INTL 3:770/1 3:770/3   
   REPLYADDR 56g.1183@ztq4.net   
   REPLYTO 3:770/3.0 UUCP   
   MSGID:  6eff3832   
   REPLY:  03eb74c6   
   PID: SoupGate-Win32 v1.05   
   On 1/3/24 7:15 AM, Theo wrote:   
   > 56g.1183 <56g.1183@ztq4.net> wrote:   
   >>     In My Experience - MOST USB/SERIAL adapters work OK   
   >>     in PI/OS. I think, despite brand names, there are only   
   >>     a few actual chip-sets.   
   >>   
   >>     While Amazon reviews are a bit suspect, still DO   
   >>     read them, with particular attention to Linux   
   >>     remarks   
   >   
   > If you can find the chip number, that's the main thing.  If there is a link   
   > to Windows drivers, downloading them and taking a look at the .inf file is a   
   > good clue.   
   >   
   >>     IF you get stuck having to load virtual Winders   
   >>     drivers ... then you haven't chosen wisely   
   >   
   > There is no support for running virtual Windows serial drivers in Linux.   
   >   
   >>     Pi's can also do RS-232 directly. A bit less civil,   
   >>     but it works.   
   >   
   > Pis can do *serial* directly, but not RS232.  They only have 3.3V signal   
   > levels, so voltage conversion needed for RS232 or another voltage (1.8V, 5V,   
   > etc).   
      
      Yep ... level-shifting chips are generally needed.   
      The MAX3232 will do it.   
      
      
   https://www.analog.com/media/en/technical-documentation/data-she   
   ts/MAX3222-MAX3241.pdf   
      
      If you are talking to VERY old serial devices that still   
      expect some plus/minus 12v or more signals then you may   
      have to double-up, add a MAX232 after the 3232   
      
      3.x volts IS a pain in the ass. Eventually all the old   
      devices will be gone and the new stuff will do 3.x or   
      less. However, there are still a lot of those "old devices"   
      still out there and still in profitable use and likely   
      will be for at least another 25 years.   
      
      As for converters ... I'd swear I got a USB<->232   
      unit working on a Pi3 ... but don't quote me on it.   
      I'm kinda a hardware guy, so I would have made   
      something with the MAX chips almost automatically.   
      
      Anyhow, peruse the usual spots, AdaFruit, SparkFun,   
      Seeed. They may have a canned solution.   
      
   --- SoupGate-Win32 v1.05   
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