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4
votes
1answer
7k views

Why do I get gibrish output to the serial monitor of my arduino mega 2560?

All - Why does my Arduino 2560 report text that looks like this: I©ä I©ä !11<]=I1)!11<]=I1)!11<]=I1!11<]=I1)!11<]=I1©ä é ©ä I©ä I©ä I©ä I© Every time I execute "spi_dev_test" ...
0
votes
1answer
3k views

I2C level shifting and protection

I am interfacing an MCU (CC1110) with Vdd of 3.3 V to a battery gauge IC (BQ27510-G2) with Vdd of 2.5 V. Currently, I am pulling the bus up to 3.3 V with a circuit that I blindly copied from a ...
1
vote
1answer
627 views

Any idea which software was used to generate these circuit diagrams?

And/or: I'm trying to choose a free schematic drawing software, and like the way these two look. I've read related questions about circuit drawing software as well. I like Fritzing, but it lacks some ...
-1
votes
3answers
40k views

Potential difference across one resistor with and without a known current?

Okay imagine you have a voltage supply of 10V and one Resistor of 5 Ohms. Now find the current : I=5/10 = 0.5A So potential difference across that resistor : V=IR=10V .. which proves this statement ...
-3
votes
1answer
74 views

tablet as a keyboard (bluetooth / USB) [closed]

what would it take to get a tablet to communicate with a desktop via bluetooth (or USB)? There are some programs such as remotemouse which do this through WLAN.
-5
votes
2answers
525 views

problem with reading values in case

I am using ATmega32-A microcontroller and CodeVisionAVR compiler. I am able to read values from an AD7798 external ADC successfully. I am also generating wave from with an AD9833 using SPI ...
-4
votes
1answer
326 views

EEG sensing of imagined speech [closed]

I am doing a project on developing a silent speech interface using eeg sensors. The equipment available is ADI powerlab kit which allows the use of three to four elctrodes maximum. My question is can ...
1
vote
4answers
4k views

Basic microcontroller + RF transmitter/receiver plausibility

I am a complete beginner (I have only gone through the beginners book to Arduino + done a few small projects). I want to know if it's possible to connect a very basic/cheap microcontroller like the ...
5
votes
2answers
227 views

grounding connection?

What's the easiest way to connect a ring terminal to the ground terminal of an AC outlet? Are there plugs you can buy that make this easy? I don't need (or want) the line and neutral wires accessible,...
0
votes
2answers
708 views

Automating the measurement of current consumption of an embedded system

I have two circuit board. 1.PCB for battery pack 2.Embedded PC with various modules. I was wondering if there could be an automated way of measuring current consumption by the embedded module during ...
1
vote
1answer
107 views

PN200 replacement

I have circuit that is calling for a PN200 PNP Transitor. However, those are not avaiable in my area. Can anyone suggest a replacement transitor. Thank you
8
votes
2answers
786 views

Transformers as Inductors (Weird Results)

If a transformer's primary and secondary are connected in series, then the total inductance of the result, is greater than the summation of each coil separately. That is to say: \$ L_{total} > (...
11
votes
4answers
16k views

Explanation for Differing Stator Winding Orientations

As a layperson, I'm trying to understand the basic configuration for an induction motor or generator. I've looked at many diagrams and photos/cutaways of stator wiring and I've noticed two different ...
4
votes
2answers
229 views

Question about the derivation of filtering roll off

I don't understand the following step in my notes: It is about filter roll-off. $$H(\omega)={1\over 1+j(\omega/\omega_c)}$$ $$\Rightarrow|H(\omega)|= {1\over \sqrt{1+(\omega/\omega_c)^2}}$$ where $...
2
votes
1answer
6k views

Is it possible to intercept the audio data of voice call in Android? [closed]

To my konwledge, the (voice call) audio data from micphone will be sent to PCM module for resampling, then to modem for coding before sending to air.I am here for asking in Android is it possible to ...
-4
votes
3answers
417 views

RS232 concurrent communication [closed]

I need to interface with a printer equipped with a RS232 port from both my arduino microcontroller and my computer. It means that the printer is connected to the computer through the RS232 port and I ...
1
vote
1answer
2k views

110V AC/ 9V AC power adapter (America) Vs. 220V AC/ 9V AC power adapter (Europe) [duplicate]

