CAN-FD Generic IO

dc42

I've added a SAMMYC21 build configuration to project Duet3Expansion. It's designed to work with the bootloader from chip45.com. I won't have a chance to test/debug it until the boards I have ordered arrive.

I've set up the pin table to use the available ports on the Sammy-C21 board as follows:

PA02 "temp0" (thermistor or other analog input)
PA03 "temp1" (thermistor or other analog input)
PA04 "pa04" input, output with PWM
PA05 "pa05" input, output
PA06 "pa06" input, output with PWM
PA07 "pa07" input, output
PA08 "pa08" output
PA09 External driver EN, active low
PA10 External driver DIR, active low
PA11 External driver STEP, active low
PA12 "pa12" input, output with PWM
PA13 "pa13" input, output
PA16 "pa16" input, output
PA17 "pa17" input, output
PA18 "pa18" input, output
PA19 "pa19" input, output with PWM
PA20 "pa20" output
PA21 "pa21" output
PA22 "pa22" output
PA23 "pa23" output with PWM
PB08 "pb08" input, output
PB09 "pb09" input, output

A Former User

@dc42 said in CAN-FD Generic IO:

I've added a SAMMYC21 build configuration to project Duet3Expansion.

much love!

drobertson123

@dc42 That is great.

I got in some components to play with, not the SAMMYC21 yet, but some CAN-FD compliant transceivers and some NUCLEO STM32 boards that have built-in CAN-FD.

When my SAMMYC21 gets here I should have a decent ecosystem of boards.

When is the CAN-FD Stepper driver you had mentioned earlier estimated to be available? Will it have some IO for endstops? If so it would be a good fit for driving my Delta arms.

I already have the tool board on order(looking forward to filastruder shipping it) and I think I am picking up a second Duet 3 Mainboard for a CoreXY project. I like where you are taking your products. Keep it up.

mwwhited

@dc42 said in CAN-FD Generic IO:

A disadvantage is that a license fee is payable on any EtherCAT device, although not on on an EtherCAT host

As stated in their own FAQ

3.3 How about licences? 
There is a licence for implementing an EtherCAT master which is free of charge - the agreement demands compatibility, ensures that the licence remains free of charge and provides legal certainty. For slave devices EtherCAT has adopted the CAN license model (CAN is an excellent example for a standardized open technology that is protected by patents): The small license fee is "embedded" in the EtherCAT Slave Controller (ESC) chip, so that device manufacturers, end users, system integrators, tool manufacturers etc. do not have to pay a license.

This license is only payable for dedicated embedded controllers. If you used a multi-master configuration there would be no dedicated chip and no payable license. If you did use an embedded chip the license free is included with the chip cost.

JoergS5

I ordered the sammy also, it is available through eb.. and is a nice small device.

If someone is interested in FPGAs, I detected an open source CAN-FD VHDL implementation of CAN-FD on https://gitlab.fel.cvut.cz/canbus/ctucanfd_ip_core
(but according to their readme one needs a license from Bosch for commercial usage)

drobertson123

@JoergS5 said in CAN-FD Generic IO:

I ordered the sammy also, it is available through eb..

What is eb? Is it a source in the US?

The SAMMYC21 is great but the shipping to the US doubles the price. I am hoping that someone here stocks them so we can get them at a more reasonable price.

JoergS5

@drobertson123 sorry to abbreviate... eb=ebay, germany in my case. chip45 offers his products in ebay for the same price as in his supplier shop.

wilriker

@JoergS5 Just to mention that: chip45 is a German company.

JoergS5

@wilriker I wonder why the don't offer in digikey.com, because e.g. Trimac TMC chip are german also, but offer worldwide. That's a pity for non-europe users.

dc42

If there is enough interest in it in the US, perhaps Filastruder may be interested in stocking them?

drobertson123

Having filastruder stock them would be good.

I am ok with paying a bit of a premium but it doubles the price for the board to order it from the US. At that price point, I am looking at more local solutions despite the SAMMYC21 board looking good. I still have one coming to test but I am also playing with the STM Nucleo boards that I can get local for $15, add on the transceiver for $2 and I have a good base to work with.

dc42

I have the Sammy-C21 board working with Duet 3 now and the firmware is committed to Github (there are now SAMMYC21 build configurations in the Duet3Bootloader and Duet3Expansion projects). I will write a wiki page soon on how to use it with Duet 3.

dc42

The wiki page is now available here https://duet3d.dozuki.com/Wiki/Using_the_Sammy-C21_development_board_with_Duet_3.

A Former User

The Sammy-C21 can be purchased directly from chip45.com. We are making arrangements with them to have the Duet3D CAN bootloader pre-installed as an option.

.. not sure why I keep being amazed by you guys, but I do ..

(edit: it should be possible to use OpenOCD and RaspberryPi GPIO to flash the Atmel chip over SWD, might pick up one of those boards next month and give it a try, providing an alternative to pricey Atmel ICE)

JoergS5

For Arduino based solutions there is CANdiy-shield, an Arduino library is available for it. The shield can switch 3.3 and 5v. There are two versions of the shield, v2 and fd, the fd version has CAN-FD.

hauschka

CANdiy shield seems very interesting.

Would anyone have an idea what sort of message I'd have to send?

I'm imagining a scenario where I place a Gcode-command in my code and my Arduino is then "noticed" via CAN-FD to run a function

Vice-versa, the Duet would "wait" until it receives a notification via CAN-FD .

Would this even be remotely possible or am I completely off in terms of capabilites of CAN-FD?

For example, to come back to the Sammy-C21 documentation, how would I go about setting a pin high/low or querying the status of a pin through Gcode?

ChrisP

My Sammy-C21 and Atmel-ICE arrived today and after some fiddling I've managed to get the latest version of the Duet3Expansion firmware built and flashed using OpenOCD through Eclipse. However, I'm curious to know if others who are using the Atmel-ICE are using it with Eclipse and whether they've managed to get it working properly as a debugger with breakpoints etc?
I'm pretty sure it's flashed fine as I have the rapid flashing light indicating no CAN connection (I need to go and dig out some RJ11 to hook it up to the Duet3 to be sure), but having the ability to debug properly would be nice.

dc42

So far I have only used the Atmel ICE in Atmel Studio, by loading the .elf file produced by Eclipse. Debugging is rather limited. You can set breakpoints, but not read the values of variables without working out their memory addresses first.

ChrisP

Yeh, using the Atmel-ICE with Atmel Studio to program the .elf from Eclipse was super simple, it just seemed a bit overkill and I wondered if I was missing something. I can set breakpoints in Eclipse but they're not handled properly and while execution is halted and can be resumed, as you say variables can't be read.
Nevermind, it's useful as is anyway. I shall get on to getting it hooked up to the Duet and hope I don't need to do too much debugging