Step 1: Section 1 - Building the Regulated 5 Volt Power Supply !

Okay now before i start, something about my notes for my step-by-step PICTURE instructables that i Love to create:

"i used to label all my pictures within my instructables but it seems instructables.com doesn't show all the notes attached onto pictures with certain web-browsers so i will be only making a few notes Directly onto the Pictures but have the main instructions here in this typed section but for those of you that dont see any notes on the pictures either download and install another web-browser (i Use Opera and have Never had a Problem Seeing Notes on Pictures!) or just look at the notes in this typed-section of the Instructable Guide i have made !!

Observe the pictures carefully and take special note on the exact holes that the wire links & components go into, failure to follow the exact holes will result in this not working, i have painstakingly taken the highest resolution pictures as i could so there shouldn't be any problem viewing the pictures and if a component or wire link is being blocked by another component then i will have supplied a few pictures taken at different angles to show exactly where the placements of the components or wire links should be (this is something that wasnt on ANY of the websites i researched, darn it! lol) so look out for the different angles of pictures as they will be following each other, in organised fashion (im using different angled pictures so that anyone will be able to CLEARLY SEE what goes where!)

"ALSO i do explain every step in DETAIL so if you dont want to read too much just skip the reading and follow the picture instructions but i have included alot of info here - gathered from a great many different websites so reading this guide once fully wouldn't hurt but if you know what your doing please dont see this guide as an insult to your intelligence as ive put this together so that complete beginners like myself can easily follow these instructions !"

  • Now, start by chopping up some single-core wire into the different lengths (or just chop them as-you-go!) so that your breadboard adventure for this project will go a little quicker and i have included a few pictures with a ruler to show all the wire links i used so you can roughly see what kind of lengths are needed but i dont get my wire links perfect 1st-time and it takes a few tries to get the right length but this is a good thing because it just means that with the colours of the wire links youve made whilst making them for this project means you can use them in many other projects as well in the future so it wont be a waste to try a few times to make the wire links!

After you have your wire links, its time to start !

The Power Supply:

NOTE: its VERY-Good practice to leave the 'Power' colours of the wire links as BLACK for the Negative (-) and RED for Positive (+) as it just makes life Soooooooo-Much easier later on to clearly & easily see which sections of the breadboard are specific to Power (Either battery or mains power!) !!!

Also i used a bit of Green Single-Core wire  & its not in the first 3 pictures but you will easily spot it when its used (For the Tactile MicroSwitch!)

The Bottom-LEFT picture (Picture 1) is showing that you cut your wire lengths a little bit longer on both ends so that when you strip them you'll have enough bare wire to slot into the breadboard holes, The Bottom-MIDDLE picture (Picture 2) will show what im barking on about, lol, & the Bottom-RIGHT picture (Picture 3) is simply showing how to have the bends in the pieces of wire!

Now we finally start the Power Supply, lol !

NOTE: ALWAYS COPY THE RED & BLACK WIRE-COLOURS EXACTLY - You may Use any other colours for the rest or the wire-links as you please!

Start by looking at the picture below (Picture 4), and copy the wires exactly - NOTE: the Blue-Negative-Power-Line on the breadboard is at the TOP.

Here You have a Choice of Either Using: 
  • The SMALL Low-Power {300mA} TO-92 Type 5v Voltage Regulator or
  • Another SMALL Low Power {300mA} TO-92 Type 3.3v Voltage Regulator
  • The Bigger TO-220 Type {1Amp to 1.5Amp} 5v Voltage Regulator.

Voltage Regulators Used - Please Look At their DATASHEETS to make sure you get the pins in the right holes for connecting !!

L7805CV - 5v @ 1.5 Amps (1500mA)

KIA78L05 - 5v @ 0.15A (150mA) - This is NOW DISCONTINUED,
Download Replacement 5v Low Power Datasheet below:

MCP1702-5002E - This is Now being used for all the Battery-Powered Kits, 5v @ 250mA

L4931CZ33-AP - 3.3v @ 0.25A (250mA) This is for special 3.3v Kits, carefully check the Datasheet so you know which pins are INPUT, GND & OUTPUT !

