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   PID: SoupGate-Win32 v1.05   
   On 2024-01-04, 56g.1183 <56g.1183@ztq4.net> wrote:   
   >>   
   >> 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.   
      
   It does more than "level shift" it also inverts the signals. It will   
   accept 3v or 5v logic, even though supplied from a 3.3v supply.   
      
   >   
   > https://www.analog.com/media/en/technical-documentation/data-s   
   eets/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   
      
   Maybe. But not as you say. You would need a simple 3v to 5v level   
   shifter (so as NOT to invert the signal) then the MAX232.   
      
   > ...snip...   
   >    Anyhow, peruse the usual spots, AdaFruit, SparkFun,   
   >    Seeed. They may have a canned solution.   
      
   sound advice.   
      
   --- SoupGate-Win32 v1.05   
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