Possible Duplicate: Choosing power supply, how to get the voltage and current ratings? I have a device that I brought to Europe from America. It has a 110V AC/ 9V AC power adapter that stopped ...
1
vote
1answer
2k views

9v AC 2000mA power adaptor for a 9v AC 1000mA device [duplicate]

Possible Duplicate: Choosing power supply, how to get the voltage and current ratings? I need to replace a 9v AC 1000mA adapter for a 9v AC 1000mA device but all I've been able to find is a 9v AC ...
-6
votes
1answer
396 views

Toggling problem of D flip flop [closed]

how to do frequency divider by 2 without having the toggling issue ? Since I just want to divide the frequency by half and align that signal with single pulse signal.
25
votes
1answer
139k views

What is the polarity of a car cigarette lighter adapter?

There is a center pin, and two outside tabs. Which are positive and negative?
7
votes
3answers
967 views

Chosing a pulldown resistor

Setup: A digital output from a device is connected to an output buffer to drive an optocoupler. If device power is lost the output will go in high-impedance mode. Problem: I want to make sure that ...
0
votes
1answer
335 views

BBQ iginter power surge

I am building a home beer brewing rig that has several electrically actuated components controlled by an Arduino. The typical scheme is Arduino -> Shift Register -> Relay -> Component. One of the ...
2
votes
1answer
446 views

1.2 GHz Cloverleaf Antenna tolerance

I'm working on building my own Cloverleaf antennas, to work at 1.2 GHz, for the video system on my Quadcopter. At this frequency, what kind of tolerance am I looking at in terms of the length of the ...
0
votes
1answer
162 views

Highly accurate CMOS Squave wave clock signal to drive MF5CN Audio filter

The task is to generate a CMOS (+-5[V]) square wave signal with 50% duty cycle in order to drive a second order active filter IC (MF5CN) with variable or fixed frequencies of 150[Khz], 300[kHz], 750[...
0
votes
1answer
1k views

LF398 Sample and Hold Circuit

I'm having a problem designing a circuit to interface an LF398. On it's data sheet it says that it needs +5 and -5 volts, but I only have +5. My questions are: Can I put V+ on 5V and V- on ground ...
10
votes
3answers
3k views

Advantages of 32-bit 48-96 Mhz microprocessors (such as in Arduino Due)

It seems Arduino Due ( 32-bit, 84 Mhz, ARM-Cortex-M3-based SAM3X8E ) was released today. In addition, clearly there is a myriad of processors in this category ( 32-bit / 48-96 Mhz / ARM ) as well as ...
5
votes
2answers
299 views

How much power can reasonably be collected from ambient background radiation?

It seems that with a coil or simple antenna it should be possible to collect energy from the background 60Hz radiation in any modern home. How much could reasonably collected at low voltages (3.3-5V)? ...
3
votes
1answer
3k views

Resistor value labeling, what does the second number refer to? [duplicate]

Possible Duplicate: µ in the Middle of a Capacitor Rating What does 3V3 or 1V8 mean I have been looking over some schematics for an industrial Laser. Some resistors which have low values, ...
25
votes
5answers
7k views

How do I solder headers so that they always stand straight up?

When soldering headers, usually single and double pins, I flip the board over so the pin rests on the surface and then solder them. They never come out straight. It would be great if someone has ...
2
votes
1answer
868 views

How to start implementing your own computer? [closed]

The question As a first step I need to select a circuit board, CPU & RAM/ROM chips and I/O connectors. How do I select a board that can interconnect all these components? Perhaps you could give ...
0
votes
1answer
220 views

Input impedance of a GenRad 2512 Spectrum Analyzer [closed]

Does anyone know the input impedance on the General Radio Model 2512 Spectrum Analyzer?
9
votes
5answers
12k views

Understanding electrical consumption

I have problems understanding the difference between electrical power and consumption. Can you help me understand what electrical energy consumption is? Let's say that I have a bulb, on which is ...
3
votes
3answers
676 views

Can more than one device read data from GPS?

