Shop OBEX P1 Docs P2 Docs Learn Events
stamp life expectancy — Parallax Forums

stamp life expectancy

TintinTintin Posts: 37
edited 2006-07-19 16:27 in BASIC Stamp
I'm thinking of using a BSP40 for an industrial control.· The·stamp would be running constantly 24/7 monitoring temperatures and activating relays.· Is there any problem with·running a stamp·microcontroller continuously?

In the·past·I've only used stamps·for small·projects where·most of the times the unit is turned off.

Thanks,

Frank

Comments

  • allanlane5allanlane5 Posts: 3,815
    edited 2006-07-19 15:33
    Shouldn't be. One of the nice things about the BS2 series is that it is relatively low-current, and they've taken care of most of the reliability issues (temperature range, oscillators, power issues).

    I'm sure others have used it in long-duration runs.
  • Tracy AllenTracy Allen Posts: 6,658
    edited 2006-07-19 16:06
    The only thing that has a life expectancy as such on the Stamp is the eeprom, so you should avoid repeated WRITEs to the same eeprom location. The Stamp is very reliable, in part because of its single tasking nature, no interrupts or hidden processes.

    On the hardware side, take care for what will happen in case of blackouts or brownouts and protect the wiring from ESD and from sources of spikes that might reset the processor. Give adequate protection from spills and accidents and possible miswiring of external cables. Battery backup if necessary. The usual industrial stuff.

    On the software side, take care for modal loops, loops where your program could get stuck waiting for an input that never comes. For example, if a sensor becomes unplugged or defective, or a serial string does not arrive, that should not be allowed to lock up the whole program.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Tracy Allen
    www.emesystems.com
  • Philip T.Philip T. Posts: 8
    edited 2006-07-19 16:14
    My BSII has been in my Isuzu Trooper for 2.5 years controlling the shock absorbers. It is on when the truck is on, 1.5-2 hours a day in the Florida sun with no AC.
    It has never required a reload of the program or stopped working.
  • stamptrolstamptrol Posts: 1,731
    edited 2006-07-19 16:17
    Tintin,

    No problem with using the Stamp in industrial projects. I've got some Stamp based units which have been on and running 24/7 since late 1996 without any issues, including power failures, nearby lightning activity, etc.

    Take care with the field devices connected (use opto's or clamp diodes, etc) and stay within ratings of any relays, transistors, etc.

    Cheers
  • Beau SchwabeBeau Schwabe Posts: 6,557
    edited 2006-07-19 16:27
    Not to be biased, but before I started working for Parallax, I designed an industrial automatic blower/vacuum system still working today (8+ years).
    The system basically monitors various machines to "detect" if they are ON or not. If any one machine is ON, then the vacuum system turns ON
    immediately via a 40A relay connected to a BS2. When ALL machines are OFF the vacuum system continues to run for approximately 5 min before
    turning itself OFF. As far as writing to EEPROM, this system also keeps histogram data as to which machines are most frequently used.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.

    Post Edited (Beau Schwabe (Parallax)) : 7/19/2006 4:30:53 PM GMT
Sign In or Register to comment.