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Which basic stamp will support a baud rate of 57600bps — Parallax Forums

Which basic stamp will support a baud rate of 57600bps

SOUVIK SENSOUVIK SEN Posts: 1
edited 2013-08-27 08:23 in BASIC Stamp
I have a Tagsense ZR USB active rfid reader and ZT 50 active tag and i want to interface both of them to two basic stamps separately.But i am facing the following problems:
  • The reader sends out serial data at a baud rate of 57600 bps ,no parity,1 stop bit,no Flow Control.Now i don't know which Basic stamp module to use.
  • In the manual of the tag it is written that pin 0 on it is TTL RS232 output to an external microcontroller.In the BASIC STAMP manual it is written that TTL level output can be connected directly to one of the general purpose I/O but RS 232 output have to be connected via a series 22 k resistor.Now I am getting confused how to connect it to the BASIC STAMP ie, whether to directly give the output of pin 0 to the BASIC STAMP or connect a 22 k resistor in series with it (as it is mentioned the output is TTL RS232).

Comments

  • PublisonPublison Posts: 12,366
    edited 2013-08-27 07:28
    The fastest baud rate,( per the manual), for a Basic Stamp is 19200 with the BS2px. You could do 57600 easily with a Propeller chip.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2013-08-27 08:09
    The Propeller chip can go up to 3Mega-baud... proven. And it is cheaper than buying a BasicStamp.
  • Tracy AllenTracy Allen Posts: 6,662
    edited 2013-08-27 08:23
    welcome to the forum, Souvik Sen.

    The BS2p can send and receive 57600 bits per second with a baudmode setting of $17. The Stamp might have a problem receiving though if the tag reader reader does in fact send a packet with only one stop bit. The Stamp can keep up fine if there is a little extra pacing between the individual bytes, however, it will start missing bytes if they really come one right after another with exactly one stop bit. For that reason it is more likely to work with the BS2px (baudmode=$31). No problem at all with a Propeller.

    For the hardware, you should be able to connect the tag directly to the Stamp input, however, I'd still put in a 1kΩ resistor for assurance. RS232 levels from the old days are at higher level both positive and negative. When they say TTL level RS232, they usually mean 0 to 5 volt levels but using the same serial byte encoding as RS232.
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