# Search results

1. ### Finding the unknown coordinates of a point, knowing its difference of distances

I've read something about "Multilateration" on the web. I think it does something similar to what I want to. Any information or experience about this technique??
2. ### Finding the unknown coordinates of a point, knowing its difference of distances

Thanks for the reply. But aren't there more than one solution (answer for (xa,ya)) for the above system of equations? Because it seems to be the intersection of two parabolas. You know I need just one answer for the problem.
3. ### Finding the unknown coordinates of a point, knowing its difference of distances

Hi everybody, Assume that I have 3 "reference points", which are some fixed points with known coordinates (known location on x-y plane).Take "A" as an unknown point (I mean a point that I don't know its coordinates). If a system measures the "difference" of distances from A to that "reference"...
4. ### Problem in measuring distance with time-of-flight of radio waves

Two other questions: 1. Assuming that I have found the exact dealy in the receiver and the transmitter (delay of demodulator,stages,etc), can I suppose this delay to remain always the same (over time)? 2. Even if I ignore the problem of dealy, what about the accuracy of clock frequency? Every...
5. ### Problem in measuring distance with time-of-flight of radio waves

I thought about it again and I came up with a question. Your suggested system works like this: A transmits a signal to B , B responds to A and finally A calculates the elapsed time between sending the signal and getting the response (round trip time). In practice, when B receives the signal it...
6. ### Problem in measuring distance with time-of-flight of radio waves

Yes, you are right. Sorry I made a mistake. Actually I had an idea like yours in my mind, but I couldn't explain it correctly! I just wanted to emphasize on time of flight. This method is OK. But as I said, my problem is with the hardware. As the clock frequency is not high enough, how can I...
7. ### Problem in measuring distance with time-of-flight of radio waves

Thanks for your reply. I know there are other methods like measuring the phase or signal strength, but I'm really interested in using time of flight. The basis of my project: The transmitter sends a signal (a pulse, for eaxmple) and after a predefined constant delay, it sends another signal...
8. ### Problem in measuring distance with time-of-flight of radio waves

Hi dear friends, I've decided to build a simple system that measures the distance between a RF transmitter and a receiver (range finding). My idea is based on measuring the Time-Of-Flight of the radio wave ,with a digital circuit (also a microcontroller may be used). I need an accuracy about 10...
9. ### Problem with microphone preamplifier circuit

Hi, Please have a look at this circuit which I use to amplify the output signal of a capacitor microphone. I watch the output of the circuit on a oscilloscope, but it seems to be random noise.When I speak to the mic I can't see anything similar to audio signal on the output. Only when I hit the...
10. ### [SOLVED] Problem with ARM microcontroller ethernet controller and DP23848 chip

Fortunately I fixed the problem myself! The problem arised from CPU clock. I hadn't configured PLL correctly. So remember you MUST always configure the clock prior to using the ethernet unit.
11. ### [SOLVED] Problem with ARM microcontroller ethernet controller and DP23848 chip

Problem with ARM microcontroller ethernet controller and DP83848 chip Hi, I've written a simple program for LPC1768 microcontroller (ARM Cortex-M3) in order to interface ethernet network, I just need to receive network packets at the first step. I've used DP83848C chip as the PHY (via RMII...
12. ### Color Sensor for Light

Well, so what is your suggestion if I want to make a sensor (for color of light) without using that dedicated sensors?
13. ### Color Sensor for Light

Does transparent colored plastic really filter the light? e.g a red transparent plastic (or glass) blocks blue light and green light? I've tested it ,I put a red transparent plastic on a source of green light, but it doesn't seem to filter the light effeciently, I can see the green light...
14. ### Color Sensor for Light

thank you ahsan_i_h ! TCS230 is a good IC but unfortunately I'm not able to use it for some reasons (it's not available in my country, price,etc). What are these filters? Can I build them at home? Are they available on the market?
15. ### Color Sensor for Light

Hi everybody. I need a color light sensor for my project, I mean a circuit or IC that is able to detect the color of the light (And I want to send its output to a microcontroller). I've seen some of the related projects on the internet which use three LEDs (Red,Green,Blue) to radiate light and...
16. ### Typical Refresh Rate of Small LCD Screens

Hi everybody, I need to know the refresh rate of LCD screen of mobile phones. There must be a vertical refresh rate (vertical sync frequency) for mobile phone's LCD , like a PC LCD monitor, isn't it? My own phone model is Nokia 6120 but I couldn't find anything about its screen refresh rate...
17. ### Screen Refresh Rate of Nokia mobile phones

Hi. In order to do a mobile programming project, I need to know the maximum refresh rate of LCD screen of my Nokia mobile phone. Actually I want to know how fast I can draw graphics on its screen (At what frequency it's possible to redraw the screen contents?). My phone model is Nokia6120. I...
18. ### Digital circuit inputs turn on thesholds, turn on voltage?

It think Audioguru answered your question: Many digital ICs are available in both TTL family and CMOS family. The main advantage of CMOS is that it uses low power (low current) although it may be slower. This is the main difference but in general you can't say CMOS can do sth that TTL can't or...
19. ### How does a VGA monitor support different modes? (How to choose signal timings?)

Thanks for your reply. So , I must ONLY use the standard resolutions and standard frequencies for clock and sync signals? Ok, but how many standards are defined for that? Is there a complete list of all VGA standards availabe? And what's more, Do all the monitors support these standards? How do...
20. ### How does a VGA monitor support different modes? (How to choose signal timings?)

I'm confused by the signal timings for a VGA monitor. We know that the VGA standard have different modes (There is a different resolution, refresh rate and signal timing for each mode). Also the pixel clock frequency, at which the VGA adapter device must send the image data, differs for...