Hi Ytai, thank you for your help. The signal is the output of an A.C. current sensor, the frequency is the same as the network, 60 hz, and the sensor can measure up to 30 A with a sensitivity of 66 mV/A. The signal has always a D.C. value of 2.5 V so if i measure 1 A the signal will have a max of 2.566 V and a min of 2.434 V. The absolute maximum with 30 A is 4.48 V and absolute minimum of 0.52 V, so the signal is always in the range of the analog input of the ioio. I want to know the value rms of the current in my smartphone, and i tried obtaining the rms of the voltage by calculating the max value of a buffer of 1000 values and the multiplying it by 0.707. I get the value rms of the current with an accuracy of +-0.1 A, but i need it to be less than that, that's why i though it would be better to compute the rms value of the signal in hardware so i dont have to send the whole buffer of the signals.
El martes, 14 de julio de 2015, 18:44:30 (UTC-5), Ytai escribió: > > Before we begin, can you please specify the signal you're trying to > measure better? > Specifically, its min and max (instantaneous) voltage, and its bandwidth > would be important. > Based on that I can recommend a way of measuring it. > > On Tue, Jul 14, 2015 at 3:06 PM, Julio Castellanos <[email protected] > <javascript:>> wrote: > >> Hello, i'm currently working with the IOIO analog input with a sensor >> signal that comes out as an A.C. signal in the range of 2,5 V as mean >> value. I've tried to get the voltage through the analog input and get the >> rms value in software, but the value changes to much because of the >> bandwith limit of the IOIO:Android communication. I'm now looking to get >> the RMS directly in hardware and just send that value to the software but i >> gave a look at the hardware code for adc.c and i don't understand almost >> nothing, can someone point out to me a source where i can learn how does >> this code works? >> >> -- >> You received this message because you are subscribed to the Google Groups >> "ioio-users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected] >> <javascript:>. >> Visit this group at http://groups.google.com/group/ioio-users. >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "ioio-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/ioio-users. For more options, visit https://groups.google.com/d/optout.
