Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Search results

  1. P

    Problems with AD7730 resolution in a weighing system design

    Re: AD7730 problems Hi, I had also problems with avr and spi. The problem is that: if I am using the spi built-in from avr it happened that some time didn't worked because ad7730 requires clock both when sending and reading data. Therefore I made by my self the spi routines and I had no such...
  2. P

    AD7730 and Crystal Freq. is it critical ?

    the chip should work also at that frequency but it might happen that the performances are not the same like those specifed in datasheet for 4.9152MHz
  3. P

    Problems with AD7730 resolution in a weighing system design

    AD7730 problems Hi again, Some pcb and schematic considerations: -keep signal lines between ad7730 and your micro as short as possible -use decoupling caps for every supply pin as is specified in datasheet for ad7730 and for your micro connect all supply pins to supply line. Decouple each...
  4. P

    Stepper Motor Grounding required?

    Stepper Moror Grounding If the power supply of the digital part is different from the power supply of the motor and you are not using optos, then you have to connect both grounds together. The best place to connect it's a the stepper motor ground point. Try to avoid grounding loops and take...
  5. P

    How to convert SD interface to USB port in a processor?

    usb sd interface Try to use the vinculum series of chips from ftdi. I saw today a presentation and it looks great for such kind of problems.
  6. P

    Problems with AD7730 resolution in a weighing system design

    ad7710 codevision Hi, I didn't understood well what is your problem. In datasheet is specified that is no need to wait between falling edge of rdy and falling edge of cs (page 4 & 36). Anyway if you are using interrupts, there is some time till the read sequence will begin after a rdy falling...
  7. P

    How to interface AD7730 with a controller?

    adc+controller interfacing You asked about ad7730, therefore you already choosed your adc. You can use any microcontroller on the market which have spi and connect it to the adc. That's all you need! All commands are sent via spi interface.
  8. P

    How to interface AD7730 with a controller?

    connect ad7730 to avr First what is the peak-to-peak resolution (no flicker code) that you need for your application? 10bits? If it's more then 12 bits then you have to take very much care of clean supply, noiseless ground, good decoupling. If you accomplish these items then you have a chance...
  9. P

    avr fast division routine for high numbers

    avr division Hi, Does anyone know a fast method to integer divide 2 long numbers (6 bytes)? I searched on the net and i found one which might apply also for avr https://www.convict.lu/Jeunes/Math/Fast_operations2.htm Does anyone implemented or used such kind of methods? Thanks!
  10. P

    AD7730 interfacing with ATmega

    ad7730 site:edaboard.com this convertor is converting differential voltages, therefore you have to check that the voltages applied to AIN+ and AIN- pins are in the range Vref/2 - input range ... Vref/2 + input range if it's bipolar, and Vref/2 - input range/2 ... Vref/2 + input range/2 if it's...
  11. P

    RS485/PIC18F4520-Interrupt not firing for all recieved bytes

    using interrupts for pic18f4520 Try to use termination resistors, maybe you can get rid of this problem.
  12. P

    How to make RS485 (I used MAX1487) power supply?

    RS485 problem! Can you be more specific! RS485 converters are noisy when you are changing between receive and transmit state. Therefore you have to take care with the supply voltage. One solution could be to use a voltage regulator with good load regulation to overcome this issue. Bypass cap...
  13. P

    Boot-strap components

    I made some trials with ir2184 and ir2104 gate drivers and these drivers are working fine also with no load. regarding the boot cap, depending on your total gate input cap of your mosfet you will choose the value for the boot cap. 100nF will be a prefered value. with such boot cap you will keep...
  14. P

    Preventing shifts in a weigh scale system

    Normally signal conditioners for load cell have thermal compensation. But if you want to build your own signal conditioner from discrete parts it will be a challenge for higher resolutions. I faced also the same problem some time ago when i built my own signal conditioner. Now i am considering...
  15. P

    Boot-strap components

    You can use also a charge pump to keep the bootstrap cap always charged even when no load is present
  16. P

    MOSFET current flow direction...

    mosfet current flow Yes, this is possible since the channel is on! As long Vgs > Vgs threshold the channel is on and the current can flow in both directions.
  17. P

    Noise on ADS1251 Vdd pin

    ads1251 Hi my friends, I built an A/D converter for load cell using ADS1251 from TI. At the beginning i had a lot of noise on Vdd supply pin (also on Vref and supply pins for signal amplifiers), but after manny hours spent in the lab i successfully removed some sources of noise. When you...
  18. P

    AD7730 Effective resolution

    ad7730 site:edaboard.com Hello my friends! I built an weight system based on ad7730 chip from analog devices! When i operate the chip at 200 hz in chop mode i obtaine an effective peak to peak resolution (no flicker code) of 14 bits in 10 mV unipolar ranges (with the inputs shorted in...
  19. P

    Noise induced by microcontrollers

    Unfortunately during ADC sleep mode the uart is not active, and is very important for my application that the device to respond to every command that it receive. I will check in the next days with different sleep modes to see if it's possible to solve this problem. Thank you
  20. P

    Noise induced by microcontrollers

    Thanks for the suggestion! It will be difficult to implement for my project (but not impossible) because during conversion the microcontroller should be able to receive commands from serial port. But it's really a good ideea! I will try to implement it! I am using microcontroller from Atmel and...

Part and Inventory Search