You will need: Both 47uF Electrolytic Capacitors & The 5v Voltage Regulator  {Im showing the insertion of the Low-Power Voltage Regulator first (The KIA78L05) and this one is the SMALL TO-92 Type} Shown below (Picture 5), CAREFULLY Observe the Capacitor Legs going into the correct holes, the SHORTER LEG is the MINUS (-) and must slot into the NEGATIVE ( - ) Power Rail on the breadboard ! As for the 5v Regulator make sure the ROUNDED part is facing you and the flat side is NOT facing you, as shown by the Picture's View from above ! The picture Below_RIGHT (Picture 6) is showing the above installed parts from an angle to better see which holes the legs have been inserted into...

Looking at the Voltage Regulator in the above two pictures, from LEFT to Right the PIN-Labels are:


                   INPUT Voltage   >   GROUND   >   OUTPUT Voltage
                     (RED Wire)         (BLACK Wire)         (RED Wire)

Now i will show you how i use the BIGGER TO-220 Type Voltage Regulators with breadboards without damaging the holes and causing intermittent connection problems that these bigger type Regulators cause within the holes as their LEGS are very thick and not designed for breadboard prototyping so to prevent enlarging your breadboard holes this is what i do:

The 1st Thing i do is solder some short pieces of single-core wire onto the legs of the TO-220 Type Voltage Regulators (Assuming that you will always use this Voltage Regulator for prototyping purposes only and not be soldered into a permanent Arduino Project so its always Dab-Handy to have a few of these in your inventory of components!) and after soldering i use heat-shrink to cover up all the exposed bare-metal and wires that i do not want creating short-circuits when using these in my breadboards...

The pictures Below are showing the process of soldering the wires to the legs of the Voltage Regulators and i use RED wires for the INPUT and OUTPUT leg and BLACK Wire for the GROUND leg:

If you do this as well then you wont ever have the problem of having 'Enlarged Holes' in your breadboards and it will save you time and effort taking apart your breadboard to affect-repairs! Also as i had a few things to solder i usually keep a box specially for things that need soldering and wait until either i need them soldered or when there are more than 5 different items needing to be soldered so im not continuously getting my soldering kit out like a Yo-yo, lol

On with the instructable! lol

Next, bend ONLY ONE of the 0.1uF (100nF) Capacitors as shown in the small picture Below-LEFT (Picture 7) and insert it any way you like into the holes shown in the 2nd picture Below-RIGHT (Picture 8) but..... When a component can be inserted any way i always prefer to have the side that has the writing-on showing & facing me, thats only due to personal preference, its completely upto you !

Grab the 1N4004 Diode and bend it just like shown in the small picture Below (Picture 9) but Pay SPECIAL Attention to the Grey STRIPE and what side its on !!! This is added for Reverse Polarity Protection! Also grab one 1K Resistor (Colours: Brown,Black,Red,GOLD) and bend it like shown in the 2nd small picture Below (Picture 10), and Grab the GREEN LED and Closely Observe it has a FLAT-NOTCH on one side of it as shown in the 3rd small picture Below (Picture 11), This is the Cathode Side or MINUS ( - ) Side (NEGATIVE) and the LONGER Leg is the Anode PLUS ( + ) side , bend this as shown in the 4th small picture Below (Picture 12)... (Now if you want to keep the Parts-Count as Low as Possible you can choose NOT to use the LED or 1K Resistor in this step)

Once These 3 components have been prepared,insert as shown Below: (Picture 13)

Picture 14 is showing the newly completed section which is shown just after the heading, The Power Supply above!

DONE !!! - Take a little break as you've just Completed The Power-Supply Section of This Guide !! But Wait !!!!

