This project is based on great Scott's project from instructables. My basic difference is that I use an arduino mini clone which costs 2-3 $ while Scott uses an Atmega chip individually with the components required (crystal,capacitors,voltage regulator). I found it more easy and compact to use the clone. The whole trick is to send an amount of current to the resistors so they can burn, this command will be sent with our mobile phone, while the bluetooth module will receive and will energise the right transistor. Scott also had a voltage comparator which is being connected to analog pin 0 (A0) so that if the program see we have less than 5v and it will stop. Make sure to have the bluetooth module disconnected when you upload the program to arduino, also by reprogramming the app you can add more outputs, so more explosives can be connected!
The code and the app can be found here : https://www.dropbox.com/sh/3ygdquejq10xg42/AACNF-hc46Oghhfn9L9Sq-gQa?dl=0
If you want you can visit : http://appinventor.mit.edu/explore/
and modify the app so that more fireworks can be connected!
Last November I went to Beograd with a friend of mine and we couldn't resist visiting Nicolas Tesla museum. There is a room with his famous Tesla coil which produces thousands of volt, the guide there tell the people to take some fluorine bulbs and when he turns on the switch, magic happens, and the bulbs turn on wirelessly, with no connections at all! The trick is at that voltage the electromagnetic force is very big and makes the fluorine to glow. I searched the web for a simple tesla coil and most of them are similar with different NPN transistor but still we have the same results. The connections are pretty similar but the basic rule is : Vs = Vp (Np/Ns)
*Vs = Voltage Of Secondary Coil
*Vp = Voltage Of Primary Coil
*Np = Number Of Turns Of Primary Coil
*Ns = Number Of Turns Of Secondary Coil
In my Experiment I use a 12v Battery and Np is 400 turns while Ns = 2-3 turns, So you can make the calculations and see the final Voltage. For the coil I used a plastic pipe of 28 cm length and 2,5 cm diameter. The wire is magnet wire especially for coils and it's thickness is 0,40 mm. At the end I used a tennis ball warped with aluminium foil so I can make the capacitance even greater, of course we have to connect it to the end of the primary coil.
The schematic is from "electroBoom" check out his youtube channel this guy is great! In my occasion R was 10k but I started with 22k, Q = is NPN transistor TIP 31C and D are 2 general diodes IN4007.
If everything is ok turn on the circuit and then place next to the coil a fluorinated lamp and wait for 2-3 seconds. If nothing happens check your connections, most people connect the secondary coil backwards, so here is the most frequent problem. You can connect a heatsink to your transistor, reduce the value of R or increase the turns of the primary coil if you want to make your circuit even stronger. ALWAYS check the heat of your transistor,a big amount of current will make the magic smoke appear so be careful!
And bonus a picture from the museum of Nicola Tesla in Beograd
Maybe the hardest project I made so far. Based on the idea of embedded lab, I wanted to make it from the first time I saw it (http://embedded-lab.com/blog/?p=9255). There were two problem though! First of all the code works perfect but the hardware part had some errors and these errors gave me a bad headache. I don't think it was his intention to have errors but it took me lot of time to find them and gave me a chance to see how 8x8 works (well the hardware part I still luck in experience in the programming part :) ) Second problem was that jollifactory maybe a similar project with bi-color matrices (http://www.instructables.com/id/7-Bi-color-LED-Matrix-Scrolling-Text-Display/) and I like it a lot also. So I started building the second project, finished all the hardware parts and transfered the code to arduino but it didn't work as I wanted, after a lot of search, study and "trial & error" the answer to my problem came, it was the programming part, nick from jollifactory (who is a wonderful guy and helped me a lot with my questions) had made the code only to work with bi-color matrixes and it needed major modification if I wanted to work only with red matrixes. So I went back to the first project of embedded labs. 3 problems I encountered and it took a lot of time especially "waiting time" since the first 8 matrixes were common anode as he suggests but the project works with common cathode matrixes!!!
So let's start, these matrixes are 8x8 5mm and common cathodes this mean they have the code letter (A) and you can find the difference from common anode because common anode have the code letter (B), so in my project I ordered 8 pieces of 2088(B)S (common anode) but the project needed 8 pieces of 2088(A)S (common cathode).
Matrixes come in various sizes but I wanted as bigger it could be and 5mm is the ideal one, the problem here is that the boards with the chip max7219 (driver chip) come with the premise we will use 3mm matrixes, so I had to figure a trick to connect the 5mm matrixes with the small boards...
