Arduino Library Import & Errors

After hours of searching on Internet without success I finally find out how to import library in Arduino IDE to work properly. I will write it down so you don't need to lose couple of hours on search without results.

Firstly, internet is full of advice and ways how to import library in Arduino but for me none of these doesn't work.

After I tried import library in the way to copy downloaded library into Arduino libraries as internet says. I got errors like this:
multiple definition of `LiquidCrystal_I2C::pulseEnable(unsigned char)'
LiquidCrystal_I2C.cpp.o: In function `LiquidCrystal_I2C::send(unsigned char, unsigned char)':

What I figured out is that the way I "import" library is totally wrong.
The way I solved it is below!

1. Download library (.zip file)
2. Open Arduino IDE 
3. Go to Sketch --> Import Library --> Add library...
4. Select your .zip file of Library --> Open
5. Now your library is Imported correctly --> Everything works, no errors!

NOTE:
Do not UNZIP Downloaded Library.



If you work with Arduino NANO and Arduino UNO the most common Error is below:
avrdude stk500_getsync() not in sync resp=0x00

To fix this ERROR Only thing you have to do is:

1. Open Arduino IDE
2. Go to Tools --> Board
3. Select appropriate Arduino 
4. That's it! Enjoy!

Read More

How to make Positive and Negative voltage

One of the most common question when it's about amplifiers is how to make +/- voltage needed for IC-s  for instance (TDA7294 or even amplifiers with complementary transistor). btw it's not like when you connect battery in opposite direction to voltmeter and it shows negative voltage!! There are two ways how to make Negative voltage. 

 * First and the easiest way is to use two the same DC power supplies. 

 How to connect it?

1. Connect positive(+/RED) terminal from 1st power supply to negative (-/BLACK) terminal on the second one. That will be your common terminal, ground, point whatever.
2. You are done, but you don't know it yet. Now you have common point and if you connect your  voltmeter(-) to common point and with (+) side of voltmeter to BLACK terminal it will show negative voltage while on the RED terminal will be positive voltage. That's it, instead of voltmeter you connect you own load or voltage stabilizer.

 *Here is the second way to make negative voltage, it's a bit complicated but not too much. If you understand basics of transformers and rectification then it's no big deal. ;)

 Parts you need:

• 1 - Transformer with 2 secondary
• 1 - Bridge rectifier or 4 diodes
• 2 - Capacitor usually 2200uF

Normal transformer with one secondary has 2 wire on primary(which goes to wall AC) and 2 wire on secondary(AC) while transformer with 2 secondary has 2 wire on primary and 4 wire on secondary. That's basic difference.

Now you have 4 wire on secondary. You have to connect 2 wire together but not from the same secondary it has to be one wire from first connected to one wire from second secondary and that will be your COMMON POINT. If you connect 2 wire from the same secondary you will make short circuit which can destroy transformer. So be aware what you doing.

With that COMMON POINT you have 2 more wires. These 2 wires have AC voltage you assume that we need DC voltage so we have to rectify it. You take these 2 separated wires and connect to bridge rectifier to get DC voltage. With 2 capacitors fix dumps in voltage and you are done. It will be more clear when you take a look at picture below.

I hope that negative voltage become more clearly now :) enjoy!
Like, comment, subscribe :)

Read More

LM7905, LM7906, LM7908, LM7909, LM7910, LM7912, LM7915

As 78XX version, 79XX is also voltage stabilizer. But like 7805 have +5V stable the same is with 7905 just with opposite (negative) sign or -5V that's the only difference between these two voltage stabilizer. And here also the last two digit of 79XX represents negative output voltage. More detail about power consumption you can look at my previous post about LM78XX it's the same calculation.

ATTENTION

I know a lot of people who asked me if they can normally connect +12V on LM7905 as on LM7805 and the output voltage would be NEGATIVE -5V. Answer is NO!!!! Don't even try it otherwise your IC is DEAD! It would be remarkable to connect +12V and then he convert to negative voltage. But the man who would invent that hasn't been born yet. :D  If you want stabilized negative voltage you must have negative input voltage. Now transformers with two or more secondary coil come to expression. but that in the next episode :)



They can be found in different package as well as LM78XX, that's standard type TO-220, TO-3, SOT ... more about it you can find in datasheet.



How it looks in schematic

LM79XX DATASHEET

Read More

Power supply [1.2 - 25V, LM317]

After a quite a while, finally, I'm coming with new project.  It's about simple power supply which anyone can make at home for really cheap price ($10) without transformer. It gives max 25V with 2A. Why can't give more than 2A? It's because LM317 can max handle 2A (TO-220 package), but i predicted that maybe it won't be enough so i made PCB board which can handle at least 5-8A of course without LM317. If i want more power, with output of 5A i can easily remove LM317 and replace 2N3055 (TO3 package) but then you need bigger cooler, but everything will working perfect. Also LM317 can handle up to 37V. That's not everything i assumed, also there is Volt,Amp meter integrated on board and stable +5V (LM7805) I'll show it below

Parts:

• 2 - Electrolytic capacitor - 2200uF/35V
• 4 - Block capacitor - 100nF
• 2 - Bridge rectifier - 2W10
• 1 - Green LED
• 1 - LM317
• 1 - LM7805
• 1 - Resistor - 1k5
• 1 - Potentiometer -10k
• 1 - Resistor - 460Ohm
• 4 - Terminal connector -1x2 (you can use them or you can solder wire direct to PCB)
• 2 - Header - 1x2 (Amp, Voltmeter again you can use them but you don't have to, It's up to you)

 What you MUST consider before you make it

First some general knowledge, when you connect 120AC[US] or 230AC[EU] to appropriate transformer you will get 12, 15, 18, 24AC etc. on secondary,  it's variable, depends of transformer. When you finish the rectification (AC to DC) you don't have 12, 15, 18, 24DC anymore. Actually you have the nominal secondary voltage multiplied with square root of 2. So it looks like 12*√2=17V,  15*√2=21V, 18*√2=25V, 24*√2=34V. Therefore you have to be aware of this, example: if you want 12V power supply and you have transformer with 12V AC on secondary, let's say you put 1000uF/16V Capacitor but your DC is 17V so when you connect this to city network, your capacitor is dead.

Second, YOU MUST BE CAREFUL when you working with 120AC or 230AC it can kill you instantly.




Schematic

Power supply schematic

Power supply PCB

PCB 3D TOP

PCB 3D BOTTOM

You can find and download ALTIUM DESIGNER file (PCB, Schematic) on the link below.

DOWNLOAD HERE

I hope you like it :) Thanks

Read More