Random number generator

[timeb]

I had this idea of creating a finite state machine which makes transitions between three states. So, I needed to generate random numbers between 0 and 1. Is there such module for LoPy. I used randint(0,1) but it doesn't work. Any suggestions?

[livius]

@timeb
you can try something like this
https://docs.pycom.io/pycom_esp32/library/ucrypto.html?highlight=getrandbits#ucrypto.crypto.getrandbits

please be patient that i write this from memory without any test - you should fix errors
this is only concept

def Random():
   r = crypto.getrandbits(32)
   return ((r[0]<<24)+(r[1]<<16)+(r[2]<<8)+r[3])/4294967295.0

[livius]

i see that code work on my Wipy2 without any modification :)
below results

Random()
0.8462145
>>> Random()
0.4143322
>>> Random()
0.1052132
>>> Random()
0.7745724
>>> Random()
0.4098172
>>> Random()
0.2059813
>>> Random()
0.3866896

and bigger test:

sum=0
>>> ile=0
>>> for i in range(1,1000000):
...     sum+=Random()
...     ile+=1
...
>>> sum
499948.5
>>> ile
999999
>>> sum/ile
0.499949

realy near to 0.5 - as you can see it is ok :)

[timeb]

@livius Thanks I tried it and it works. I had another question if you could give some suggestion. I have been trying to take the last four bytes of the mac address as source and destination address to send data from one Lopy to a second LoPy. I created a package header as the following:

_LORA_PKG_FORMAT = "LL%ds"
_LORA_ACK_FORMAT = "LLB"
SRC_MAC_ADDR = ubinascii.hexlify(lora.mac().strip()[-4:])

Destination address
DEST_MAC_ADDR = b'9cc15603'

** pkg = struct.pack(_LORA_PKG_FORMAT, DEST_MAC_ADDR, SRC_MAC_ADDR, msg)

But when I try running it complains saying ValueError: unsupported format for the line with **. what do you think I am doing wrong?