This is consistent with the other 'micro' modules and allows implementing
additional features in Python via e.g. micropython-lib's sys.
Note this is a breaking change (not backwards compatible) for ports which
do not enable weak links, as "import sys" must now be replaced with
"import usys".
These addresses were initially chosen to match the nRF24 Arduino library
examples but they are byte-reversed. So change them to be on-air
compatible with the Arduino library.
Also, the data sheet for the nRF24 says that RX data pipes 1-5 must share
the same top 32-bits, and must differ only in the LSbyte. The addresses
used here (while correct because they are on TX pipe and RX pipe 0) are
misleading in this sense, because it looks like they were chosen to share
the top 32-bits per the datasheet.
Changes made are:
- Use the time module in place of the pyb module for delays.
- Use spi.read/spi.write instead of spi.send/spi.receive.
- Drop some non-portable parameters to spi and pin initialization.
Thanks to @deshipu for the original patch.
