ich muss für dir Uni ein Projekt machen und stecke an einer Sache fest.
Ich kriege es langsam hin, dass der Raspberry über einen AD Wandler Audiosignale aufnimmt.
Jedoch ist die Darstellung (siehe Bild) nicht wirklich übersichtlich..
microphone.py
Code: Alles auswählen
import time
import botbook_mcp3002 as mcp
def readSound(samples):
buff = []
for i in range(samples):
buff.append(mcp.readAnalog())
return buff
def main():
while True:
sound = readSound(1023)
print(sound)
time.sleep(0.5) # s
if __name__ == "__main__":
main()botbook_mcp3002 library:
Code: Alles auswählen
import spidev # installation help in botbook_mcp3002.py comments
import time
def readAnalog(device = 0,channel = 0):
assert device in (1, 0)
assert channel in (1, 0)
#open spi
spi = spidev.SpiDev()
spi.open(0, device)
"""
Protocol start bit (S), sql/diff (D), odd/sign (C), MSBF (M)
Use leading zero for more stable clock cycle
0000 000S DCM0 0000 0000 0000
Sending 3 8bit packages so xpi.xfer2 will return the same amount.
start bit = 1
sql/diff = 1 SINGLE ENDED MODE (2 channel mode)
odd/sign = channel 0/1
MSBF = 0
"""
command = [1, (2 + channel) << 6, 0]
#2 + channel shifted 6 to left
#10 or 11 << 6 = 1000 0000 or 1100 0000
reply = spi.xfer2(command)
"""
Parse right bits from 24 bit package (3*8bit)
We need only data from last 2 bytes.
And there we can discard last two bits to get 10 bit value
as MCP3002 resolution is 10bits
Discard reply[0] byte and start from reply[1] where our data starts
"""
value = reply[1] & 31
#31 = 0001 1111 with & operation makes sure that we have all data from XXXX DDDD and nothing more. 0001 is for signed in next operation.
value = value << 6 #Move to left to make room for next piece of data.
#000D DDDD << 6 = 0DDD DD00 0000
#Now we get the last of data from reply[2]
value = value + (reply[2] >> 2)
#Here we discard last to bits
#DDDD DDXXX >> 2 = 00DD DDDD
#0DDD DD00 0000 + 00DD DDDD = 0DDD DDDD DDDD
spi.close()
return value
def main():
#read channel 0 on device 0
value = readAnalog(0, 0)
print value
time.sleep(10)
if __name__ == "__main__":
main()Ich danke euch
