LinuxCNC-RIO - RealtimeIO for LinuxCNC based on FPGA (ICE40 / ECP5)

From memory the TXS level shifters are not really designed for driving a cable of any length, ie they are more for component to component on the same board.
The fet bus switches I use with pull-up resistors on the high side will easily drive a generic breakout board on the end of a 1.8m Parallel Port cable. TBH I copied this method from the Mesa 7i92 or 7c81 schematics, so I don’t claim any originality just can confirm that it is reliable. The only issue being that a buffer is required to drive any load, but 99% of breakout boards use them anyways.
On the other hand if you want to set 8 pins aside for dedicated inputs that are 5v tolerant via a 3.3v device a 74lvc245 is the part you want.

ok, but i have to look what is available for a good price,
now i have ordered parts for ~14 Euro at aliexpress, ( >= 4 boards)

3.5 Euro / Board + 2 Euro PCB + 18 Euro TangNano9K + 8 Euro 5xBOB + .....

<35 Eruo for 5 or <43 Eruo for 10 axis

sounds too good, but will see

EDIT: ok, forgett the W5500   + 4Euro


 

meister wrote:

W5500
Level-Shifter (TXS0108E)
RGB-LED
Modbus
I2C - 5V (hope this will work via the level-shifter)

Maybe a good and cheap universal-board

That's just awesome!! Never thought of using the w5500 lite module as a board add-on, great idea. That would have simplified a whole lot. In the other board gossips, here's another fully functional/tested Gowin based RIO Motion Control Board. Surprisingly everything works flawlessly and so I'm upgrading this from a prototype rev 1.0 to alpha, and getting ready to start on a beta release (revision 1.1). Should be out and avail for testing in a week. 


 

damn mec, that was fast. but yeah i would look at the little W5500 lite modules, unless you got the whole w5500 part cheaper than $4. saves a bunch of space, but you can also make it as an optional add on. they seem like a pretty consistent part, ive bought around 40-50 so far from a few vendors so I could check how repeatable they are across lots

meister wrote:

ok, but i have to look what is available for a good price,
now i have ordered parts for ~14 Euro at aliexpress, ( >= 4 boards)
3.5 Euro / Board + 2 Euro PCB + 18 Euro TangNano9K + 8 Euro 5xBOB + .....
<35 Eruo for 5 or <43 Eruo for 10 axis
sounds too good, but will see
EDIT: ok, forgett the W5500   + 4Euro

damn i will need to send you some links to where ive been getting my stuff. i think you can get it down to 2.5-3 euro per w5500, and probably 4 euro for the bob. individual quantities arent much difference, but when you buy 10-20 at a time it adds up.

i prefer to calculate a little more and then also incl. fast shipping and small quantities


EDIT:
I should also say that this is just a hobby, I have no intention of marketing the boards.

if someone in DE (or maybe EU) wants one, i can send it at cost price, i just can never order a single one.

AliExpress is pretty cheap ATM for the W5500 boards, the blue ones with yellow connector. I think I’ve seen the little square ones for about $4-5 AUD, which equates to 2-3 magic beans.

I know it is weird, no trouble buying dev boards and such from AliExpress but when it comes to individual components Digikey or Mouser is my go to if my local electronics place doesn’t have them. I’ve given up on Element14/Farnells an RS as delivery times are just crazy to Oz. Digikey is great, free delivery over $60 AUD and delivery even when ordered on a Friday night or weekend is quick. Usually ask a mate if they need any bits so to keep what I actually have spend down a bit.
With regards to sending PCBs overseas, I’ve generally found the postage from Oz to be about the same what it would cost someone in their home country to order directly from the likes of pcbway or jlcpcb. So I just hand over gerbers.
Sometimes the world seems a bit silly.

Strange, the parts I ordered on Sunday night from Element 14 arrived on Thursday with DHL ex UK. No wonder they don't hold stock here anymore.

I gave up on them after they cancelled my last order with no reason given. Wasn't worth pursuing.
I'd use RS & Element14 more often if they didn't take forever, both of their warehouses are within 20 minutes of where I live. Even still, Digikey or Mouser are quicker.
THB I haven't used either in 2 years as I just got fed up with them.

hopefully tonight i will know if they work
 

one error on the board, but with a little fix, all works fine