the one that is broken and can’t catch up to the times. It shouldn’t be this way. I am an IT guy… I have an iPad (granted it is a children’s toy in our house), my wife has an iPhone, I have an Android. I build complicated enterprise scalable computer networks for a living. My finger should be on the “pulse” of the technology even in an auto store (And especially Radios Shack), but alas… I am too old. A “car battery charger” doesn’t mean “car battery charger”, but “phone charger for a car”.

After I realize this it becomes crystal clear that me and the young kids that work at these places don’t speak the same language. So I ask in a different way, “I would like a battery charger that plugs into an outlet from my house and will charge a battery that goes in a car”. Bingo! The kids tells me, “Isle 3”. I am a little irritated that he doesn’t help me find it like the Radio Shack lady did, but what can I do? It is probably my fault for being too old and blind (it was the exact isle I was in looking for one… you know the isle I am talking about… The one with all the car batteries in it).

Now I want something beefy that will work for a long time. I look at the different packages and I see nothing that stands out. I pick up some of the boxes and they all seem so light. This isn’t anything that I am used to. Nothing is right (It has been twenty years or more since I was interested in anything about cars, so I really am not understanding how close automotive gear has gotten to my regular field). I am looking for something heavy, with big masculine pictures on it, you know what I am talking about, tough guy stuff. Big clamps to hold those batteries, those should be all out in your face on the box. Oh and a big arrow pointing to the transformer and tells you how much it weighs. I am really confused, has it been that long since I swapped out an engine (I have done that when I was a kid) or a transmission (I did that too, twice and once without a transmission jack when I weighed 135 pounds on a van)? I am pretty sure I am in the twilight zone because the one thing that I thought would take way more time to change was automotive and power, but alas… It has succumbed to geekdom.

Here is what I buy.


The box is so light I can’t believe that there is anything worth squat in there. I don’t like the box at all. The other boxes there were all very light too. I do like that it has “10 A fast charge” at the top though. Maybe this will be good. Look at the picture again, why are the little clips all orderly and sitting next to the charger like that, if I designed this box those things would look like massive chompers that would going to jump out of the box and tear your eyes out. And for the “speed charge” on the front, I totally would replace that with, “LIGHT weight, but GUARANTEED HEAVY POWER!!!”. No wonder I was in that isle and couldn’t find them… This box is designed like it has a flashlight in it.

So I have my “battery charger that plugs into an outlet from my house and will charge a battery that goes in a car”  which can charge any 12 volt battery in my house or car. I have my “car battery charger” which in my native language is a “step down DC transformer from 12 volts to 5 volts”.

I am so close I can feel it.

First I continue to mess up my workbench and pull out what I will now call our “battery charger” (I can’t use the new lingo it is too difficult). I hook it up to our first battery (I didn’t keep track of which battery I was using in all of the excitement of  getting the camera going outside), I am not sure which one it is, but I connected it and let it charge while I worked on other things.

The charger has a fan in it and it made all sorts of noise when I connected it. The fan went on, then went off. It has a little light on it that show when it is connected to the battery, that light did light up, but nothing was going on. I read the manual and it describes how battery chargers work these days. It says several thing that are really really cool. One of which it won’t “spark” like old fashioned battery chargers when the terminals are touched together (That is good to know, so I didn’t try that). It can sense when a battery is connected and only when it “sees” a battery connected well it will actually charge. My gosh!!! This thing has been designed so my sister and wife can use it. I struck gold twice today!!!! This sucker is fool proof. Actually it isn’t that fool proof, because my instinct is to open it up and see what is inside it and figure out how that all works, but I am no fool, but I may be one in the near future.

I mess around connecting batteries and find out that only one of the ones we were using actually works. Here is a picture of me charging it. It is hard to see, but this little lightweight has some serious power and a meter to tell us if our batteries are actually charged (It pretty much has every feature I was hoping for and more in a “car battery charger”).


This battery is the last one (I think) we had out in the yard with the solar panels. It is the one that I ended up using for some of our earlier tests. When I attach it to the charger I can see pretty quickly that it is measuring 75% charge. The other batteries I tested just made the charger turn on and off the fan, it would say a battery was connected by a light on the front, but no matter how long I left those other batteries on, it would just do the same thing…. A whole lot of nuthin’. I label the dead ones as dead and bring them to the garage, no more getting these guys mixed up.

Now the moment I have been waiting for since I was at Radio Shack and ran into our “happy accident”. Let’s bust that car phone charger open.


Oh that is pretty. It is small too, small enough to fit into our case I bet. I am going to pull it all the way apart and put it next to the camera to see what we are dealing with to attach it.


