Increasing arduino UART voltage level

Other Hardware General Electronics
21

MorganS:
Looks like both C2 and C4 would be unnecessary if you did not need the voltage inverter function.

SoftwareSerial can invert the data. Some of the more advanced Arduinos like the Teensy can do it in hardware but SoftwareSerial will be easier.

have you tested the removal of C2 and C4? would love to hear your results.
you also mentioned connecting V- to GND, please elaborate about that.
my main interest is to have a voltage level of 0-12V instead of +-12V from the RS232 side. seems to me like if i remove C2 and C4 i would never get a voltage output at V- at all?
thanks.

22

I ran a quick test.
removed C2 and C4, V+ rail does show 2*VCC which is to be expected.
than tried inputting TTL and monitoring RS232 output:

"V-" rail not connected: TTL "0" or "1" both show RS232 output 1.3V.
"V-" rail connected to GND: TTL "0" or "1" both show RS232 output 0.5V.

So far the MAX3232 hack is not successful :frowning: