Arduino + IR Detector = PC Remote

So on Monday I received some mail which included the RTC chip from my last post, and other things such as  some Surface Mount capacitors for my Arduino Clones , and a little IR (infra red) detector. I think the one i have is made by Sharp but i got it from Jameco.com (part number : 2129844)  but i also had one i got from radio shack which is the one shown here and the one i used for this project.

Not to be confused with another product that radio shack offers which is an IR transmitter packaged with a phototransistor. Anyways the good thing about this as oppose to regular phototransistors is that while both are extremely sensitive to infra red light this one has some sort of "decoder"  that filters out any other infra red or ambient light that is not modulated at around 36-40 khz which is what most remote controls for electronic devices use.
So once the IR detector recognizes a certain frequency of light then it outputs , i guess the raw code so to speak. However this great man by the name of Ken Shirriff wrote a library for these detectors to use with an Arduino.
So with that library on stock along with my Arduino and Visual Basic I ventured on to make a remote control for my PC. The concept is simple. the library provides a record function, in which you wire the detector to your arduino and then get a remote press some buttons and it prints to serial the code. So if i press volume down on the remote and it gives me a code like FF4AD, then i send that to serial, while i have a visual basic program waiting for data on the same COM port as my arduino and it checks for certain codes, so if it receives the FF4AD code then i know that button was volume down so then i have it send some "send key" functions to my pc to turn the volume down. Of course i can make it do anything but obviously if i press a volume button im going to make it adjust my volume which is basically all i wanted because sometimes i am in  bed listening to music and i want to change tracks or turn down the volume but too lazy to get up.

To the far left is the IR detector connected to an arduino clone which is connected to  a USB serial interface and then the remote which actually controls a speaker bar i have on top of my tv but now it also controls my PC :)

Okay i was about to post the Visual Basic code as well as the Arduino code but it looks very messy here so shoot me an email or send me a message on here if you want a copy of the Sketch and Visual Basic form. Here is the link to Kens site.
Ken Shirriff Arduino IR library

the only set back i had which took me about 10 minutes to figure out was that while sending the code to serial with Arduino Serial.println(FFA4D); and then receiving it in Visual Basic there was an issue, VB was not responding to the code , so i had VB echo back to me what ever it was reading from serial and in fact it was FF4AD  but when i pased an if statement saying something like if code is FF4AD then do this, it was not doing it and i could not figure out for the life of me why it was not doing it.
Then it hit me when i send a println command from Arduino it adds a line terminator at the end , and when echoing this on VB the line terminator is invisible but it still is there so "FF4AD" is not the same as FF4AD/n" and thats why my if statement was doing nothing, so a simple change to print instead of println was all it needed.
Here is a very ugly video of my showing it off.
At first i am showing you an indicating led that just flashes every time the Arduino receives some IR codes.
After that i open up Visual Studio and i execute the program, which is just some buttons i made at first to test out the send keys functions but are no longer needed since i have the code running on a timer instead of pressing buttons, then after i run the program i start to type in what COM Port i am going to use and then i show you the volume going up and down as well as mute. the actual volume control does not have to be open for it to work i just used it to show you and the window of the VB program does not have to be in focus either i can be minimized or even hidden on the task bar and it works just fine.

In the future  i would like to make a universal programmable remote. Using Kens Library to read codes and then save them on either on or off board memory and then use that to send them out to the waiting device such as a TV or stereo. I would like to make it a touch screen remote using the Nintendo DS touch screen which has already been used with the Arduino since it a very simple 4 wire screen , X Y ground and power. I would like to have some sort of LCD screen under it to draw buttons and menus but i think that is beyond my reach right now. So basically I will just use some nicely designed paper  with text such as volume down or up and mute and what ever other functions  i want to use it for. then i will overlay the screen on top of the paper. After that proceed to check the X and Y coordinates of where the buttons are. for example if the Volume UP text is under the screens 23 , 78 then I will make Arduino send out whatever code i recorded for volume UP when i press on that general area or proximity because it is hard to press an exact spot with a finger tip so it will be based on rangers/ thresholds of  coordinates. The nintendo Ds touch screen , or rather digitizer is only $9.95 at Sparkfun , i forgot to mention its a transparent little thing that is how i will lay my button drawings underneath it. 

