Support for Acorn Econet protocols on the Raspberry Pi Pico
Hardware currently comprises simply the classic Econet circuit connected to pins on the Pico rather than a 6854 - the magic is in the Pico PIO rather than the circuit.
Pin choice is relatively unimportant as the software takes a pin list on startup, though it's highly desirable for CLK_IN to be on an odd-numbered GPIO pin so that a PWM 'B' channel can be used to measure clock speed.
Software has notional support for more than one Econet interface on the Pico, (eg to allow it to be an Econet bridge) though not yet fully developed.
Current hardware has CLK_IN and CLK_OUT on different pins: they could sensibly share a pin on pin-constrained designs.
New: code is now structured to build for multiple different platforms, parameterised by a board file - in the boards/ subdirectory here. These are derivitives of the boards/pico.h that comes with the pico SDK - for hardware using an actual pico, you can just define how econet is wired up and then #include <boards/pico.h>. For custom boards that may be more or less similar to a Pico, define everything in a new board file. There are examples of both in there now.
Install the pico-sdk somewhere and set PICO_SDK_PATH to point at it.
git clone -b master https://github.com/raspberrypi/pico-sdk.git
cd pico-sdk
git submodule update --init
setenv PICO_SDK_PATH `pwd`
Fetch this repository:
git clone https://github.com/arg08/picoeco.git
Build one of the projects within it:
cd picoeco/ecotest
mkdir build
cd build
cmake .. -DPICO_BOARD=eco_skt_box
make
(similarly for picoeco/netmon etc) This generates a binary ecotest.uf2
Get the pico into boot mode by powering up with the button on the pico held (or hold down the button on the pico and press the reset button).
Either mount the pico as if it were a USB memory stick and copy the .uf2 file onto it, or else build picotool and use:
picotool load netmon.uf2 -x
Standard Pi documentation covers Linux: https://datasheets.raspberrypi.org/pico/getting-started-with-pico.pdf
To build on a FreeBSD PC host, you need the following packages installed:
cmake pkgconf gcc-arm-embedded (NB. not arm-none-eabi-gcc, it doesn't work!) git
You then need to set PICO_TOOLCHAIN_PATH=/usr/local/gcc-arm-embedded as well as PICO_SDK_PATH
I find picotool more useful than the USB mass storage stuff; it now builds per the Linux instructions (earlier versions needed a tiny patch, but this has now been incorporated upstream).
git clone -b master https://github.com/raspberrypi/picotool.git
NB. FreeBSD has libusb in the base system rather than a package.