The ADC on the AVR's is nothing that's going to win any awards, but it's good enough for 99% of hobby electronics projects.ĪnalogRead() tells it to take a sample (using the S&H functionality) and start the conversion, twiddle it's thumbs until the ADC is done converting, and return the value it read.ĭepending on how your code is written, that will effect how often the ADC gets read, of course. I'm very new to Arduino's and electrical engineering principles, so please explain this on a simple level.ĪnalogRead() takes like 110us on a mega - see Microcontroller I/O & ADC Benchmarks - Microcontrollers - Arduino Forum for the time taken for analogRead() on various boards. What kind of technical specification would I look in case I do need to find a faster microcontroller? Is there a way to make the Arduino Mega internal clock run faster? Is the Arduino code limited such that it's sampling rate may vary depending on like how long/complicated the code is?
#ARDUINO MEGA 2560 MICROCONTROLLER HOW TO#
If it is not fast enough I think I would need to use a different microcontroller, but not sure what or how to find one with appropriate specifications. I was thinking maybe I can measure the time constant of my capacitive sensor, and then compare that to the internal clock sampling rate and see if the Arduino is fast enough. The idea I had was that maybe the timing is slightly off on the clock, and that means when I charge my capacitor plate with 5 V, it might be 4.99 or slightly off, which changes the time constant of the capacitor, and then when I measure the voltage of the opposite electrode, I get slightly different values, and when the capacitance is calculated, it's off - resulting in noisy data.
I looked there because another post said something similar.īackground on the problem: I have a problem where I'm trying to measure my capacitive sensor's capacitance, but I think the internal clock on the Arduino is too slow, because I get noisy data that looks like I'm measuring 3 signals worth of data instead of 1.
How do I find/what is the sampling rate of an Arduino Mega 2560's internal clock? I tried looking in the pathway: /Applications/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino/wiring.c file, but I don't understand the information in the file.
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