 You might also be wondering how you will connect that little thing to the arduino , well they do sell a breakout board that you plug that little strip into which connects to 4 nice big and spaced out pins that you can use . But to save some cash you could just grab a blade or exacto knife and cut through the strip to separate the 4 wires and then solder some longer wire or pins to the tips. I dont know what ever floats your boat, or mine in this case.

Father Time

So i got my RTC (real time clock) chip today,  the nifty little DS1307 (Jameco part number : 1194679) , seen right next to a 3v coin cell batter ( 14162) and battery holder (355434). I ordered this i think it was on friday and got it on monday, not too shabby.

So I wired it up , i am awful at understanding datasheets but this one was pretty simple.  Where X1 and X2 is for a crystal/tuning fork which i also got from Jameco (325244) I basically Looked at the Ladyada tutorial for the RTC and  ordered all the parts except the breakout board because its not necessary, it just for looks in my opinion.
The Ladyada tutorial is here.

Aside from the power , ground and crystal connections i was not quite sure where everything else went. then somewhere alone the lines , i do not remember where or else i would give proper credit, i was directed to the Arduino  Wire  library which is how Arduino talks to "I2C / TWI devices" Then right there in the second sentence it said that "SDA/data line" is on analog input pin 4  and the "SCL clock" line is on analog input pin 5. After my enlightenment i pulled up the RTCLibrary which to be honest i dont know if that came with Arduino because i have quite the collection of Libraries that i dont know which are the ones that came with the IDE. If you would like a copy of my libraries send me an email i can use to send an invite for my DropBox account so you can share my files.

My Original idea was to make a clock with a custom built Arduino
to fit inside an acrylic case, which i would of course make my self.
The coolest part is those digits you see right there are are Russian Vacume Florecent Displays, which if i am not mistaken are no longer in production, theres only whats left from the old days.
Another problem is that these babies are very high voltage devices im talking 50-70 volts. Thats something i am not comfortable with yet.
Not trying to burn the house down. Or worst hurt my self.










So i will have to settle for some new school 7 segment led display.
Anyways back to RTC chip, its pretty straight forward, you include the RTC library call a " now.hour() " function and it returns the hour. The chip has a way of converting from 24 hour to 12 hour modes which do not know of yet but a simple if statement can solve that as well as the Am or Pm conversion. 
If you connect the 3v coin cell batter to the chip it can keep time for about 5 years. So if the battery on my Arduino or power source gets unplugged as long as the 3v batter is still connected to the chip it will keep time just right so when i turn on my Arduino again it will be on point.

My next project hopefully start and finish this same weekend will be adding ambient lights to friends car. She wants lights under her seats, something subtle  not too fancy or bright. So lets look forward to that.

Beyond Bare Bones Boards ....

The very second after i finished building my first Arduino bare bones clone I already knew what could be done to improve on my design. A member on the Arduino forum also gave me hints as to how i could improve the design after i posted issues i was having with this new board and the timing being off. I will admit the board is very unstable..when i upload the Blink sketch it blinks at about half the speed instead of once per second i notice its at about once every 2 seconds which means it might be working from the Atmegas internal oscillator and not my external crystal. Now this could be because of my soldering which is very bad and possible cold joints.  Now if you look at my pcb design towards the bottom you will notice  i basically connected the ground of the ceramic capacitors leaving my crystal together , along with the ground of the reset button and the extra grounds headers i added. this is called a daisy chain and it is not at all a good idea.  Sometimes my clock speed is good and sometimes it at half speed so the board is very unstable. but then again it could be my soldering

Now below is my second version of it, I was advised to make a fat trace connected to ground,  and anytime something needs a reference to ground just connect it to the fat trace and not together with another  lead that is going to ground I also decided to reference the ground from the capacitor after the regulator instead of grabbing it from the regulator itself  like i did before, i figure since in real life electron flow is  from negative to positive then i might as well grab it from the capacitor after its been regulated and smoothed out . This is exactly what the man on the forum said
"I'm not seeing a .1uF bypass capacitor going from the VCC on your chip to GND. (edit: I just spotted it, it wouldn't be filtering/bypassing that far away from your VCC Pin, it's effectively not there doing it's job) 

Also, ground trace should not daisy chain from one component to the next, especially if one of the components on there is a crystal. Noise from internal switching on the microcontroller will get introduced to your ground all over that trace and will raise the 'potential', basically you won't have a true ground to reference anymore. Also, it's one long electromagnetic antenna, picking up radio frequencies. This could potentially effect your timing.

