Can I Use Opto isolator to protect my arduino and other components connected to its 5V pin

So I am using two power sources. 5V from arduino and 12v 2A transformer for my stepper motor. 5V and 12V share common ground. My problem is that other components(LCD display, Water level Indicator) connected to 5V source from arduino won't function correctly when 12V is on. I think because my 5v isn't isolated and excess voltage from 12V goes through it.  I use 12V to power up my stepper motor and relays. Can optoisolator do the job in isolating these two voltages voltages?

Question by AlyzhaO   |  last reply

Can I convert .sch file to .docx file?

I created my schematic diagram on express schematic and i need to tranfer it to microsoft word for documentation. Can i convert the .sch file to .docx file? .can anyone teach me how to?

Question by AlyzhaO   |  last reply

how do you program a arduino motor shield? Answered

I have an arduino motor shield from seeed studio and i have to learn how to program it in two weeks from today today is 12/31/12 well i barley know how to program arduino but i will learn step by step by the way it is an arduino uno not rev 3. PS if this link is any use to you here you go

Question by FarmerKJS   |  last reply

Is it ok to use two ground pins in arduino?

I'm utilizing two power sources... the one that comes from arduino (5V) and one 12V transformer to power my stepper motor. In the 5V pins I am powering up LCD display and my water level indicator. Now, I utilized two ground pins for the two voltages (5v arduino, 12V) . At first I only used one ground for the two voltages because they need to be in a common ground but voltages are jamming together (i think) because every time 12v is on , the lcd (which is connected to 5V) isn't functioning well. So, I decided to use another ground from the arduino and connect it to my 12V source so it could still have a reference point to my 5V supply. It worked , the LCD functions well but another problem has arised. The rectifier diodes in my 12V transformer gets really hot. What could be the problem? . Does it have anything to do with using two separate ground pins in my arduino?

Question by AlyzhaO   |  last reply

Projecting onto glass

Alright here's my question, I know I've seen it done a couple places, the first image I could find as an example was just this : (just see below)What kind of glass do I need to do something like this? I'd like to build a table of sorts out of glass with a projector built into the frame under it to project upwards onto the glass, then eventually perhaps adding an IR sensor and work towards building a touchscreen/MS-Surface-like table. Any thoughts? Obviously its not normal glass or the projector would just pass through it

Topic by ianidas   |  last reply

DIY ±18VDC to power a dead cordless drill

Hi! My last battery died on my cordless drill and i'm trying to transform it to a corded drill. My plan was to use a microvawe transformer along with a bridge rectifier (KBPC5010  Bridge Rectifier Diode, KBPC Series, Single, 1 kV, 50 A, 1.2 V, Module, 4) to power the drill. 120VAC from the wall to, I wish, 12to18VDC. The problem with this is the voltage given by the output of the microwave transformer is of only ±3VAC. Any sugestion?

Topic by rudecam   |  last reply

Controlling two servos with one pin and a NOT-gate

Here's an interesting idea. It may be possible to control two servos independently with only one output pin and an inverter/NOT-gate. Normally, a servo is at its 'center' position when a pulse is 1.5 ms & its angle (or speed for continuous servos) is based on the difference between the length of time of the pulse it received & the base-time of 1.5ms. The servo itself does not react to the time BETWEEN pulses however. If the signal was inverted, the result would be a pulse with a time being that of the time between pulses of the initial signal. If the width of a pulse and the time between pulses can be independently controlled, then it would be possible to control one servo with the signal directly, and another servo using the inverted signal. I found something similar here [] but it seems to be intended for 'reversing' the signal used to control one of the servos.

Topic by Michael_Everett_Feder   |  last reply

How to make a circuit for the ATmega328P-PU?

I have been wanting to build a standalone circuit for the ATmega328P-PU but i understand where to connect the power to it, i have been looking online and all i can find is how you make a DIY Arduino and they only show pictures of the wiring that does not show what is connected to the prongs coming off of the ATmega. I have generated a list of questions below: How to provide power to the ATmega through USB what prongs i should connect the power to. what prong does what. I put a picture of a diagram of the ATmega below that i found online for reference.

