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Trouble reading period register on ADE7753

Question asked by scottn40 on Apr 13, 2016
Latest reply on Apr 18, 2016 by scottn40

hello,

I am using a raspberry pi to read the period from the ADE7753 (register 0x27) in python. I am having trouble, i get an output but do not know how to convert it to the right frequency. any help would be appreciated. below is my code and the output:

 

---code---

 

import time

import spidev

import sys

 

spi = spidev.SpiDev()

spi.open(0,0)

spi.max_speed_hz = 62500

spi.mode = 0b01

 

if len(sys.argv) > 1:

    register = int(sys.argv[1], 16)

else:

    register = 0x27

 

result = spi.xfer2([register, 0x00, 0x00, 0x00])[1:]

print "reading register {}:".format(hex(register))

print [bin(x) for x in result]

print [hex(x) for x in result]

print result[0]

print result[1]

print result[2]

 

period = 256*result[1]+result[2]

period = period * 1.0

print "period" ,period

freq = 1 / period

print "freqeuncy", freq

print "done"

 

spi.close()

 

---result---

 

reading register 0x27:                                                                                                                                            

['0b11101', '0b110000', '0b0']                                                                                                                                    

['0x1d', '0x30', '0x0']                                                                                                                                           

29                                                                                                                                                                

48                                                                                                                                                                

0                                                                                                                                                                 

period 12288.0                                                                                                                                                    

freqeuncy 8.13802083333e-05                                                                                                                                       

done        

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