I have an OSD(atmega88p inside), which is reading data from GPS through serial connection as I understand and I would like to connect second device (FEZ Cerb40) to read GPS data, wondering if that ...
3
votes
5answers
3k views

Circuit short circuit capacitor question confusion

I am really unsure about how to go about this question and which circuits to consider. Here's the question: Determine the value of the current labeled \$i\$ and the voltage labeled \$v\$ at \$t=0+\$...
0
votes
1answer
174 views

automatic datasheet information extraction [closed]

Does anyone know of a way to extract information from a datasheet table ? An example of what I'd like to do is automate the comparison of a given characteristic (say V_dss) from multiple MOSFET ...
5
votes
1answer
2k views

How to drive stepper motor at maximum speed with a higher voltage power supply in hand?

I had a question about "Wantai" Stepper Motor with an Arduino hooked up to an motor-shield. Looking at the spec sheets the max volts and current allowed in that particular stepper motor is 3V and 2A. ...
3
votes
5answers
348 views

Hardware Defined Byte

I would like to make a PCB that sends a specific byte of information through a usb connection. I need the PCB to be as small and simple as possible to fit into a nice thin housing. Simply put there ...
-1
votes
1answer
663 views

Logic needed to read and store values

I am new to programming. I have one input signal from waveform generator. I am giving this signal to one sensor and as well as channel 1 of multiplexer. The sensor output is giving to channel 2 of ...
2
votes
2answers
1k views

Finding/Calculating LED light luminosity / power output

Is there a simple way to determine the light intensity / power output of an LED? e.g. Light output = current x F.Voltage - heat dissipation Light output = efficiency x current x F.Voltage I can't ...
4
votes
2answers
2k views

Floating voltage measurements

Is there a very cheap way to measure several voltage differences of 0.1V to 10V (to ~1% accuracy at 10Hz, say), where each pair of measurement terminals may be tens of volts away from the ground of ...
5
votes
1answer
464 views

Using impulse response to control the system

This post by Olin Lathrop is rather inspiring. The system response is the convolution of the control input with this impulse response, computed every control sample, which is every 500 ms in ...
1
vote
2answers
504 views

Prototyping with a very small surface mount connector/socket

I've got a Satellite modem with a connector that mates with a tiny 10pin by 10pin Samtec SS4 series surface mount connector. The question is, how would I prototype with this component? I am thinking ...
9
votes
4answers
3k views

Does there exist an IC that allows on-the-fly routing of signals?

Do there exist ICs with N input pins and N output pins which, either via EEPROM setting or via on-the-fly control by a microcontroller, allow one to route each of the N inputs to ANY of the N outputs? ...
1
vote
1answer
213 views

Need help with programming an NXTBee on a NXT Lego Mindstorm Robot

I am doing a project for work using the NXTBee NXT controlled by an arduino. But I'm a novice with programming. I am using ROBOTC and when I compile I am getting an error: Calling procedure '...
3
votes
1answer
2k views

How to drive a high-side N-channel MOSFET with low VGS?

Question first: Is there a bootstrap driver that is available in DIP, works similar to the IRS2001, but is OK with a VCC of 4-5V? I'm also a bit limited in the amount of space I have -- is there a ...
4
votes
3answers
3k views

Latching power switch question

I have the following circuit (source: EDN): I understand the basic working principle of the circuit and it works fine when it is powered from a 1.5V source. But when I power the circuit from a 9V ...
1
vote
1answer
11k views

How to read 115200 Baud digital signal on Arduino UNO?

I am a beginner to microcontrollers. I am trying to use Arduino UNO to read data at 115200 Bd. I used SoftwareSerial.h as follows. But I do not think I got correct data. Could you help me take a look? ...
0
votes
2answers
3k views

Power loss from an inductive load

A problem reads "A single phase 50 Hz generator supplies an inductive load of 5000 kW at a power factor of 0.707 lagging ... " How can there be real power loss from an inductor?
1
vote
3answers
1k views

Can we give a bipolar signal to ADC of ATmega88?

Can we send a bipolar signal to the ADC of ATmega88? We know that an analogue signal has a positive value as well a negative value. So can an ADC take a negative value or does it just take the ...
4
votes
3answers
4k views

Is this the right way to mount a 2N3055 or any TO-3 form on a heat-sink?

Top view: Bottom view: This is the first time I'll be using a heat-sink on a transistor. Right now these are just placed together. Is the mounting correct?

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