I2C readfrom_mem - can't convert bytearray to int

[devnull]

I seem to be unable to get past this error:

Code: Select all

import machine as mc
import ustruct
timebuf = bytearray(7)
i2c = mc.I2C(scl=mc.Pin(5), sda=mc.Pin(4), freq=100000)
ustruct.unpack("<h", i2c.readfrom_mem(104,timebuf,0))[0]

>> TypeError: can't convert bytearray to int

Any idea why ustruct is unable to convert the data to an integer ?

[dhylands]

According to the docs:
http://docs.micropython.org/en/latest/p ... adfrom_mem

The second argument is supposed to be an int and you're passing in timebuf (which is a bytearray). readfrom_mem doesn't even take a bytearray as an argument. readfrom_mem_into takes a buf argument, but its the 3rd argument, not the second.

[devnull]

Thanks dave, but that link is for pyboard mem_read() and I am using the standard readfrom_mem() on esp8266 device.

[dhylands]

The docs for the esp8266 look to be the same to me:
http://docs.micropython.org/en/latest/e ... adfrom_mem

[devnull]

Code: Select all

readfrom_mem(addr, memaddr, nbytes, *, addrsize=8)

I think the 3rd param (nbytes) is number of bytes, but I am now looking at readfrom_mem_into() which does support a bytearray()