Much as I like LinuxCNC, Mesa cards, and even Arduino's occasionally, I'd go straight to AutomationDirect and get an inexpensive PLC for this job. It would already handle all the 24v I/O, have a very clean and complete ladder logic, with good state machine methods.
-- Ralph ________________________________________ From: Sven Wesley [svenne.d...@gmail.com] Sent: Tuesday, September 15, 2015 6:12 AM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] A lot of input/output. Cheap 2015-09-15 14:16 GMT+02:00 andy pugh <bodge...@gmail.com>: > On 15 September 2015 at 13:03, Carsten Presser <c...@rstenpresser.de> wrote: > > > the big advantage of the mesa-boards is that they are well suited to > > drive relays and other kinds of devices. > > An Arduino or similar board only has TTL or CMOS IOs which need to get > > adapted to your actual IO voltages/currents. > > Also, thinking about it, an Aduino Mega is no cheaper than a 7i90 > > http://store.mesanet.com/index.php?route=product/product&filter_name=7i90&product_id=291 > That has the same IO voltage problems as the Arduino, but plugs > straight in to LinuxCNC (EPP Parport) and realtime HAL. > http://linuxcnc.org/docs/html/man/man9/hm2_7i90.9.html > > Don't get me wrong, I like Mesa. A Mesa board is not cheaper than a Mega. You can order a clone on eBay for less <http://www.ebay.co.uk/itm/New-ATmega2560-16AU-Improved-version-CH340G-MEGA2560-R3-Board-For-Arduino-SWTG-/231616834408?hash=item35ed706b68> than half. I have a few of those and they work as expected. There are Arduino relay boards out there as well. I will get all the relays needed <http://www.ebay.co.uk/itm/New-8-Channel-5V-Relay-Module-Board-for-Arduino-PIC-AVR-MCU-DSP-ARM-UK-/151105724470> and the Arduino board, still for less money than one 7i90. But I prefer opto isolated heavy duty solid state relays for this instead of tiny mechanical relays on a small board. You should see the relay panel inside the machine, the relays are like bricks... I think your suggestion with the HAL/Arduino library will be the cheapest possible and more than good for this application, I will try it for sure! With some small tweaks it will be fine for a Mega board and I should have enough I/O. Thanks! /S ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
