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Serial Config help.

YT2095

I need to configure the Serial on an Arduino to match a very strange Printer, I`m not even sure it`s possible with an Arduino?

it needs to be:

 

1200 Baud

1 Start bit

7 Data bits (LSB first)

1 Parity Bit (Even)

and 2 Stop Bits.

 

Does anyone know how config for this in Arduino, or even if it`s possible?

 

Thanks image

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  • 0

    Wow. A lot of people have no clue how serial data works.

     

    1 start bit is pretty standard.

     

    "...don't know anything that still uses it..."

     

    rubbish. EVERYTHING uses it. An idling serial stream is sending "mark" (logic 1 -- which will be a negative voltage if RS-232RS-232 or positive if TTL). When a byte is ready to be sent, the data line is commanded to "space" (logic 0 -- positive if RS-232RS-232 or 0v if TTL). This is your start bit. When the receiver detects the logic 0 it knows to begin timing and extracting the bits.

     

    Yes, LSB first is "normal." No worries there either.

     

    Edit: Never mind extra bit I was adding to Salvador's bitstring. He has it right.

  • 0 in reply to Former Member

    Hi CookeMonster,

     

    Yeah, that "previous poster" was me! :-)

     

    I believed that UCSR0C was a byte, why do you have 9 bits? I understand that the bits that specify the word length are 3 bits, but 2 of these are in the UCSR0C and the third (MSB) is in the UCSR0B register.(bit 2). Thanks! Salvador

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  • 0 in reply to SGarciaV

    Yes, it should be 8 bits. I counted 7 in your post. Let me put my reading glasses on and look closer. The "1" on the right needs to be 3 bits "in". Back in a flash...

     

    Edit. Yep. I don't know how I counted that wrong. Your string is correct. Original message edited.

  • 0 in reply to Former Member

    CM says:  (start "S", 7 data bits "x", even parity "P", 2 stop "SS")

     

    If the data line is held high all the time just to let the device know that it is connected, then okay.  I did not know that was the standard; seems a waste of electrons, IMO.

     

    If the parity bit must be present does that printer even use the parity bit?  or ignore it?

     

    So, we have

    newChar = (double((asciiChar * 8) +7)| oxf000);   //  will give  11110xxxxxxxP11

    or

    newChar = (double((asciiChar * 8) +3)| oxf000);   //  will give  11110xxxxxxxP11

    or even

    newChar = ((double((asciiChar * 8) +7) *16) + 15);   //  will give  0xxxxxxxP111111

     

    Is one of those going to work?