hi, i am developing a weigh scale application using Cirrus Logic 5532 24-bit ADC in unipolar mode.the output i am getting is very unstable (flickering on display). Can anybody please tell me how to get a stable count.
We use the same CS5532 for current measurement in battery management systems and I agree that its output might be very noisy. I use the upper 16 bits of the 24 bit AD-result and there's still noise. Noise depends on the hardware design (PCB Layout...). Don't use the same ground and supply for AD-converter and controller. The controller is very noisy, and that might also influence its supply. Before using software filtering (moving AVG), a hardware filter (i.e. anti aliasing filter) and perhaps a pre-amplifier (instrumention amplifier) is necessary.
Mine is a small budget project so i cannot invest in a DSP plus i have no prior experience in DSPs. 1) there is no need for a DSP 2) "limited budget" and "24bit ADC" - the joke of the year. You can NOT achieve anything above 14 bits without a 4 layer board, a chopper stabilized op-amp with expensive high precision resistors, a high precision voltage reference, an extremely quiet power supply ...... Erik
this is my first project ... Get an analog PCB layout book or you will never get anywhere with this. Erik
First of all i would like to tell u that the problem was with power line noise rejection. I had wrongly configured the ADC for 60Hz noise rejection(7.5Sps OWR) instead of 50Hz noise rejection and corresponding OWR of 6.25Sps.The display is now much stable(+-1 weight). this is my first project ... Get an analog PCB layout book or you will never get anywhere with this. This really is my first project. i am only developing the software for the project invloving the interfacing of the uc with the ADC, display, keyboard and AT24C02 eeprom in C using keil C51 tools and hence wanted to how if any coding could control the flickering. i was not part of the pcb desinging and layout process.
First of all i would like to tell u Why do you use the forum to tell micro something? now: The display is now much stable(+-1 weight). earlier: my display is flickering in +/- 7 counts range with occasional surges do you still have the "occasional surges"? Erik