Arduino Fio- Analogic Inputs
hello know if can connect analog input 5v signal , maximun voltage analog input.
this question because arduino fio works 3.3 v
thanks!!!
this question because arduino fio works 3.3 v
thanks!!!
max signal 0.5v above vcc.
so 5v no-no on 3.3v powered part.
take signal , divide in half 2 10k resistors:
signal - resistor r1 - arduino pin - resistor r2 - gnd.
or select resistors signal remains below 3.3v
vout = vin * r2/(r1 + r2)
3.3v = 5v * (10,000)/(r1 + 10,000)
3.3v * r1 + 3.3v*10,000 = 5v * 10,000
3.3v * r1 = (50,000 - 33,000)
r1 = 17,000/3.3 = 5.15k
so use 10k & 5.7k:
5v*10,000/(10,000 + 5700) = 3.185v
so 5v no-no on 3.3v powered part.
take signal , divide in half 2 10k resistors:
signal - resistor r1 - arduino pin - resistor r2 - gnd.
or select resistors signal remains below 3.3v
vout = vin * r2/(r1 + r2)
3.3v = 5v * (10,000)/(r1 + 10,000)
3.3v * r1 + 3.3v*10,000 = 5v * 10,000
3.3v * r1 = (50,000 - 33,000)
r1 = 17,000/3.3 = 5.15k
so use 10k & 5.7k:
5v*10,000/(10,000 + 5700) = 3.185v
Arduino Forum > Using Arduino > Installation & Troubleshooting > Arduino Fio- Analogic Inputs
arduino
Comments
Post a Comment