how get the value in uV...
Hi everybody, i'm having some problems to undestand the value that the board send to pc, i explain.
I'm working in python, and i wrote this while loop statement, to read what the board serd:
I'm working in python, and i wrote this while loop statement, to read what the board serd:
while True:
pacchetto = [] #this is an array of integer that rapresent a packet
canale_1 = [] #another array where i put the conversion byte in integer that rapresent the channel 1
fine = scheda.read() # in this the line of code i manage the sincronism between the board an the pc
inizio = scheda.read()# in this the line of code i manage the sincronism between the board an the pc
if ord(fine) == 192 and ord(inizio) == 160: # start byte and closer byte of the packet
for c in range(0,31): # read all the byte that compose a packet
valore = scheda.read()
pacchetto.append(ord(valore)) # in pacchetto[] i put integer
canale_1 = [pacchetto[1], pacchetto[2], pacchetto[3]] # as sad in the guide the byte 3 4 and 5 is refered to channel 1
print canale_1
valore = conversione(pacchetto[1], pacchetto[2], pacchetto[3]) #simple function that convert an array of integer in one value
print valore
def conversione (primo, secondo, terzo):
intero_senza_segno = (primo*pow(2,16)) + (secondo*pow(2,8)) + terzo
if primo >= 127: #in this if - else statement i manage the sign of the value
intero_con_segno = intero_senza_segno - pow(2,24)
return intero_con_segno*fattore_di_scala # fattore di scala = 0.02235
else:
return intero_senza_segno*fattore_di_scala # fattore di scala = 0.02235
my output is this:
[152, 198, 207]
-453618.52838
[233, 72, 30]
-99836.2570806
[152, 199, 14]
-453614.303901
[231, 255, 216]
-105471.444782
[152, 198, 44]
-453629.458383
[233, 145, 128]
-98576.5574666
[152, 199, 200]
-453601.831627
[232, 70, 109]
-104259.823771
[152, 199, 99]
-453608.604206
[232, 216, 79]
-101755.579025
the array is the byte of channel and the float is the value in uV... in theory...
The question... what i'm doing wrong... i try the famous user.py, but this code give me an error infact the code can't decode the start byte or the ending byte... so i decide to write my self the code...
thx for your time to read this, and thx for the replies
thx for your time to read this, and thx for the replies
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