After these modifications we chain our 8 matrixes together meaning that the Dout signal of the first goes to the Din of the second, the Dout of the second goes to the Din of the third e.g. till the last one.we also connect CLK,CS,V++, GND together. V++ is 5V and GND is the ground. now we have 3 more pins. CLK which is the clock connects to pin 13 of arduino, Din of the first module connects to pin 11 of arduino and DS (or LOAD) connects to pin10 of arduino. A useful idea would be to connect 3 resistors of 10k from pins 10,11,13 of arduino to ground, with this trick our matrix won't get "garbage" from outside. Also we can connect a resistor of 1K between pins RX and D2 of arduino, this will be a hardware delay for out marix, so it can forestall our bytes when thay re being sent by our phone. Finally it's the bluetooth module which is being connected to 5V,GND, Rx of bluetooth connects through a voltage divider to pin Tx of arduino, and Tx of bluetooth connects to Rx of arduino. Upload the code and you are set to go. The app we use is Bluetooth SPP tools pro. The config of the program is easy and with 10' of searching you will be able to understand how the program works.
commands :
(message) the scrolling display must be sent inside a parenthesis
/p to pause the scroll. Sending it again will resume the scroll
Don't forget to visit this site for extra informations of this incredible project !
(message)
– The scrolling display message must be sent enclosed by parenthesis. -
See more at: http://embedded-lab.com/blog/?p=9255#sthash.yRMeEzfv.dpuf
(message) – The scrolling display message must be sent enclosed by parenthesis.
/p to pause the scroll. Sending it again resumes the scroll.
/< to scroll faster
/> to scroll slower
/+ to increase brightness level
/- to decrease brightness level
/e to erase the display
- See more at: http://embedded-lab.com/blog/?p=9255#sthash.yRMeEzfv.dpuf
(message) – The scrolling display message must be sent enclosed by parenthesis.
/p to pause the scroll. Sending it again resumes the scroll.
/< to scroll faster
/> to scroll slower
/+ to increase brightness level
/- to decrease brightness level
/e to erase the display
- See more at: http://embedded-lab.com/blog/?p=9255#sthash.yRMeEzfv.dpuf
This project is the brain of the future house, you can control your home through internet from another place of the world and just an ethernet shield connected to the arduino board, you can control your home through wi-fi with another module, with this circuit I show you, you can control your appliances through bluetooth with your android phone. Based on the project of these Thai guys "http://androidcontrol.blogspot.ie/2014/06/android-bluetooth-control-8-devices.html" and the android app here: " https://play.google.com/store/apps/details?id=com.app.control", now our life can be a lot easier since we can turn on a switch which controls a lamp or the water heater from our bed! The project is based on an arduino, which depending the data it takes from the bluetooth module controls 8 digital pins-outputs which are controlling 8 relays-switches. In my occasion the specs of the relays were : 5V coil, switch 230V. Meaning that the relay could be armed with 5v and can control a load till 230V. The module I got had also 8 LEDs which show when the relay was armed, and also 8 npn transistors and 8 optocouplers which controlled the relay for better protection.
The schematic is very easy to follow and with the arduino code the Thai guys provided, this project can be made in an evening, now depending on your demands you can use it as you like. The video here is very informative and it shows how the program works, it also has 8 independent timers which can be set for different timings. Every time I pressed an output on my phone, a relay was energized and an Led was light on. If I pressed again the same output the relay was de-energized and the Led was light off. Finally I also provide 2 types of code one with active low, meaning all ouputs are off and when you press your phone they go high, and one code active-high meaning all outputs are high, and when you press your phone they go low, I suggest to use the active-low code. Arduino Code : https://www.dropbox.com/sh/ceqntenyh8jbwy4/AABw_n1hyKHJG9HRrZmw4H44a?dl=0
A few days ago a friend of mine gave me a fault power supply, which he was going to through away. I tooked it from him and I repaired it. In most cases of a pc power supply the problem may be occured due to false capacitors which are the first parts to show some damage in a period of time. One big advantage if a capacitor is false it's that you can see it immediatelly (mostly!) without a special meter, because a blown capacitor looks different from a good capacitor. Precautions must be taken in case a capacitor still is charged because you might have a good zap! Measuring the voltage across their legs and discharching through a 5W - 1KΩ resistor is a good solution. Opening the case I was lucky to find quickly the two bad components. Unfortunatelly I didn't took a picture from them when they were on board but afterwards.
The capacitors where positioned in the corner left, as you can see from the pictures the difference between 2 fault capacitors and 2 good capacitors are visually easy. Pay attention to capacitance ratings and voltage ratings, The ones you change should be same capacitance and if not same voltage, then bigger. If they are bigger voltage pay attention because the size of capacitors increases too and it will need some extra effort putting it back to the board. Next step is to download a schematic with all the wires and their names (voltages) connected to the 24-pin clip or 20-pin clip. (In my ocassion 24-pin).
As we can see there is a pin named "PS_ON#" (in most cases it's green) and this one should be connected to ground if we want to power on our supply without connecting it to a load (e.g. the pc).
Next step is to measure all the voltages according to the above schematic, so these are the values we should take from every pin. : +3.3 Volts, +5 Volts, +12 Volts, -12 Volts. Colors of cables should be different but in my occasion 3V3 was orange, 5V was red, +12V was yellow, -12V was blue and Ground was black.
If all voltage pins are the same with the schematic above, then you are set to go with a new power supply!
