https://forge.codesys.com/forge/talk/Runtime/thread/80ca780e26/2021-08-20T06:30:45.837000ZRecent posts to Why Use SPI Drivers?2021-08-20T06:30:45.837000Z2021-08-20T06:30:45.837000Zojz0rhttps://forge.codesys.com/u/ojz0r/https://forge.codesys.comb2bfa6d3171acbdaec73bd55e7597365672dbe25

<div class="markdown_content"><p>XML file + Library would be one way if you want to hard code a driver.</p> <p>Otherwise you can do it in logic using the method "SPI_master.transferExt(...)". Then you can define what you want to send and receive at runtime.<br/> For example, the messages sent/received will be different for the MCP23017 (Microchip 16xGPIO chip) and MCP3208 (Microchip 8xADC inputs).<br/> Look at the example project "PiFace_FB.project" to see how it is used. It is very flexible.</p></div>

2021-08-19T22:23:54.443000Z2021-08-19T22:23:54.443000Zbwaythttps://forge.codesys.com/u/bwayt/https://forge.codesys.com39f3bba08dba0b5ede20532b13d474a906a9236f

<div class="markdown_content"><p>Yeah, both using the same SPI driver sounds right: I'm sure when you state your device that Codesys makes certain assumptions about how comm protocols will be handled.<br/> By "soft drivers", do you mean drivers specified through an XML file + Library? <br/> I'm still not sure as to why we use such roundabout methods when RPI4 has its own SPI library to use; not like the buffer board has anything special about the way it sends its bytes.</p></div>

2021-08-19T18:41:52.476000Z2021-08-19T18:41:52.476000Zojz0rhttps://forge.codesys.com/u/ojz0r/https://forge.codesys.com45331ca019d08606f2cd4d8b7558f7d3dd1d89bf

<div class="markdown_content"><p>I might be wrong but i am fairly sure codesys is leveraging the same low level linux spi driver as the python library does.<br/> A driver for codesys would be equal to the library for python.</p> <p>However there are very flexible drivers that lets you define the protocol yourself to write "soft" drivers in plc code and then feed it to a function.</p></div>

2021-08-19T16:09:03.662000Z2021-08-19T16:09:03.662000Zbwaythttps://forge.codesys.com/u/bwayt/https://forge.codesys.com51b7c372d7ab3ded0d2d9b43677deff63feaacba

<div class="markdown_content"><p>A bit of background: I have a LS7366R buffer board (Link: <a href="https://lsicsi.com/datasheets/LS7366R.pdf" rel="nofollow">https://lsicsi.com/datasheets/LS7366R.pdf</a>) that I have successfully established SPI connection with on Arduino and Raspberry Pi 4B (via Python's spidev library). <br/> I am now trying to establish the same SPI comm via Codesys, but noticed that you must have a SPI device driver for your slave (there's posts about writing your own device drivers, but I feel out of my depth in that regard). <br/> My question is: <em>why</em> do I need to specify a driver for this SPI device? What did spidev handle that Codesys' SPI doesn't?<br/> And: if I can't write my own driver, what other options do I have?</p></div>