# All Questions

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### Cheapest FPGAs? [closed]

How cheap do FPGAs get? I know they're more expensive than microprocessors of comparable capability, but I wonder if there exist FPGAs that could contain a Microblaze soft core running Linux, while ...
• 12.5k
807 views

After my embarrassing mistake by having the component in backwards, I'm wondering if anyone has advice for the newbie (or expert) on reading datasheets. What conventions are there which aren't ...
• 428
364 views

### Choosing a switching device

I am overwhelmed with the variety of switching devices. MOSFETS/BJTS Relays(mechanical/solidstate),optoisolated solutions, etc.. I need to support 15V, 60A bursts, should be high efficiency, and ...
• 2,326
2k views

### Desoldering an SON package

I have recently discovered that my AVR Dragon has a busted voltage regulator (see this). I am trying to remove the voltage regulator IC so I can perform the mod specified on that page, however it is a ...
• 4,987
1k views

### How do I detect open-source licence violations by companies?

Let's say I have an open source project with a license that prohibits commercial uses. Then comes along a commercial product with striking similarities in functionality/hardware. How would I go ...
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3k views

### I don't get the Arduino concept

I have been struggling with making an Arduino for a while (was successful in making a breadboard version using an ISP programmer cable). They say that the Arduino bootloader is made so that no ...
• 3,847
8k views

### How can I tell how much juice a LiPo battery still has in it?

Suppose I have a circuit that draws its power from a LiPo Battery. I would like to know how much power the battery still has in it. Ideally a circuit of power level to voltage will be best .. this way ...
1k views

### Arduino with cell phone

I am trying to simulate button presses on a cell phone by using the Arduino to complete the button circuit thus simulating a button press. I figured out I have to use a transistor but I can't get it ...
• 221
443 views

### SBC Recommendations [closed]

I want to get started with embedded development and for my first project I thought of making a caller-ID type of appliance. Here's why I want a SBC for this: I want to be able to locally serve this ...
883 views

### LM335 doesn't seem to work

I'm relatively new to electronics, and I'm trying to make a thermometer using a LM335 temperature sensor. By reading the datasheet I thought it was simple, connect up 5V to a resister, then to the V+, ...
• 428
3k views

### AVR self-programming

According to the datasheet, the ATMega168 can only execute self-programming instructions when running code from the bootloader block. Once the bootloader is complete and the application starts, can ...
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3k views

### Identify processor type from raw binary code?

Not really related to chips, but hopefully I'll get some directions to follow from here. I got a chunk of code, but I don't know what processor it intended for. Are there tools available that can ...
• 395
52k views

### Arduino hooking up LCD without POT

I am using this LCD: Plus I am using an Arduino. I am trying to hook this up but without a 10K pot. How is this possible? Every tutorial I found involved the 10K potentiometer
• 221
1k views

### Shutdown for LT3080 current source

I would like to use a LT3080 as a current source (see datasheet page 17 in Typical Applications Section). However, I need to be able to shut it off. Since I_{\text{out}}=10\mu\text{A} \times R_{\...
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188 views

### Resources to understand robot locomotion and Gait functions

Recently I have been watching Robert Full's talks on TED. He has some obscenely interesting works on robot locomotion. This has intrigued my curiosity and I have been trying to understand his works. I ...
971 views

### Piggy-backing off power amplifier outputs

My motor-scooter has a built in radio, with a small speak either side of the front panel, below the handlebars. It's a JonWay, i.e. cheap Chinese, so I suspect the radio is more suited to developing ...
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467 views

### Rotation span of SparkFun ROB-09065 servo

Does anybody know what the rotational span of the ROB-09065 servo from SparkFun? And even better, is there a datasheet available anywhere?
• 728
464 views

### Removing digital noise in software

I have a design which expects a TTL level square wave from a radio reciever which is fed into a microcontroller. There is some TTL level noise as no encoding is done on the transmit end. I was ...
• 4,987
99k views

### How to clean a potentiometer?

I have a couple of potentiometers that haven't been touched in quite some time. In fact, probably not in 15 years. So now they produce noisy output, presumably from oxides or some other crud that has ...
• 19k
8k views

### How to Determine a PCB's Power Requirements?

Disclaimer: I have very little (almost none, really) electronics experience. I purchased a set of IR illuminator boards off of eBay. The only information that the seller provided was that the board ...
518 views

### logical not circuit?

I don't have much experience with electronics, but I think what I want to do could be cobbled together from a Radioshack. I have a Dig 5006-IP automatic sprinkler controller. It controls 24V DC ...
13k views

### Reading a pin as an input on AVR XMEGAs

I have been messing with AVR's XMEGA line. They are pretty amazing microcontrollers. However, Atmel changed much with this new line. I am trying to detect a pin going low. I have tried to set the <...
• 547
1k views

### ATA Interface for PIC

I've been considering using a NANDrive by SST in a new design, however I wasn't sure how complicated it would be to connect a PIC to the ATA interface on the NANDrive. I did a quick Google search and ...
• 3,869
3k views

### FTDI Basic Breakout - 5V

Can this board be used to upload sketches to the Arduino. I tried by hooking the TX port on the FTDI Basic Breakout to RX port(Pin 2 on the Arduino) and RX port to pin 3 on the Arduino. But so far I ...
150 views

### Prototype Options For Medium Current Application

I'm looking for the best option to develop a medium current (approx 1-2 amps) prototype board. Should I be using perfboard, Vero/stripboard or etching a custom board? Or are there any other options ...
4k views

