Hey guys,
I am thinking this might be a trivial question, but wanted to double check to make sure I am going about this correctly. I found this schematic online a while back and decided to use it. I'm sure there are probably some improvements that could be made. Here is my version of it in eagle:
I took oscilloscope readings right up next to the analog-to-digital converter chip (ADC) and there are very steady/even spikes about 1.55 volts in amplitude, and between 1.6 - 1.7 kHz. Up to this point I have just been taking multiple readings via the ADC chip, then averaging them together to get the average voltage value. This has been working out well, but I would like to filter these spikes out before sending it into the ADC chip - mainly because once the spikes go over 3.3 volts it starts to change the curve since 3.3 volts is the cutoff for the ADC.
What is the best way to turn these spikes into a nice steady voltage reading for the ADC? Would I just do a low pass RC circuit? I used this online filter calculator:
http://www.ekswai.com/en_lowpass.htm
I put in 1uF for capacitor, 120 ohms for resistor, and it gives me 1.33 kHz, so this means anything of higher frequency will not get through correct?
Although... will this just smooth the signal out to the bottom of the oscillation and not give me the average voltage value?
I am thinking this might be a trivial question, but wanted to double check to make sure I am going about this correctly. I found this schematic online a while back and decided to use it. I'm sure there are probably some improvements that could be made. Here is my version of it in eagle:
I took oscilloscope readings right up next to the analog-to-digital converter chip (ADC) and there are very steady/even spikes about 1.55 volts in amplitude, and between 1.6 - 1.7 kHz. Up to this point I have just been taking multiple readings via the ADC chip, then averaging them together to get the average voltage value. This has been working out well, but I would like to filter these spikes out before sending it into the ADC chip - mainly because once the spikes go over 3.3 volts it starts to change the curve since 3.3 volts is the cutoff for the ADC.
What is the best way to turn these spikes into a nice steady voltage reading for the ADC? Would I just do a low pass RC circuit? I used this online filter calculator:
http://www.ekswai.com/en_lowpass.htm
I put in 1uF for capacitor, 120 ohms for resistor, and it gives me 1.33 kHz, so this means anything of higher frequency will not get through correct?
Although... will this just smooth the signal out to the bottom of the oscillation and not give me the average voltage value?