Question by bman46   |  last reply

How to upload a sketch to a barebones arduino? Answered

Hey friends! After seeing a few instructables on making a barebones arduino i decided to make one. But there is a problem. I cannot find and FTDI serial to USB cable around. Also i read that a duemilanove can be used to upload the sketch. I have an UNO. Can it be used to upload sketch without taking off the ic because i think that i will be damaged while snapping off. Plz help.

Question by DELETED_Snehil1101   |  last reply


Hello sir, i am stuck with my arduino uno. in the manage driver list i cant see arduino uno's name so what to do please tell

Question by maitrteya   |  last reply

wifi extension

Hello all! i need some help, is there a way i can make my wifi signal stronger without modifying my router, i normaly like to research/ play games in my room, where i only get 3/4 out of 5 bars. the router is under a tv and directly iv front of a wall separating me from it a simple map looks like this                                                                                         me                                                                            ----------------------------------------|                                                                           | 10 ft  thick wall (wood and sheetrock)                                                                           |                                                                           |                                                                           ----------------------------------------                                                                                                    router

Topic by Di Immortales   |  last reply

Help with Stepper Motor and Slip Ring

Hi All,    I need to figure out how to get power and control signals from a stationary computer / PIC into a series of subsequent rings via rotating joints. Ultimately, what I want to build is a form of motorized gyroscope that can transmit power and control signals to the inner ring motors. - I'm using a Raspberry Pi 2 to control three Stepper Motors. - The motors are getting power from an old AC/DC wall adapter. - I currently have 3x NEMA 17 stepper motors     - Yaw Motor/Axis     - Pitch Motor/Axis     - Roll Motor/Axis - I've got 2x 12mm 12 8-wire slip rings that I hope can be used to send the control signals from the Controller to each motor. The problem is that I'm not entirely sure how to connect those components together, let alone how to connect them to bearings to minimize tension on the motor shafts. (I'm a software engineer, not an EE or ME.) An example of what I want to build is this: ( However I don't need anything in the middle, I just need a way to control the rotation of each ring layer independently by the stepped motors ) If anyone can point me in the right direction it would be much appreciated, Mike C.

Topic by MichaelC87   |  last reply

LCD and MB

Hello im the new guy here and im wondering what can i do with these parts i had a lcd monitor and the motherboard is fried and jjust the screen is ok what can i do with him somehow to use it or something and also i have GPS motherboard it works fine it has a 8gb disk space i dont know what to do with her i have old motherboards for dekstop computer mini itx,msi..... and i have two laptops one the motherboard is fried and the other one doesnt have a problem but its too old and if somebady can give me some examples in what can i convert this things Thank you      

Question by VlatkoA   |  last reply

adding aux line in directly to boombox ampli

Hi guys i am Ramanta from Indonesia i have an old boombox, Sony CFS-1110s (similar mechanism with CFS-1100s) what i want to do is add an aux input to them. I have seen a lot of instrucrables about it, but nothing about this model. I find a similar unit here the aux in is conected directly to the IC Amps pin. I have the IC diagram, what i dont understand is this model have a dual IC8207k. One for each channel. TA8207K is a stereo IC, so how do i do the wiring? For single IC its just INPUT1-INPUT2-GND. In dual setting they have 4 input and 2 ground. I dont want to use any tape adapter since its sound terrible here i attach the complete diagram and schematic in PDF please give some tutorial, im a beginner in this kind of thing) hehe my email sorry for the bad english :D