Before Proceeding ANY FURTHER You must test this section and make sure it works before continuing and BEFORE ADDING anymore components just in case a mistake was made, and if a mistake was made it would be better to correct it here and now with no harm coming to the precious ATMEGA328P-PU  Microcontroller as its not been installed yet, after-all when you've installed the ATMEGA chip you really dont want to blow it up by putting too much voltage through it do you ??? No. Didnt think so, lol !

Remember this Microcontroller Has a MAX Voltage INPUT of only 5.5 VOLTS (a range from 1.8v to 5.5v ONLY) so when your using a Voltage Regulator you'd be using anything from a 9 Volt to a 12 Volts for the INPUT Power Supply whether it be from the mains or a battery Pack and THIS would INSTANTLY KILL the Precious ATMEGA328P-PU  Microcontroller that has the Arduino UNO Bootloader Loaded onto it leaving your Breduino Without a functioning Brain ! So...

Grab your trusty DMM (Digital Multi Meter) and test the GROUND and OUTPUT LEG of the voltage regulator to make sure it is indeed producing upto the 5v that we need ! You will need to connect up either a battery pack or a mains adapter (aka Wall-Wart, lol) to your breadboard Power BUT NOT AS YOU NORMALLY WOULD - Observe the Picture Below (Picture 15) and Notice WHERE PLUS ( + ) {RED WIRE} is being plugged into !! - NOT the red power line of the breadboard !!!

As you can See on the Picture Below (Picture 16) i am using a battery pack comprised of 8 rechargeable Energizer Batteries (1.35 Volts per Battery Fully Charged, approx, so 10.8 Volts Battery Pack being used - well within a recommended tolerance for the Voltage Regulator so that it does NOT lose alot of efficiency due to being overheated because if a higher voltage is being pumped in, the more-voltage being fed to these things - the less efficient they get but not to say they dont do thier job correctly of supplying 5 volts, no no no, its just that they would waste energy in the form of HEAT, Higher Voltage = More Heat produced by these things = power wasted as heat and a quicker drain on a battery pack !)

Also You can see in the Picture Below (Picture 17) that ive added a SPST Slide Switch to my Battery Pack because i like to insert the cables into my breadboards and have it not supply ANY Power to my components until i've Tripple-Checked Everything ive done so far because...

i have been told by the most well-knowledgeable of Electronics Experts that have PHD's and over 20 YEARS worth of education & Experience in Electronics that they also sometimes Get Simple things wrong by not taking the proper precautions and Double-Checking & Even TRIPLE CHECKING their work before Powering Up any Circuits so thats why the switch is on all my battery packs so i can connect it all up & check all my connections like:
  • MAKE SURE that the Electrolytic Capacitors Polarity IS Correct ?
  • MAKE SURE that the 1N4004 Protection Diode's Stripe IS Correct ?
  • MAKE SURE that the LED Cathode ( - ) IS Correctly Placed in the ( - ) IS Correctly Placed in the ( - ) Breadboard power Rail ?
  • MAKE SURE that the Voltage Regulator IS Sitting Correctly ?
And if the answers to those component checks is YES YES YES YES , then i flip the switch on my battery-pack and.... YAY !!! Check out the Picture Below (Picture 18) To see the GREEN LED come to life and tell you that the 1st Section of this Guide is complete !

Okay so a fellow instructables member, abqlewis, gently reminded me that in my magnitude of explanations and thoroughness that i had forgot to add a wire link that connects the top positive power rail of the breadboard with the lower positive rail of the breadboard, without this wire any current would travel through the microcontroller to get to any components that you would hook upto the Atmega Pins but with this wire link in place any components would get their power from the shared power from the rails on the breadboard and not rely on getting the power from through the microcontroller, this would have been fine for light to medium projects like LED projects and low power projects but anything heavy-duty would have put a strain on the chip...

 Below, the Left picture below is where this page of the instructable finished and the picture on the right is the Red Positive wire link in place to connect both the top and bottom power rails (Many thanks for the catch abqlewis !!!)

Now you can take a quick break

                               Carry on into:                                                                    Or
Section 2 - The ATMEGA328P-PU  Microcontroller !                            Go Back To Intro

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