Support other than 8N1 framing

[werk-xyz]

Hello,

thanks for this great SoftSerial implementation for ESP8266.
It would be great if your library would support other than 8N1 Implementations of serial packet data framing (e.g. 7E1).

[scottwday]

Hi, thanks.
8 bit frames are pretty baked in to the code, but 8N1, 7E1 and 7O1 all use 8 bit frames.
For parity just check the MSb of the received byte.

The following code will calculate the parity for a byte by looking up the parity for each nibble:

byte calculateBitCountMod2(byte n)
    {
        const unsigned short bitCounts = 0b0110100110010110;
        return ((bitCounts >> (n >> 4)) ^ (bitCounts >> (n & 0x0F))) & 1;
    }

so you could do something like

    byte rxData = rxByte & 0x3F;
    bool parityOkay = (calculateBitCountMod2(rxData) << 7) == (rxByte & 0x80)