Topic by ramanta   |  last reply

Covering a stickered laptop with epoxy resin? Answered

Hi! I recently got a new laptop and I covered the top cover with stickers and it looks pretty good if I do say so myself. I didn't want the stickers to peel up or anything so I went on over to the hardware store and bought some Krylon Crystal Clear spray, which is an acrylic lacquer based spray. I sprayed a whole 32 coats on that sucker and it was still paper thin. It's as if I simply made the surface shiny, and the stickers could still easily peel up. So I did a lot of research and I found a lot of things but I figured a 2 part pour on epoxy resin was the best choice. It's thick, self leveling, self doming, and it cures instead of air drying. My goals from the beginning were to eliminate surface texture altogether. I want the end product to be like those table top bars with stuff encased inside within a clear glass-like coating. I have found a lot of stuff, but I have yet to find anyone that has done what I am trying to do, and since it's my new laptop, I have concerns. How durable will the epoxy be? I want to make sure that it will be able to withstand the life of a college student, although I'm a quite careful one at that. Will the epoxy have any trouble bonding and staying bonded to the Krylon spray? It's an acrylic lacquer based coating according to the company. I don't want the shell of epoxy separating from the top of the laptop. I'm worried about bumping the edges and having the epoxy chip off or just separate altogether. That last question is the main and most important one, really. The last thing I want happening is for the epoxy to dry and then separate from the laptop or crack or chip or something. The epoxy I've settled on for now is Envirotex Lite, I'm not sure how much epoxy differs between manufacturers. I've emailed several companies asking lots of questions and I've gotten a lot answered, but these ones have yet to be solved. Thank you so much for reading this and any input or advice would be greatly appreciated!

Question by jcbeaver7   |  last reply

Arduino + L298N controlling bipolar stepper with pot speed control and speed on lcd (also on lcd thermistor temp in C)?

Lcd 16 x 2 Motor 10K potentiometer L298N is a module Arduino controlled How can i control the motor and lcd?

Question by bonze77   |  last reply

Auto bed levelling probe problems on marlin.

When i try to set the probe routine (g29) the servo dose not deploy the probe. Also if i try it with the probe down (m401) it will try to probe but the motors don't move so it ends up probing the same spot 3 times. (on the lcd it thinks the motors have moved but they haven't) 3- point probe mode Marlin 1.0.3 dev These problems are when i try on pronterface. My config file:,file=58699,filename=Configuration.h

Question by bonze77 

Need help with state transition table and diagram

I need to make a sequential circuit which output will used for my combinational circuit input. I already made my combinational circuit which gives output in 7 segment display. I need to show EC1013 in & segment.The binary to show them is given below. 000=E 001=C 010=1 011=0 100=3 You can see I need to show EC1013 where 1 is repeated again..thats why I am unable to figure out the state  transition diagram for that... I tried to simply make the state transition table according to my output  and used K-map to minimize that and build that circuit..but it stucks in the 10 loop.. after showing EC10 it keeps on showing 10101010 forever.can some one help me with that

Question by TanvirM1   |  last reply

5.5v DC supply on a 12v LED ?

Hi thanks for reading. I'm building (from the ground up) a set of 3x6" > Amplified 3 watt stereo Planar full-range speakers to be powered from a Cell Phone. I have most of the required parts which are many. One of the parts of the system I'm installing is a Blue LED (Amp On) Indicator. I'm running the system from a USB Charger or a Cell Phone USB Port at 5.5 volts. I went forward and ordered the Blue LED's and they haven't arrived yet so I can't test. These LED's are from E bay with little info of course. They are said to be standard, Blue 2mm 12 volt LED's. (Not Ultrabright)  ------------------------------------------------------------------------------------------------------- My question to you who may know: Are (Rated) 12 volt LED's likely to light from a 5.5 volt power supply? I guess my confusion is between the 12v claim and the LED Color Standards for a Blue LED.. ------------------------------------------------------------------------------------------------------- Without knowing the complete situation, here is the resistor value I've been able to come up with based on *LED Color Standards (Blue) and Supplied Power (5.5v): (*Blue) LED calculator: Current limiting resistor value: Source voltage = 5.5v LED voltage drop = *3.5 LED forward current = *20mA (=) Current-limiting resistor needs to drop 2 Volts. The resistor value is 100 Ohms, the next higher standard value resistor is 120 Ohm. The resistor will have to dissipate 0.04 Watts, the resistor should be rated 0.067 Watts, a 1/8 Watt resistor should do it. Final: 120 Ohm, 1/8 Watt. (color code: brown red brown, Silver). (100 Ohm: Brown, Black, Brown, Gold). ------------------------------------------------------------------------------------------------------- Thanks for the help! I hope I made some sense here ;)

Topic by Rexrich   |  last reply

How to convert 12V to 5V for incar use ?