If you were to redesign, I would recommend either learning about polygon ground pours or, at the very least, draw one huge fat ground trace up the middle of your board and have all components that need to reference off it connect straight to that, not each other." 

I have not yet made the second version with the improvement so i cannot comment on that but i will post as soon as  i do. [UPDATE: i did a little resoldering and changed the crystal and capacitors just to make sure and it is working much better now , no hicups so far ]Now ignoring that little issue lets get into other ways it can be improved.
You can see i bent the voltage regulator back to lower the over all profile of the board. 

However the towering capacitors are not as friendly when it comes to bending. 

The best fix for this is SMT!! surface mount technology. I could get some surface mount electrolytic capacitors like the ones on the Arduino 

I could also get the surface mount voltage regulator most similar to the Arduinos MC33269D-5.0

The only issue with all these SM components is that if you have not noticed my soldering is far from pretty and that is using regular components , now imagine trying to solder smd's (surface mount devices) .

Another thing my clone could use is a way to bootload it with out having to remove the chip. This is simple

All i would need are 6 male header pins or a little ISP box which is basically 6 pins in 2 rows of 3 

To go about  the actual programming i could use my USBTINYISP i got from ebay for about 11 bucks here
which i do recommend anyone getting it because a pre loaded chip with arduino firmware is about 2 bucks more, so after a couple of projects you'll save your self a lot of money. specially if you buy chips in bulk. 

plug this baby to the 6 pins i theoretically added  on my board and use the Arduino Ide to bootload the chip

Tools >> Burn Boot Loader >> w / USBTINYISP 

The question is what do I wire the 6 pins on my board to? 

Simple.. Look at this picture of the 6 pins and it shows where on the 328 they go wired to
NOTE: the number on the 6 pins does not mean it goes to pin 1 or 2 or 3 ... of the 328 thats just the number of those pins .... for example Pin 1 on the ISP pins go to PROG_MISO which is pin 18 on the chip. 

Pretty straight forward. I have yet to actually do this but i will post as soon as i do. I have to order some blank chips, being broke and unemployed does not speed the process either :( 

Furthermore I could add a usb to serial interface , I do not know the actual process and components involved in doing so but I do own the module from sparkfun for 15 bucks 

Now this little thing i simply Connect its TX to My boards RX and its RX to my boards TX pins and add ground and 5v and it  shows up on my computer  as a COM port  and  i can upload sketches through it with my Arduino ide. But at 15 bucks it kind of defeats the purpose of making your own Arduinos because this piece alone racks up the price, so I can do with out it and just pop the chips out to upload a sketch or simply add the female headers to my board and wire this baby to it and simple as that, but i would not permanently mount this to anything since its 15 dollars. 

To further develop my board i printed my  circuit board. But I will use a new post for that since it is a process in it self, and very easy might I add. Publish Post

Genesis...

I tried to think of, for about 2 minutes,  some nice formal or perhaps funny way to introduce my self or start this post off but nothing came. That being said lets do this!

I believe to fully understand the Arduino, we must first look at its architecture and mimic it. 

Most things we learn we learn by copying at first , do not take my word for it but it sounds about right. 

In all my post if i am using any specific part i will give a link to where I got it from as well as part number and price, just because I love it when other people do that and find it helpful.

Parts From Jameco.com

28 Pin Socket : this is where you will insert your Atmega Chip, or you could permanently mount the pin but for

convinence purposes i sugest buying a socket that way you can remove the chip and adjust your code whenever you please.  ( part number : 683171)

$0.25

This tactical momentary button will be our reset button, self explanatory there,but is it necessary? YES! right now i will not explain why but later i shall. 

(part number: 162886) $0.35

This is a very popular voltage regulator, basically when you power up your arduino with a 9 volt battery or any power source between 6 volts and 12volts this baby drops it down to 5v so you do not have your Arduino resembling a chimney. this is called a 7805 all the cool kids are using it. (part number: 51263)

$0.35

This is a 10 micro farad capacitor, for everything ive posted so far you only need one of each but you will need two of these, dont worry they only cost 6 cents . Basically this babies are to smooth the flow of  voltage or current ? Because what if you have a power source that bounces between 6 volts and 7 volts, this baby will make it spit out a nice smooth flow. (part number : 29891) $0.06 need 2!

