Jump to content
Electronics-Lab.com Community

gg4rest

Members
  • Content Count

    46
  • Joined

  • Last visited

    Never
  1. I don't know if their indian language site works better, but none of their links on their english site work so I can't give you much information on that. Are you creating a PCB? Wireless, from what I've heard, is difficult to make reliable for a hobbyist. Especially if it isn't on a PCB. I've had difficulty occassionally with a wired system and that should be relatively simple. The problem I think with wireless is, if you don't have a spectrum analyzer you can't really tell if your signal is being transmitted in an easy manner. I've done very little with RF so maybe someone else has a more in
  2. Most microcontrollers have a serial interface. You connect this to a MAX232 chip (or equivalent) in addition to some capacitors (check the data sheets). This chip is available through samples from many companies. It basically does the level conversion from the micro to the PC. You then connect this to a DB-9 connector with the right pin configuration (typically only require 3 pins TX, RX, and GND). You should then be able to talk to a PC through a serial port. This is also usually how your will program the internal EEPROM or flash on the microcontroller. I suggest you look at getting a microco
  3. You will also need an instrumentation amplifier (like an INA338 from TI) before the UAF42 ICs. The signals will go from the sensor to the instrumentation amplifier and then to the UAF42 filter and then to the microcontroller. I've never interfaced to a flash drive before, I just would output to a PC for my system. But if you want portability, I guess that an industrial flashdrive is what you are looking for. Sandisk has an article on interfacing a 80C51 (or 68HC11 with some modification) microcontroller to a flashdrive. You might want to check the price on these drives. http://www.sandisk.co
  4. So what you are thinking of is a blood glucose monitor. Most of these currently extract blood from the person and test it using some sort of sensor. Doing a quick search I did find one non-invasive one that used photonic measurements of the eye to determine blood sugar. Some use Spectroscopy. It looks like a rather complicated process from my quick scan of articles because of the small concentrations involved in the blood. There seems to be no electronic sensor that you can buy unless it is built into an already build glucose sensor. I guess you could try to detect the sugar in the liquid by m
  5. Do you mean its concentration in a liquid? Or how much granular sugar there is in a container?
  6. I went to the University of British Columbia in Canada. Does the piezoresistive sensor actually measure force or are you trying to correlate the angle of the piezoresistive sensor to the force? As I recall, piezoresistive sensors change their resistance with angle of bending which doesn't necessarily mean there will be a force generated by the muscles (ie the elbow can be bent at an angle without using any muscle force). How are you orienting the sensors around the elbow to detect force generation (a picture would help me if possible)? Are you trying to determine force at the hand or at the a
  7. So are you actually measuring the electromyogram signal (the electrical signal sent to the muscle)? If so, this is similar to my MASc. So I'll be more than glad to help out. What university do you go to? I need some more answers to help you. Are you sure the signal isn't bipolar? EMG signals are bipolar unless you rectify them. How much detail do you want in the signal? Do you just want to general amplitude or do you want all the detail of the signal? I can give suggestions on reducing the sampling rate and filter cutoffs if I know this. You may have memory problems with 1000 kHz. At 1000
  8. My TVs all have only 2 prongs.
  9. So you decided against a wired link? Texas Instruments has the ICs you are looking for. I don't know if they supply sample parts to India though. http://focus.ti.com/analog/docs/articles.tsp?articleType=brc&templateId=5266&familyId=367&path=templatedata/cm/brc/data/200210_rf_ismhome&DCMP=RF+NotApplicable&HQS=NotApplicable+OT+ismrf
  10. Hi Garvey, You may want to contact that company and ask their pricing for 1 or 2 chips. They say $2.40 and $3.85 in quantities of 100K but you won't be using anywhere near that amount. It might be too costly. Do you care if different people can say the phrase and gain entrance? Or can it be anyone to say the command? Assuming the IC is too expensive. Here is what you could do. For different amplitudes, you could record the signal to memory, scale the signal to its maximum (ie if they said it quietly it would still use the full range). You may also have difficulty with people talking slower
  11. I assume you want to record the voltage as well as display it right? Anyway, to do this you will require several things. 1. A low pass filter (LPF) and amplification 2. An analog-to-digital converter (ADC) 3. A microcontroller (and some sort of flash memory) or a connection to a PC. The low pass filter is to prevent aliasing in the signal when it is sampled by the ADC. The amplification is to size the input voltage to the voltage range of the ADC. The ADC is used to convert the voltage to digital format. Some microcontrollers have onboard ADCs which makes that part a little easier. Plus mi
  12. There is high voltage inside a TV set to launch the electrons through the CRT with enough velocity to cause the phosphor coating to light up. There is also a high voltage for the steering coils to cause the electron beam to curve to allow it to hit the top and bottom rows of the set and to scan across each row. I assume TVs don't have a ground pin because they likely have an isolation amplifier inside them which would separate the TV set from the household power. This would prevent noise from the household power from recking the tv signal. I'm not sure though. The reason that Air Conditioner
  13. This site lets you search for various types of sensors. Most manufacturers will have datasheets for the sensor you are using and likely has circuits in their applications notes. http://www.globalspec.com/ As for books, "Principles of Engineering Instrumentation" by Ramsay has general information on types of sensors and the basics of how they work.
  14. The easiest and probably cheapest examples I can think of are using velocity sensors or accelerometers to control DC motor speed. If you want to get more complicated, you could use some position sensors as well and use two motors and a couple of linkages to make a simple planar robot. Depends really on how much controls experience you have.
  15. Hi audioguru, Where abouts do you live? When I drove from Vancouver to Calgary, there were no FM stations once I left the two major cities. So I was forced to listen to AM because I forgot to put songs on my mp3 player. It was kind of funny because there were some religious talk shows and funny old songs (from the 40s and 50s). And the announcers didn't seem to care if anyone was listening because they said whatever they wanted. As for the drive from Regina to Calgary, it is just about as bad. As for Andbor's problem. It is also possible that if he is using a digital FM tuner, it won't let hi
×
  • Create New...