Fix-it Friday: Blank Laptop Screen

As I was preparing last week's post I heard a crash behind me and turned around to see a surprised 10 year old no longer with a laptop on her desk.  So we tried turning it off and on again, no dice.  I have a spare monitor for my Raspberry Pi station so we plugged that in to see if it was the whole system or just the monitor.  It worked! And with the external monitor she could use the whole computer normally so that is a good sign.  I tried toggling the monitor settings with the function keys and the windows menu, no good.  The good news is, it is just the monitor.

There might be hope for the patient yet, the next question is if the monitor is broken or simply a wire came loose.  Let's test the camera, that doesn't work either.  That makes me hopeful it is just a loose wire somewhere.  To the tiny screw driver set! I took off the bottom first, hoping the problem was in there, but everything looks in order.  

The monitor cable is in the bottom left of the image by my finger.  Looks and feels secure.  Ok next is to take apart the monitor.  Mine had these little rubber nubs that were hiding the 1,000 tiny screws that hold the monitor in place so I first removed them and then unscrewed everything.  Then I gently pried the plastic cover off like I was taking a tire off of a bike to get to the tube.  Two screw drivers gently tugging until it popped the plastic nobs without (hopefully) breaking them.  Got it! 

As you can see, I had a little oopsy in the top left corner, hopefully it won't be too obvious once it is up and running again.  Nothing obviously wrong here, but lets follow that wire in the bottom left and see where it goes.  A ha!!

Doesn't it look like there should be a wire plugged in there?  Well there is, this is a terrible picture, but it is a loose wire.  So I plugged it back in and put the monitor back.  I gently placed all of the covers back and booted it up.  Bingo! 

What a generic, boring background my daughter has.  I mean it is a beautiful image, but I think I can do better.  I have to test the camera anyway so... 

That's better, now hopefully that will be a daily reminder to be more careful with the only laptop we have.  Just in case you want it to be your background too:

I wonder what is in store for next week. 

Fix-it Friday: Clogged Vacuum Cleaner

The patient presents with a red indicator, indicating a clog.  So first we do what the instructions say and clean out the filter and let dry completely.  Since I thought this would be it, I didn't take a picture.  This is usually the problem, but this time with the completely clean and dry filter assembly, still red.  So lets take it apart.  Most likely place for a clog is in the bottom:

 If you look at the image carefully there is a pro-tip from the manufacturer: "Use a screwdriver to take out the screws."  Thanks Hoover, I couldn't have figured that out on my own.  After unscrewing the screws with a screwdriver (who would have thunk?) the problem becomes clear:

Look at that big ugly piece of fluff, let's take that out.  Hmm, there seems to be more stuck in.  Ok let's take off the back hose and cram something in there to get it out.

 Now we are cooking with gas.  After I pushed as much as I could out with the stick, I pushed an old ethernet cable through so that the pokey plug in bit could grab any stragglers that were left behind.

Yikes that is a lot of fluff (and one lego, score!).  Let's clean off the string/hair/thread before we put it back.  Ah, that's better:

Now to reassemble and test and it purrs like a kitten.

I wonder what we'll do next week.  

Break to Make: CO2 Detector Take 2

As we saw last time, I made something fun, but not very useful.  So let's make something useful today.
The Problem:
My daughter is not in school right now, as you may have experienced yourself.  At her current age, she isn't supposed to have very much screen time, but almost all of her work is online now so we decided to set a limit of 30 minutes of screen time and then a break.  With me working and my spouse taking care of our other little one, who is watching the clock?  The answer turned out to be no one.  I could set a timer on my phone, but that wouldn't be my daughter taking responsibility for it so what can we do?
The Solution:
If only we had a buzzer that I could make a timer out of.  Didn't we have one by the albino the hidden alarm?  We did, what I wouldn't give for a holocaust cloak a button switch and an LED.  That's right, observant readers will remember they were both on the CO2 detector that we didn't use.

So after a quick desoldering, we have them.  But that little blue button is not very attractive, I'd rather it have a topper like these nice ones from Adafruit.  Let's check Thingiverse first, this one looks perfect, but it is for the wrong size button.  Let's print it anyway and scale it to see, nope the middle is all mushy.

Now, on to OpenSCAD! My calipers say the small blue button is 2mmx2mm and the Adafruit site lists the size as 12mm, so a big cylinder (r=6mm) for the outside minus a cube (2mmx2mmx2mm) for the inside.  Done and done.

Doh! 2mmx2mm is exactly what the button is and the actual printed size is too small.  Let's try 3mmx3mm.  Bingo (file on Thingiverse).  