This is the same as above, a capacitor, except this is a ceramic type, and its value is 22 peco farads. these will go from our crystal to ground. whats a crystal?

(part number : 15405) $0.06 also need 2!!!!

This is a crystal, its that shiny silver thing on your Arduino, it runs at 16mhz and this is basically how arduino keeps time, how else is it going to know what delay(1000) is... (part number : 325139) $0.59

same as the other capacitors except its value is 0.1 micro farads (uf) , now this i did not use on my Arduino Clones but i found out today it is important. I will not show it on my build because i didnt use it but i will tell you where it goes. everything will function fine without it thought so no worries (part number : 544921) $0.14

you could also buy some female break away headers or just wire the pins you need

http://www.robotshop.com/break-away-female-headers.html?utm_source=google&utm_medium=base&utm_campaign=jos

Now  I ordered all these parts from Jameco.com in parts of 10 and some parts only  5 and still only spent 11 dollars :) how cool is that. Make 5 arduinos for 11 dollars.  the only thing you still need which i will not give part numbers and price is because you can find this localy at Radioshack so paying shipping for it is not worth it. That includes your sodder, wires, at least 3 different colors to keep track of things. and prototyping/perf board 

OK now here is one very useful image that I suggest you save .

This will help us figure out what goes connect where. 

As far as getting the Atmega chips, thats the most expensive part which a bootloaded chip will run you about $4-$5. You can also get blank ones foe about 3 bucks and we can then dive into how to bootload those. But for this blog post let say you buy a pre bootloaded chip or just use the one on Your Arduino. Do a Google search for  "atmega 328p-pu" and then click on shopping and take your pick. 

I also assume you have resistors but if you dont , we will use one 10k ohm and one 220 ohm.

I know my intro says this is not mean to be a guide but sure does sound like one.

Now here are some pictures of what your finished product will look like. To the left I have an Arduino clone, which is being used by a Tv-Bgone clone , on a proto board.  On the right i have another Arduino Clone but this time on a printed circuit board I made.

Now the difference is better seen when you look at the back. 

You see how messy the one on  the left looks compared to the right, its because on the perf board there are no "traces" so i had to use a wire to connect everything. But for now this is fine we just want to make a working Arduino no matter how pretty it looks. 

Ok I will try my best to show this even though i am not in the process of building one right now and do not feel like it either. 

so here we go! 

first start by placing the socket in a convenient place, preferable with more available space on the left then the right since more components will go to the left of it. I will not post soldering picture because i assume you know you have to solder the piece on, and like i said i am not actually building one right now the pictures are just for reference. i will however suggest you just solder only the 4 corner pins It will make things easier to add the rest of the components. also the way you will be placing the Atmega chip is in a way that the upper left pin socket is where pin 1 of the chip will be. 

Now if you go look at the diagram of the 328 (Atmega328p)  you will see that the crystal goes connected to pins 9 and 10. It does not matter which lead goes to which pin , crystals are not diodes so there are no negative or positive ends.  Place the crystal some where near where the 9 and 10 pins on the socket are so our connections do not have to stretch across the whole board.  along with this step you will also connect one end of the 22pf capacitors to the crystal.. So the connection goes something like... pin 9 to one end of the crystal and on that same end of the crystal one end of the 22pf capacitor. Then do the same thing but on pin ten.Then the other end of the capacitors both will go to ground.Note: just because the 2 ends of the capacitors both go to ground do not connect them together, that is called a daisy chain and its not a good idea. when we add a power supply we will connect them individually to ground. , for now leave them like that.

Now Add the voltage regulator and a capacitor before and after it. The capacitor has to be connected properly, the negative side (short lead/ or side with the stripe) has to go to the ground of the regulator. 

both capacitors negative side will go to the ground, however the one behind it will connect its positive side to the regulators input and the capacitor infront of the regulator will connect its positive to the output of the regulator. We will add Power over 5volts to the capacitor behind the regulator and it will smooth the voltage entering the regulator, then the regulator will drop the voltage to a steady 5volts, and then the capacitor in front of the regulator will further smooth the 5volts being outputted . from this capacitor is where we will wire the power to the chip and a power LED, which i forgot to mention on the parts list, sorry. I actually grabbed all the LEDs from our christmas lights. 