I am really excited and start to visualize how this is all going to fit together, but first I need to do some tests. I am so confident in this device, I hack up the output cable and attach the correct power plug that will fit directly into our camera. I really try to do a good job on this cable because I want it to last, so I solder it and tape it over with electrical tape. While I am looking at this device, I see a switch on this and can’t figure out what it is for. So I look in the manual.


The switch changes the mode of the charger from a USB type charge to a “regular” charge. I am not sure what the difference is and I switch it back and forth during this voltage test below. The  reason I am checking the voltage is I have to make sure it won’t kill our camera before plugging it in, I also have to make sure that the polarity is right… Otherwise things might get a little smokey in my workshop.


While I was looking  at the function of that little switch in the manual for the car phone charger, I see this.


Look at the top, the input is 10 to 24 volts. This thing couldn’t be more perfect for our application. Remember the output of the solar panels?


See that Voc 24 volts at the bottom. That is pretty good. I do notice that Max Sys V: 50 volts. I never saw those panels put out anything like that when they were out in the sun, so I think we are in good shape.

Now this next test is the most crucial so far as it relates to power. I am going to stick an ampmeter between our battery, the car phone charger and connect its output to our camera. This will tell me how much current it uses and give me a much more clear idea if the solar panels we have will work to power up this whole system.


I almost don’t believe what I am seeing. The draw from this device at 12 volts output is miniscule. It is 100 milliamps. This is really low. The power device does EXACTLY what I was hoping, it is not a regulator that simply dumps the extra power in heat, it truly converts the power. Take these power formulas into consideration:

We know Watt’s Law:

P (Watts) = I (Current/Amps) * V (Volts).

Our minimum power output from our solar panels is 4.5 watts. Let’s say it is sunny and we are seeing it output 20 volts. I have seen that and more when messing around with those panels outside. The formula we need to solve is this when figuring out how many amps of current the panels would produce.

4.5 = ? * 20

I plug this into the calculator:


Now let’s do the same math of what we are actually required for our camera. We know it is 5 volts and uses 300 milliamps.

P = 5 * .300

Power for the camera is 1.5 watts. If the regulator is burning away all that extra power in heat (yes that little sucker got super hot, I thought it would burn out) we are losing 3 watts of energy. Also, If we think about it a little more, it is possible that our solar panels to turn on the camera needs to be in full sun because .225 amps won’t run our camera, or better put, it may run the sound function of the camera and the connectivity, but not the actual camera part. Remember this picture that was so frustrating for me from post 2? Even when I tried to get past this with batteries, it didn’t work. We know now that two of them were broken.


Next I need to mount this power supply to our camera (It is no longer called a car phone charger). I use some Goop glue and just glue it to the camera. This is how it sits now in my workshop.


Man… I can’t believe how perfectly these fit together. I have to stop here. I am having people come over today and I have to buy food, drinks and clean. As for cleaning… I think I will start here…


To continue reading see post 6.

6 Thoughts on “My Silly Pondcam – Part 5

  1. Tim Willis on July 24, 2013 at 8:55 am said:

    Car battery charger???…learn the lingo! lol. Makes sense to me, but I’m old too.

    Getting close. Get everything in that case and seal the leaks.

    By the way, I had to Google Pollyanna, as I had no idea what that meant. An interesting little tidbit. I might actually read it!

    • I saw the movie when I was a kid. I only remember a part where she was trying to convince some grumbling people that Sunday was a good day. A friend of mine that used to work for me said once, “The best thing about Friday is that Monday is only three days away.” Yeah… That guy was a Pollyanna.

  2. Pingback: My Silly Pondcam – Part 6 – Light? | Joe's Lab

  3. Paul on July 26, 2013 at 8:59 am said:

    You should have opted for glass tupperwear with a clamping lid for the case. I can send a pic of one of my wife’s.

    I’m confused: Are you using the battery or the solar pannels to power it?

    Maybe consider putting a resistor in between the stepdown converter and the 12-24v power to reduce the voltage to reduce the waist in heat?

    • Oh I hope you are not right about the Tupperware thing. If water gets into this case and breaks the camera, it will be really bad.

      I am going to use the battery and the solar panels. The idea is that the battery will be running the camera for most hours of the day, then when the sun comes up it will power the camera and charge the battery at the same time. When it is night, the sun goes down… And the battery takes over (At least that is what I am thinking).

      Also, there is no heat problem any more. The “car cell phone charger” steps down the voltage in a way that conserves energy and reduces heat. I can think of ways to do that, but not sure how that one actually works. I am just glad I didn’t have to build one.

  4. Pingback: My Silly Pondcam – Part 4 | Joe's Lab

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