README
======
This directory contains the port of NuttX to the Adafruit Metro M4. The
Metro M4 uses a Arduino form factor and and pinout. It's powered with an
ATSAMD51J19:
o Cortex M4 core running at 120 MHz
o Hardware DSP and floating point support
o 512 KB flash, 192 KB RAM
o 32-bit, 3.3V logic and power
o Dual 1 MSPS DAC (A0 and A1)
o Dual 1 MSPS ADC (8 analog pins)
o 6 x hardware SERCOM (I2C, SPI or UART)
o 16 x PWM outputs
o Stereo I2S input/output with MCK pin
o 10-bit Parallel capture controller (for camera/video in)
o Built in crypto engines with AES (256 bit), true RNG, Pubkey controller
o 64 QFN
STATUS
======
2018-07-26: The basic port was merged into master. It is still
incomplete and untested. It is missing the clock configuration logic.
There is a placeholder from the SAML21, but it is currently stubbed out
in the Make.defs file. Configuration options in the board.h header
file are bogus and also just cloned from the SAML21.
2018-07-29: Clock configuration logic now complete. board.h
configuration options still need to be verified. Unverified SERCOM
USART, SPI, I2C, Port configuration, and DMA support have been added.
I still have no hardware in hand to test.
Serial Console
==============
An Arduino compatible serial Shield is assumed (or equivalently, and
external RS-232 or serial-to-USB adapter connected on Arduino pins D0 and
D1):
------ ----------------- -----------
SHIELD SAMD5E5 FUNCTION
------ ----------------- -----------
D0 PA23 SERCOM3 PAD2 RXD
D1 PA22 SERCOM3 PAD0 TXD
LEDs
====
The Adafruit Metro M4 has four LEDs, but only two are controllable by software:
1. The red LED on the Arduino D13 pin, and
2. A NeoPixel RGB LED.
Currently, only the red LED is supported.
------ ----------------- -----------
SHIELD SAMD5E5 FUNCTION
------ ----------------- -----------
D13 PA16 GPIO output
Configurations
==============
Each Adafruit Metro M4 configuration is maintained in a sub-directory and
can be selected as follow:
tools/configure.sh [OPTIONS] metro-m4/<subdir>
Do 'tools/configure.sh -h' for the list of options. If you are building
under Windows with Cygwin, you would need the -c option, for example.
Before building, make sure that the PATH environmental variable includes the
correct path to the directory than holds your toolchain binaries.
And then build NuttX by simply typing the following. At the conclusion of
the make, the nuttx binary will reside in an ELF file called, simply, nuttx.
make
The <subdir> that is provided above as an argument to the tools/configure.sh
must be is one of configurations listed in the following paragraph.
NOTES:
1. These configurations use the mconf-based configuration tool. To
change any of these configurations using that tool, you should:
a. Build and install the kconfig-mconf tool. See nuttx/README.txt
see additional README.txt files in the NuttX tools repository.
b. Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
2. Unless stated otherwise, all configurations generate console
output of on SERCOM3 which is available on a Arduino Serial
Shield (see the section "Serial Console" above).
3. Unless otherwise stated, the configurations are setup build under
Linux with a generic ARM EABI toolchain:
Configuration sub-directories
-----------------------------
nsh:
This configuration directory will built the NuttShell. See NOTES above.