I need to create a cable that will run from my car battery into a device that runs on 5V DC power. It needs to look like this: INPUT: 12V car battery Simple bare +ve and -ve wires OUTPUT 5V 1.25A barrel connector 5.5mm (I beleive) like this one:

Question by SamC17   |  last reply

Best way to switch multiple circuits?

Hi, all - first time posting. I have limited knowledge with electronics and have come across a scenario where I basically need a kill-switch for a cable with 9 ends. I can't find any sort of toggle switch (SPST, DPDT, etc..) that would accommodate that many wires. I started reading up on digital bus switch IC's. It seems a 10-digit one like this would work, leaving one unused.,118/568-8418-1-ND/2765135 My question: is this the easiest solution? I simply don't know what all options exist, so any advice from someone more experienced would be greatly appreciated. Thank you for your time. -Caleb

Topic by calebpaul   |  last reply

Gameboy Screen

Hi I was wondering if it were possible to replace a standard gameboy advance sp screen with a newer, larger screen and how I would go about doing something like that. Thanks!

Topic by greydon   |  last reply

Why is my RGB led strip giving lots of problems?

Hi,      I'm working on project with RGB LED strips with my arduino and a ATtiny84. Basically, what I plan to do is attach the strip to my display cabinet and attach the strip to an ATtiny84 microcontroller which will program the lights. Doing this I have encounter a few problems. As I haven't receive my ATtiny84 chip from the store yet, I'm testing everything on my arduino first. I first attached a normal single RGB LED to test all my programs and it works almost fine.       My first problem was when I attached 3 potentiometer(pot) to the arduino to control the intensity of each pin(red, green, blue). It did as it suppose to. When I turn the knob the brightness increase but as I'm reaching its maximum it drops back low again. So basically as I turn the knob gradually increasing, the brightness increase gradually from zero to it brightest then drops. I have attached a screenshot of this program below. I think it may be the connection between the pot and the arduino as they are quite sensitive but I'm not sure.       My second problem is when I replaced the single RGB LED with the RGB strip, MOSFETs(TIP120) and an external 12V supply it worked like before. I attached a couple of pictures of the layout below. However, when I set all the pins to low brightness the red and blue is turned off but the green led did not. The green led is dim but not completely turned off like the others. Why is this so? I'm very sure its not a defect in the strip. I hv also a attached a picture below of it.       My third problem is when I bought the three MOSFETs from the store I got one slightly different one although with the same label of TIP120. I have also attach a picture of the MOSFETS below.  The pin that is connected to this different MOSFET seems to act the opposite of its values. As in when I set that pin to low brightness it will be bright and vice versa unlike the other two. I can easily buy another one but I would like to know why this happens.       This is not really a problem but more of a question. As you can see I attached a 1k ohm resistor between the MOSFET and the arduino output to limit the draw of current. I would like to know what would you recommend the value of the resistor because I do not want to damage my chip. Is 1k enough?       My second question is I'm using a 12V 2A power adaptor as my power supply and a L7805 voltage regulator to provide a 5V power for my ATtiny84. However when I connect it I do not get a stable output and its value is around 5.3V. According to some videos I should attach a 0.1 microFarat electrolit capacitor to the input and a 22 microFarat electrolit capacitor to the output in parallel, however when I do so my output is still not stable and is around 5.8V which is too high for the chip as the max Vin for the chip is 5.5V. So what should I do?       My third and last question is my power adapter heats up when its powered but not connected to the circuit. Why is that? And my MOSFETS and voltage regulator gets hot occasionally. Should I attached a heat sink? Is this circuit possible to be left on 24/7? and how much power will it consume?       Sorry for the long post, I'm fairly new to electronics and I'm just a student  who is trying to learn electronics on my own. I have been working very hard on this project and I hope I get the best out of it. Sorry for the bad english too. Any help and comment will be much appreciated. Thank you very much!!