Now to put it all together, a button, an LED, a buzzer and an Arduino, now we can make a timer.
So I was thinking, push the button and set a 30 minute timer.
if (buttonState==HIGH) {
    digitalWrite(ledPin,HIGH);
    delay(1000*60*30);//1000=1 sec, 60 sec in a minute, 30 minutes total
    playMelody();
    digitalWrite(ledPin,LOW);
} And to test! 30 seconds? Let's check the math, 1000 ms in a second * 60 seconds in a minute * 30 minutes, right?  Yes.  Hmm a cryptic warning from Arduino: "More knowledgeable programmers usually avoid the use of delay() for timing of events longer than 10’s of milliseconds."
Interesting, it seems like there is an overflow problem.  So lets delay for 1000 (1 second) and count up to 1800.  And it works (code)!  So next we cram it back into the CO2 detector shell.  First, I cut all of the unnecessary plastic bits out, then I got my tiniest breadboard.

And did you notice? There are three AA batteries, 1.5*3 is 4.5V which is within the power requirements for Arduino.  So a quick solder for that and solder the wires to the buzzer to save some space and Voila!

I had to cram some thick paper in there to make the button stick out and I accidentally broke one of the clips so I had to hot glue it, but other than that we are done.  The wires are rescued from some old ethernet cable I had laying around.    

And now, we come in at 29 minutes and 59.5 seconds.  

Well this time, it is both fun and useful.  Hooray!

Break to Make: CO2 Detector Take 1

Hello Friends, today we will make something new out of an expired CO2 detector.  First we take out the batteries.

Ok, now the screws, nope, no screws ok, there are little plastic tabs holding it in place.  If you can wiggle them gently and cram a little screwdriver in there we can take the bottom off and it will easier to put back together.  I also flipped the circuit board over to get a better look at the components.  Voila:

That looks like one honkin' big buzzer, lets see if it works like a regular buzzer.  It is Arduino time. First load toneMelody onto your Arduino (File -> Examples -> 02. Digital -> toneMelody) which plays the catchy jingle, "Shave and a haircut, two bits." Apologies to those who are more familiar with the inappropriate version which I will not repeat here (for the curious, the second to last word is madre and a description can be found on the Wikipedia page for "Shave and a Haircut").  Anyway, where was I, ah yes, if you have a buzzer or speaker laying around you can test to see what it sounds like by connecting pin 8 (usually) to the positive and ground to the negative.  The Arduino Tutorial page has a good description.  Next is to get two longish jumper wires, one in pin 8 and the other to ground.  We are going to have to flip the board back over to get at the pins for the buzzer:

You might have to flip it back and forth a few times before you find the right ones, they are larger than most of the pins in the area and mine had three (one is being touched by the blue wire in the above image and another is by my finger).  Pick two and apply the wires, did it work? Try flipping the wires, now? Try different pins, and? There are only six combinations with three pins (3 choose 2 = 6) to it shouldn't take too long.  Also, you might want to adapt the toneMelody code to play on loop so you don't have to keep hitting reset on the Arduino and hold the wires on the pins at the same time, but it isn't absolutely necessary.  Success!

Ok, so now we heat up the soldering iron.  I can't figure out how to hold my phone and the soldering iron and the CO2 detector all at the same time without burning myself so no action shots, but basically I took a smallish screwdriver and gently wedge it between the buzzer and the circuit board then on the bottom I put the soldering iron on the leg closest to the screwdriver until it is melty and moves.  Then I move the screwdriver to a different spot and repeat until all of the pins are out.  Got it:

Let's just double check that we didn't fry it.  Also, I switched to M-to-F jumper wires now that it is off the circuit board.

Score! Now we are ready to make something with it.  I happen to have a photoresistor in my Arduino kit and you probably do too so I thought it might be fun to make an alarm.  The photoresistor tutorial is here.  We can add that to the breadboard and set up a simple trigger.  To minimize fiddling I set the baseline value to the ambient lighting on reset and then the trigger will be when it gets at least 90% darker.  If you don't want to figure it out yourself, the code is here. Testing:

Not too shabby.  And now to cram it all back into the base and test. 

Well that was fun and a little silly, but not very useful...  

New Chapter

Hello out there my faithful and few readers, I am now at Sacramento City College.  Because of the social distancing, I'll put some Maker Friday posts as part of Sac City's Makerspace.  Which I am the co-co-coordinator of.  More to come soon, including Fix-it Friday, Break to Make, and more!

I have been working on these for a few weeks now, yet you see nothing here.  While you wait patiently, check out these Arduino projects I made for our "Pathways to Paychecks" events for High School students: djArduino, moodLight, and the ever popular arduinoTwitterBot.