Now add a button somewhere  above the socket as well as an LED i wont show a picture because this is basic, do not solder them yet just put them on there for reference. the the 220 ohm resistor will be for the LED and the 10kohm resistor will be for the button. Lets talk about that Now.

Note: to make the following connections you can just use wire from one lead to the pins  or if the component is close enough to reach just make sure nothing touches. What i did was just use wire and only strip the very tips so that when wires overlap they copper is not actually touching.

In order for the Arduino  to reset you have to take Pin 1 and give it ground. but if we give it ground then it will always be resetting  and we obviously do not want that so we have to connect that pin to a positive voltage with a very low current, hence the 10k resistor , so you will have a 10k resistor to pin 1 , then the  other end of the resistor to positive 5v coming out of the capacitor INFRONT of the regulator.

 Also to pin 1 we will connect the button because we also need to be able to reset at our will. So connect one pin of the button to ground and another pin to  pin 1 on the 328,

when i say 328 i actualy mean the socket but this is where the chip will go so its the same thing. And when i say ground it also means ground of the capacitor INFRONT of the regulator. Also remember with those buttons with 4 leads , pin 1 is always connected to pin 2 and pin 3 is always connected to pin 4, so you have to connect pin 1 to pin 3 or pin 2 to pin 4 , the only time those 2 pairs are connected is when you press the button and thats when we will send the ground signal to pin 1 of the chip to reset it.  you can play around with an led to find out which pins are which. 

Also looking at the Above Picture pin 7 and 8 are Power to the chip and ground respectively. So you connect 5 volts coming out of the capacitor INFRONT of the regulator to the vcc pin 7 and Pin 8 gets grounded with the ground / negative of that same capacitor. when i say power and ground from now on i am referring to the capacitor INFRONT of the regulator i just dont want to keep repeating my self. 

If you look once again at the picture pins 21 and 20 also go to 5v and pin 22 goes to ground. 

Also remember the end of the capacitors leaving the crystal go to ground. 

As far as the power led goes just connect the anode to positive 5v and the 220 ohm to the cathode and the other end of the resistor to ground. 

Okay one usefull tip so you dont have an ugly mess of wires is to grab some wire and  strip it completely and connect it to ground and run that wire down one side of the board, so that when you have to connect something to ground you just connect it to that wire , instead of 50 wires all trying to connect to the capacitor. same goes for the positive side 5volts side.  I didnt do that so i have no picture to show. 

Now to make this usefull you can add female headers so your clone resembles the functionality of an Arduino. 

wire the headers to the corresponding pins , in the picture it tells you which Atmega pin does what in the Arduino, for example if i wanted to use my analog pins i could add some headers to the top right near the socket and wire each of those to each pin on the socket and i can use those analog pins. You can add headers for all the pins or just what you need for a certain project that is up to you. 

To add power to this baby add 2 female headers,  like the ones shown above, behind the the capacitor that is BEHIND the regulator wire one header to the positive and one to the negative and this where your power supply will be plugged in. to get a steady 5v out of the regulator you should supply over 5volts . i am too lazy to research the ratings on the 7805 right now to tell you the max volt it can handle but im sure you can find that out.  Also do not forget to add female headers connected to , because most sensors and other things need ground so you have somewhere to plug their grounds. the arduino only has about 3 so if you need to ground something else you need to start using your digital pins and setting them low , but if you add ground pins then it helps save those digital pins for other things. 

And if you want a "5v" pin just like the arduino then add a female header and wire it to 5v from the front capacitor and if you want a "Vin" pin like the Arduino add a female header and wire it to the positive side of the capacitor BEHIND the regulator.

Now all you have to do is add the 328 and connect your sensors etc... remember the atmega chips has to be oriented right, on the top of the chip there is a little notch shaped like a "U" that is the top and that goes to the side where the button is. 

and that is about it, if I have forgotten something please let me know since i am not building one as i type i could of forgotten something. Also let me know if you have any questions. 

My next post will be on further developing this and ill dive into the boot loading process if you have blank chips. You can also build this on a breadBoard. the tutorial is found  Here