Question by KhayhenS   |  last reply

DIY Small Image Projector PLEASE HELP!!

Hi there, This site seems quite informative but still couldn't find what I am looking for, I really hope you can help me. I am actually trying to achieve the exact opposite of what most people try to do with their DIY projector builds. I am trying to make a "small image" projector. I have tried using all kinds of combinations of focal calculations but cant seem to get the result that I am looking for. I will be honest with you, I am very new to this and still acquainting myself with it. I want to build a projector that can project an image as small as 10mm across to as large as about 50mm - 70mm across without loss of image clarity. I also want to be able to project the image from a short distance, up to maybe 300mm away. I will use a 7" LCD (1280x800) and want to be able to build this projector no larger than an A4 size sheet of paper. is this achievable? if so, how would I go about building it? would you be able to give me any advice, ideas?   Any ideas are welcome as my head is about to explode :-(   Cheers Jon

Topic by jwindsor2   |  last reply

need replacement for Koolatron heat exchanger Answered

My refrigerator died. the heat exchanger won't test. It's 3.75 x 4 inches without the radiator fins. 40 watts DC. Apparently Koolatron doesn't carry them, planned obsolescence is unethical (unless you're a shareholder). Where do replacements come from?

Question by Jakey2   |  last reply

Surely there's an app...? (Software recommendations, please)

So, I have this new HP Sprout that I totally wasn't expecting. It's got a large touchscreen and this cool projector-scanner-touchmat combo that should be really useful for... something. The first thing I actively want is to be able to create files for my laser cutter (running Lasercut5.3), just by drawing with fingertips or stylus.  In my head, I see a version of Inkscape that works on the touchmat, but only responds to the stylus (to save weird lines from knuckles, elbows...).  I have Inkscape downloaded, but it won't work with the touchmat. Second, it would be nice to start learning how to create are actually 3d already, that could then become lasercut-able or 3d printable. Again, it would be nice to use the full potential of the machine, so what software would you recommend? Third... what?  have you got any cool ideas? On top of all this is the consideration of cost.  Free would be nice - if you are a software developer, I don't mind having a go with Beta products (I'm known for breaking code, so if it can survive me...).

Topic by Kiteman   |  last reply

Schauberger Repulsine 3D files?

I am trying to design a model of Schauberger's Repulsine in Sketchup, maybe even try to print it once complete. For this project  collected all sorts of images and dcuments from the web to get at least most components covered, although it is impossible to get it all... I found the two "wave" disks on Thingiverse, which is already quite a good thing, so everything else will be scaled around these models. My problems so far: Top top cone contains a series of pipes shaped like the horn of a Kudu and on top of that following the shape of inverted egg. There are images to be found on the web but I have a hard time creating this in Sketchup. It is like two twisted spirals that are on top of each other so both ends are wide, the middle is thin. Ok, I give up, have a look instead: If you know where to find a 3D model lke this or how to create these shapes in Skechtup please let me know.

Question by Downunder35m 

Is there a way of connecting a pot or buttons to control the led lol matrix display?

I would like to control the matrix shield with buttons and/or a potentiometer if that is possible thanks.

Question by kwynne   |  last reply

Help me to find me Ground and Voltage on my Cpy ...

Hello Guys , i need your help .  I want made that : (Hot plate ) And i have a Cpu but i dont know where is the Ground and Volt pin . information about me Cpu : Intel® Celeron® Processor in the 478-Pin Package Datasheet : If anybody can help me =D

Question by draknars   |  last reply

How would I wire my high voltage capacitor bank? Answered

So I'm having this project that calls for a high voltage capacitor bank. I bought 10 450V 330uF electrolytic caps and want to make a 2kv (with safety margin) cap bank. I wired 5 of them in series and I end up with 2 sets of caps. My question is how would I connect those sets in parallel? Do I just connect the ends together (exhibit 1) or do I connect all the caps together (exhibit 2)? Thank you for reading!

