Then the controller waits for the overflow flag to be set. First the timer overflow flag is set to zero. Timer2 is used to read the values at regular intervals. At a sampling rate of 77 kHz, the memory of arduino will be full very rapidly. An 8 bit number can be stored in a byte, a 10 bit number will take an integer (2 bytes). This reduces noise and allows for much more compact storage. ![]() Instead of 10-bit, only the 8 most significant bits are read. If the reading frequency is faster than 77kHz, the same value will be reported multiple times.Īdvantage of this approach is that no interrupt is needed (most sketches that I found so far wait for the analog read to get a new fresh result and will then read that value). This ADCH register may then be read at any desired frequency. ![]() This small program shows that Arduino UNO is capable of recording analog readings at a rate of at least 77 kHz (maybe even 154 kHz).įirst, the analog digital converter setup registers (ADSCRA and ADSCRB) are set in such a way that analog values will be read and put in the ADCH register continuously at a rate of 77 kHz.
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