Micropython Controller for testing Oldwyk

Building the Toolchain

First download the submodules by typing

$ git submodule update --init --recursive

then build the freedom-e-sdk by

$ make tools

If you have the freedom-e-sdk already installed, you can skip the steps above, but you need to set the environment variable FREEDOM_E for all steps below.

Building the Micropython Firmware

Simply type

$ make firmware

Before uploading the firmware check chapter 5 of the Getting Started Guide and check whether you can connect to the Hifive1. If you verified that you can upload programs, then you can simply type:

$ make upload

Micropython console

You can connect to the micropython REPL using screen:

screen /dev/ttyUSB1 115200

You should see a message like:

core freq at 285523968 Hz
MicroPython v1.9.3-776-g5d35f272-dirty on 2019-12-10; Arty FPGA Dev Kit with E310
Type "help()" for more information.
>>>

If not, press the reset button on the board or type make upload again. To interact with Oldwyk first import the python board library (pyb) by typing on the REPL:

>>> import pyb

then create an SPI interface using a CS pin 7 (if you selected another pin during wiring, replace the 7 with that pin) and a maximum SPI frequency of 25 Mhz.

>>> spi = pyb.SPI(7, 2500000, 0, 0)

Now you can toggle the LED:

>>> spi.write_mem(0x1A101000, (1 << 10))
>>> spi.write_mem(0x1A101008, (1 << 10))
>>> spi.write_mem(0x1A101008, 0)

Upload micropython scripts

If you don't want to type all commands repeatedly on the REPL you can upload them using the upload.py script. For example, to do the locking sequence simple type

$ ./upload.py < examples/lmx_lock.py

Internals

You can find the internal of the python object [here] (https://github.com/bkoppelmann/micropython/tree/b0d8c69e8fa030aa05168c5b6f820bab321caf6f/ports/arty)

• [SPI] (https://github.com/bkoppelmann/micropython/blob/b0d8c69e8fa030aa05168c5b6f820bab321caf6f/ports/arty/modpybspi.c)
• PULPINO