Question by mr.derpinton   |  last reply

HMC5883L with external magnet

GY-273 HMC5883L Compass A. I'm waiting for my chip to arrive and will attach it to a RasPi. B.  My question is: if I align my chip to "N" then rotate a magnet round the chip - i.e. a weathervane - thoughts on how that might work? C. Can my magnet, if too strong/close, damage my chip? Thanks

Topic by liderbug   |  last reply

How can i adjust the brightness on the arduino lol 9x14 matrix sheild? Answered

The other day I recently bought the lol white smd matrix shield for Arduino it to me minutes to set up, and then I wanted to adjust the brightness as it was too bright would be good to set the brighness with a pot or buttons so I turn the pot and it adjusts the brightness or press a button to change the brightness thanks for help. (Beginner in arduino not quite got my head around the programming yet.)

Question by kwynne   |  last reply

List of categories??

This is a question about the site, not about the @#$% forums! IS there a PAGE that LISTS all of the CATEGORIES for INSTRUCTABLES somewhere? I don't understand why there isn't just a button on the home it inconceivable that one might want to choose from a list of categories of instructables to look at? I don't live here so every time I visit, I'm like a new visitor and confined to the instructables that are listed in emails BECAUSE I CAN'T FIND A @#$% LIST OF CATEGORIES TO BROWSE AND CHOOSE WHAT I WANT TO LOOK AT FOR MYSELF!! #@$%!!! The concept is SO good that the inability to find a list of categories is INFURIATING!

Question by GenerallyOdd   |  last reply

My Wii will no longer play Wii games. What's going on?

I've had my Wii for a little over a year now. It just stopped playing Wii games about a month ago, but it still continues to play Gamecube games perfectly fine. I haven't tried modding it or anything, it just stopped working out of the blue. What is wrong with it? And is there anything I can do? (It's not under warranty anymore...)

Question by moviemagicman33   |  last reply

Where can I get a small radio receiver that I can implement on a circuit board?

I was planning on making a top secret circuit board. One of the thing this circuit board needs to be able to do is to receive a radio signal (I think radio would be the best for this because its simple, and can be transmitted easily through walls, but tell me otherwise). The radio transmitter would only have to send two different things, such as on and off or I and 2 for example. Because of this, I wouldn't think I would need anything hefty to receive/send. I'm not 100% sure if I can easily translate either of these two signals into a circuit board so that I can easily say: if signal = 1 then function 1 else if signal = 2 then function 2 would I need another part to do this? As in if I receive signal 1 then it activates wire 1 and etc. I'm mostly looking for a part that I can purchase for the receiver and transmitter (the transmitter does not have to fit on a circuit board), but would be happy with some DIY goodness as well.  :) Thank you for your help

Question by HarryA3   |  last reply


I have seen RFID wallets, sleeves, and cards.  I like the IDEA of RFID blocking cards that you sandwich your credit cards between. So, my question is thus... If I had two cards made of 21 gauge aluminum and placed them on in the last pocket on both sides of my wallet, would this block the RFID scanners?  If not, then what would it take? What just programming some RFID chips and put them in my wallet to eff with the scanners?  I know there are things like this in the market, but very over priced.  I have contacts in the RFID scanning and deployment world, so it would not be hard for my to get my hands on this stuff. What do you all think!?

Topic by benjaminleebates   |  last reply

arc welder/spot welder? Answered

Can an old small arc welder be used to make a spot welder? It's a 60 yr. old Grindl. A stamping on it says input amps 20, sec. amps rated .80- 80, welding volts 20, max open cir volts 80.

Question by hjones47222222   |  last reply

Advice for a buzzer element

Hello I am developing a small device which requires  a sound alarming. The idea of the device is to be attached to your phone for example and if you wonder where your phone is, the device will turn on the sound alarming in order to give you information for its location. So, I am searching for a buzzer element which: - consumes up to 3.6 V; - is small (diameter up to 20 - 25 mm) and thin of course; I decided to use a buzzer element similar to this one but I am not sure if it will do the job. I am concerned about something else, I have a buzzer at home which produces sound of high frequency and when you close your eyes it is absolutely impossible to find out where the sound comes from. Can somebody help me, please? Thanks a lot!!!

