Shop OBEX P1 Docs P2 Docs Learn Events
Simple Serial Slave Output Module — Parallax Forums

Simple Serial Slave Output Module

Jon WilliamsJon Williams Posts: 6,491
edited 2005-03-28 20:43 in General Discussion
Per a discussion on the Methodz of Madness Halloween props forum I created this project; a very simple serial slave module for expanding outputs on BS1 and compatible controllers (hence the baud limited to 2400).· The program is written in SX/B version 1.2 (available soon!) and shows how declaring subroutines in SX/B 1.2 makes them easier to use -- in fact, no more "jump tables" or page boundary issues.· A very simple BS1 test program is also attached to verify all module features.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA

Post Edited (Jon Williams) : 3/27/2005 11:19:43 PM GMT
TXT
TXT
OE-8X.SXB.TXT
5K
TXT
TXT
OE-8X Test.BS1.TXT
2K
OE-8X Serial.jpg
962 x 558 - 63K

Comments

  • allanlane5allanlane5 Posts: 3,815
    edited 2005-03-28 19:51
    Neat! A couple of questions.

    1. You show the SX MCLR tied high, with NO resistor. Is this correct?

    2. You don't show the ULN2803 connection to +5. Is there one?
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-03-28 20:22
    MCLR is an input and unless it's going to be pulled low by a reset switch, I don't think a resistor is required. I could be wrong on this and I expect someone will correct me.

    There is no +5 connection on the ULN2803 -- its inputs are to the bases of Darlingtons and the outputs are the collectors; the emitters are tied to ground.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Jon Williams
    Applications Engineer, Parallax
    Dallas, TX· USA
  • allanlane5allanlane5 Posts: 3,815
    edited 2005-03-28 20:43
    Aha, so basically each of the ULN2803 "outputs" are providing a low-resistance path to ground when each "input" is at +5, and providing a high-resistance path to ground when each "input" is at Ground. Thanks.
Sign In or Register to comment.