How do you read the numbers on a rectifier diode? It only says "06" (or "90") on it (twice, once horizontally and once vertically). I figure I'm supposed to assume this is a 1N4006, but I'm a bit of a ...
• 221
4k views

### Does CPU pipelining always imply a multicycle datapath?

I'm studying the MIPS CPU and I have a very basic question about the datapath. Since the MIPS CPU uses a 5 stage pipeline, that means that the pipeline is using a multicycle datapath, correct? If a ...
4k views

### Solder Flux Classifications

I was at Fry's yesterday, looking for some thin solder to use on an Adafruit kit with through-hole components. Two of the solders I found were labeled RA Flux and No Clean, respectively. An engineer ...
• 3,720
626 views

### What type of connector to use for pressure contact?

I'm designing a robot gripper that needs to pickup an electronic device (the size of half a laptop) and move it around. The problem is that when the device gets picked up, I need to establish a USB ...
• 791
885 views

### Passive listening to USB communication

Is it possible to passively listen on low speed USB communication? Suppose I connect a logic analyzer to D+ or D- line, will I see a valid data?
• 395
741 views

### When are MIPS control signals generated?

Are the control signals for a given instruction generated within a single cycle for the pipelined, the multicycle as well as the single-cycle implementations of the MIPS32 datapath? I think they ...
223 views

### Robotics custom search engine

I made a google custom search engine: robot cse. Any sites I should add to the list. http://forum.microchip.com/     http://www.avrfreaks.net     http://www.societyofrobots.com/robotforum/
1k views

### Dual Role USB device on AVR

Is it possible to run both USB Host and USB Device controllers on top of an AVR (ATMega64)? Specifically, what I'm looking for is to receive data from a usb keyboard, and simultaneously sending ...
• 395
382 views

### Support for MSP430x5xx processors on MSP430-gcc

How would I add support for a new MSP430 processor type on MSP430-gcc? E.g. msp430x5xx series. I understand I must produce the relevant .h/.o files but how do I generate/integrate those in msp430-gcc ...
• 545
806 views

### Help me find an adapter USA --> Israel [closed]

I just bought a cat feeder from the united states, and brought it to Israel. Israel has 220V power sockets, and the device (that came with the timer below) doesn't fit, obviously. The problem is I ...
5k views

### What are 'return' pins?

On a VGA connector, there are numerous 'ground' pins. Three of these are Red return, Green return and Blue return; But why does each color component have its own ground pin?
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716 views

### logic triggerable strobe light circuit

Does anyone have a circuit that will trigger a strobe light to flash in response to a TTL logic signal? Specifically, if I have a strobe circuit capable of flashing 1000 times per second, it seems ...
• 19k
2k views

### Isn't it overkill to use a regulated power supply for a nixie tube?

I've seen any number of nixie tube designs on the web that use regulated 170V supplies for the nixie tube anode. Wouldn't it be possible to use unregulated, half-wave rectified 170V peak power for ...
• 19k
515 views

### superscalar CPUs and data dependencies

I'm learning about superscalar CPUs and I had a question about that and data dependencies. Given the dependencies, RAW (read after write), WAR (write after read), WAW (write after write), when ...
6k views

### Can you base a computer around a 32-bit microcontroller?

We all have(mostly) 32-bit machines at our homes. But the 32-bit machines have a microprocessor in them. I was reading an article about the ARM Cortex. Its a 32-bit microcontroller. Now that intrigued ...
• 3,847
31k views

### "Tristate a pin"

What does it mean to "tristate a pin" on a CMOS microcontroller?
• 3,720
50k views

### Current flow in batteries?

I am reading a basic electronics book: "There are no Electrons: Electronics for Earthlings" and I came across a clever passage about the fact that you need a closed circuit in order for current to ...
4k views

### RJ45 Female Crimp Connector

Where can I find a female RJ45 connector that can be crimped to another cable rather than being soldered to a PCB or installed in a wall or plastic enclosure? Something like this: http://www....
• 1,334
10k views

### Is it possible to drive TTL inputs from 3.3v microcontroller

I need a quick heads up on a problem I am trying to solve at work. I'm trying to connect to a parallel data port on an interface module we use to access smart cards. The port has an 8bit input and an ...
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9k views

### What does the e3 or e4 printed on an IC mean?

So after staring at a few ICs today, I was wondering what the "e3" or "e4" stands for on the top of an IC. For example, here is an e3:
24k views

### Are Common Mode Choke Coils needed on USB?

I was looking over the schematic for the GumStix Palo 43 and noticed they used a common mode choke coil on the data lines coming in from USB. I understand how this design can help remove noise coming ...
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1k views

### Write Once Memory

I've seen news articles talking about how SanDisk released Write Once Read Many (WORM) SD cards, but I can't find anywhere to buy them! I'm thinking of building a project where I'll want to write ...
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453 views

### iCade - making it a reality

So I want to make my own version of the iCade Any thoughts on how I go about doing the hardware side? Has anyone done an unofficial version of this? I'm thinking a combination of: Concave Button ...
• 5,030
5k views

### Best shunt resistor for power meter application?

Looking for a shunt resistor for measuring power usage and was wondering if anyone had any experience with these. It should be capable of handling 110V/20A in-home circuit. EDIT: Energy monitors ...
• 1,923
1 vote