Topic by paveltashev   |  last reply

Questions regarding a project?

Hey Guys, Recently I found an instructable that I doubted would work so I thought that I could ask a few questions about it here. (Schematic: 1st thing: Will this work? 2nd thing:This circuit is designed for 120v AC, what would I have to do to make it compatible with 240v AC? 3rd thing: Explanation to how this works. 4th thing: Which button of the TV remote will this work with? Thanks in advance. -Prickly Potato

Question by SA-DIY 

How do i unsubscribe? Answered

I have accidentaly subscribed to a few instructables and want to unsubscribe.

Question by imthatguy1125   |  last reply

peer to peer communication between Arduino Micros, serial? half-duplex?

Hello all, I have a few Arduino Micro units, and need to connect them together (in a mesh network) so that every unit in it is interchangeable, meaning that any unit may be in connection with more than one unit. As the Master/Slave form is out of question at this stage (because any given unit cannot be both Master and Slave at the same time, of course) I decided to go for a simple serial communication. However the Arduino Micro units (and frankly none of the Arduinos) do not have sufficient serial pins and I was advised to use Soft Serial instead. I was looking into the pin out of the Arduino Micro but cannot quite figure out which pins I can use for the serial comm.; I need 4 to 6 serial communications. If not Micro, what other Arduino (or any other solution) would you suggest? Each unit needs to have the following information ready at its serial ports: - its ID - its MAD - sensor value (analog or digital) Any help is much appreciated, as the nature of the problem may not be changed. So I need to solve it as it is. Karim.

Topic by karimskarim 

how we can adjust the frequency between remote and receiver of a door bell ?

Http:// how we can adjust the frequency between remote and receiver of a door bell???

Question by HaR2   |  last reply

What different frequency meter and counter? Answered

Dear all.. Please help me to know : what is difference frequency meter  and  counter between 2 devices  (please see photo) Thank you so much.

Question by lam   |  last reply

What to do with a bricked all-in-one pc?

I have a bricked Dell Studio 19 All-In-One PC, and wanted to know if I could use it for something. It was bricked by a failed BIOS update. There was a program from dell which came installed and updated any other of their software and drivers on the computer. Only after the failed update I found out that updating the BIOS is really unnecessary. The only fix I know for the motherboard is replacing it, and the only place I found out that refurbishes them are from a company in the US, and it's not cheap at all. (I used to live in the US, and moved to Brazil later) Well anyway, I wanted to know if I can use the computer for something else, like use the monitor for a different computer and use its bluetooth mouse and keyboard on a different computer too. I think the only thing really useful in it is the processor which is already old (Intel E7500 and a 320GB HDD). Thanks for the help!

Topic by nickfaraujo   |  last reply

A Good Electronic Project For a Beginner.

May I ask for something which is good and nice to create for a beginner like me. I don't really have an idea what to  make. I just hope you'll help me.

Topic by imatrianidar   |  last reply

How do i keep the LED on the whole time with logic 1 and turn off only when sending logic 0 between arduino and RF 315?

Good evening sir. I am a college student taking electronics enginneering. i would like to ask for help if you don't mind regarding the use of arduino to control the on and off states of LED. I was hoping you can help me with my programming since the LED lights seem to be blinking only upon receiving logic 1. How do you keep it on the whole time with logic 1 and off only when it receives logic 0? Thanks!

Question by JessaY1   |  last reply

Would it be possible to make a 3D scanner using 4 flatbed scanners in a square setup and custom software?

I was just wondering... 3D colour scans possible using old, spare or salvaged flatbed scanners? I have little knowledge about how it works and am purely curious. Thanks :)

Question by lshoesmith   |  last reply

Help with ipad camera connection kit

Hello all can you please help me, I want to make a camera connection kit to my ipad but there is no single way, how can I do that, i found a lot of it on the net (called otg cables)

Topic by msaad11   |  last reply