Shop OBEX P1 Docs P2 Docs Learn Events
SX Controller Board — Parallax Forums

SX Controller Board

Bill ChennaultBill Chennault Posts: 1,198
edited 2007-12-21 03:24 in General Discussion
All--

I am always looking at different Parallax products. I ran across the SX Controller Board. I do not see any topics specific to this product on the forum. (Maybe I have not looked hard enough?)

Currently, my robot, Ugly Buster, uses five processors, a "master" BS2p40 and four OEM BS2 "slaves." I implemented a bit-signaling scheme so the master could tell the slaves what to do. One OEM BS2 is dedicated to simply controlling the HB-25 that controls a gear motor driving a track. Another OEM BS2 does exactly the same thing for the other track. There is an OEM BS2 dedicated to merely counting encoder pulses from the left gear motor encoder and another OEM BS2 dedicated to counting pulses from the right gear motor encoder. (The two encoder slaves bit-signal the master every four encoder pulses and when the master determines they are out of sync by four or more encoder counts, it signals one of them to stop and let the other catch up.)

All of this is done with I/O pins. It is FAST. However, I am always looking for something . . . else.·I really want an encoder·interrupt. That·is exactly why I decided to implement bit-signaling using Stamps. I do not want to miss an encoder count. I imagine that since the SX has an interrupt and·is so much faster than the fastest Stamp, that I could get by with two of the SX Controller Boards, possibly one. (Dedicated to the tracks, that is. Other functions will be handled by other microcontrollers.)

But, I have not found feedback on the SX Controller Board. Do you have general comments about the product that might be of help to me as I contemplate using it (or them)?

Thanks!

--Bill

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
You are what you write.

Comments

  • JonnyMacJonnyMac Posts: 9,217
    edited 2007-12-21 02:12
    I can comment because I helped create it; it is, essentially, and industrialized SX28. It gets used quite frequently by prop and FX builders; in fact, I'm working with the engineering staff at one of America's most famous amusement parts as they are intending to use it with their own DMX512 add-on for remote control of displays. It has a socket for the resonator so you can select your speed. Two bits of the RA port are used for the DB-9 serial connection, two others for the EEPROM (32K). You have access to all RB and RC port bits, and all are buffered to outputs through ULN2803s. RC.4 - RC.7 have configuration jumpers that allow you to pull these pins up or down as might be required for inputs.

    I recently wrote a program for one animatronics customer that has three UARTs (two TX, one RX), a virtual servo controller for four pins, and can take a measurement from the Ping sensor. The other I/O points are used as simple digital outputs. It's an SX with some muscles -- code away.
  • Bill ChennaultBill Chennault Posts: 1,198
    edited 2007-12-21 02:41
    JonnyMac--

    Thank you very much for the information! The SX Controller Board sounds like just the environment towards which Ugly Buster will evolve. I can imagine about four of them mounted in a block via those through holes.

    I wonder why they get such little mention on these forums? The SX Controller Board seems like a dream come true for a BASIC programmer needing an interrupt and some I/O pins. Breadboards are not long-term solutions for 'bot brains!

    --Bill

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    You are what you write.
  • JonnyMacJonnyMac Posts: 9,217
    edited 2007-12-21 02:44
    They're a bit new to Parallax; EFX-TEK customers have been using them for a few months, and I'm writing programs for them every day. In the end, it's an SX -- you could "roll your own" with an SX28 Proto Board, some chips and some solder, but, perhaps, having it all assembled and ready to go is appealing.
  • Bill ChennaultBill Chennault Posts: 1,198
    edited 2007-12-21 02:56
    JonnyMac--
    ". . . perhaps, having it all assembled and ready to go is appealing."
    As a non-electronics person, having it all assembled IS very appealing! (Although I am learning more every day.)

    --Bill

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    You are what you write.
  • JonnyMacJonnyMac Posts: 9,217
    edited 2007-12-21 03:11
    Well, you'll be happy to know that all of the RB and RC I/O pins are protected with 220-ohm inline resistors; this helps mitigate "accidents." Most of our customers are more artistic than electronic, and they have certainly appreciated this feature (shamelessly liberated from the Parallax Homework Board). All I/O pins have servo-compatible 3-pin headers which makes it really easy to attach things like the servos (duh...), the Ping)) sensor, the Parallax Serial LCD, and the HB-25 motor controller.
  • Bill ChennaultBill Chennault Posts: 1,198
    edited 2007-12-21 03:24
    JonnyMac--

    Thanks. I had read most of that. I am using seperate HB-25s now to control two Banebot 42 amp gear motors with encoders. Althougth the HB-25 is rated at 25 amps, my 42 amp stall current motors will never reach anything even close to 20 amps. I plan to use the HB-25 for all my motor control needs, even the small ones. This makes for good standardization.

    It looks like this conversation will be the inducement I need to buy some SX Controller Boards.

    Chris, how about an HB-50?

    --Bill



    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    You are what you write.
Sign In or Register to comment.