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.