IoT-ifying An Old LED Signboard

Scrolling LED signs were pretty keen back in the day, and now they’re pretty easy to come by on the cheap. Getting a signboard configured for IoT duty can be tricky, but as [kripthor] shows us, it’s not that bad as long as security isn’t your top concern and you can tweak a serial interface.

dec-16-2016-10-57-pm-edited[kripthor] chanced upon an Amplus AM03127 signboard that hails from the days when tri-color LEDs were the big thing. The unit came with a defunct remote thanks to leaking batteries, but a built-in serial interface offered a way to connect. Unfortunately, the RS-232 standard on the signboard wants both positive and negative voltages with respect to ground to represent the 1s and 0s, and that wouldn’t work with the ESP8266 [kripthor] was targeting. The ubiquitous MAX-232 transceiver was enlisted to convert logic levels to RS-232 signals and a small buck converter was added to power the ESP. A little scripting and the signboard is online and ready for use and abuse by the interwebz — [kripthor] says he’ll regret this, but we’re pleased with the way the first remote access turned out. Feel free to check out the live video feed and see what the current message is.

Personally, we don’t have much use for a signboard, but getting RS-232 devices working in the Arduino ecosystem is definitely a trick we’ll keep in mind. If asynchronous serial protocols aren’t your strong suit, you might want to check out this guide to what can go wrong by our own [Elliot Williams].

16 thoughts on “IoT-ifying An Old LED Signboard

  1. I used to maintain the messages on these signs installed in a small chain of restaurants in ’95 or so. I grew to hate these signs with near abandon. They were networkable via a dial up modemn but the company was too cheap to pay for the service. The number one most annoying feature with the remote with the boards was that you couldn’t correct typos, one had too redo the entire message. The second most amazing feature is the messages would be erased when the power was cut. That’s right, guess who had to reload the signs after a power outage?

    They were the whopping tri-colors too.

    I was sorely tempted to gut the shitty things once and for all and send them to their graves. But after about nine months of hell, the company decided they weren’t cost effective and got rid of them.

    1. Or individuals would run filthy facilities for work.
      When I was a boy, I long anticipated being a computer/electronics technician and now I actually
      have that job doing component-level repair on dreaded Macbook computers.

      Why I mention this? Try working with someone that is concerned about prophet margins ONLY.
      My boss runs a filthy repair store. Computer parts lying everywhere with a narrow spaces to walk
      between, “Harbor-freight tier” screwdrivers, and a desk that is never in the clean condition that I left
      it because, His female “friend” wants to come over. Or him watching “cringe compilations” or
      celebrity blunder of some Hollywood whore at full volume.

      Trying to bring up logical points, Like “the days of disposable electronics are coming to a end
      due to the collapsing economy” or “keeping computers stacked like tall decks of books are bound
      to fall over and break”. He just doesn’t care.

      I completely understand your struggles. But I’m afraid companies or individuals are willing to
      have their nose up the asses of those who pay the greatest buck… While running a bare-minimum
      work place just to retain prophets. Not caring at what struggles their workers may face.

  2. There are both kits and fully assembled boards readily available cheap to do 3v3-RS232 conversion; the MAX3232 is a better chip compatible with both 3.3 and 5V power and logic levels. Sparkfun has a fully assembled breakout for six bucks.

    1. We had one of these (different model) donated to my hackerspace.

      After failing to get the actual serial input working (using lots of high-end tools) I finally just took a cheap serial-to-USB converter and wired it directly to the 5-volt RxD and TxD pins on the controller chip.

      The cheap chinese converters don’t use or generate actual RS-232 voltage, they just route the 5V I/O from the USB chip directly to the RS-232 pins on the cable. Most of the time this works, and when it doesn’t they don’t really care.

      The 5V TTL levels is exactly what the micro wants to see, so doing this works very well as a conversion technique for devices that serial ports and have micros.

      We hung it on a wall at the space and connected it to Slack with a text-to-speech interface. People online can see members through the cameras, and send them messages to be spoken and displayed by the sign.

      IOW, it’s neat but completely useless :-)

  3. I have an older tri-color running in the garage now. Using it to stream RSS news feeds while I’m out there working. The sign was originally a serial interface (488 type) but I found an older 488 to Ethernet hard wire pot adapter. A Wifi bridge and I can now talk to the sign via my network in the house.

    There are some third party software packages you should check out if RSS feeds are interesting to you. Waveware RSS’s demo package is working on the sign but at $350 an installed license I doubt I will run that beyond the demo period.

  4. I’ve been wanting to do this for a while with my BetaBrite LED sign I salvaged from a broken CA Lottery clock. Also had some RF accessory it would pull the data from FM radio station data somehow IIRC. Might be a great reason to get into SDR…

    1. It’s an editorial “we” that we use when writing for the site. When I’m expressing my own opinion or relating a personal story I use the first person singular. It’s a style thing.

      1. I recently acquired two fast deployable emergency message boards (unused-Cheap as f*ck) from the State Highway patrol. This is exactly what I was thinking about doing with them. I just don’t want to be included in the “we”

  5. It’s crazy to see (bad) code I wrote eight years ago to scratch a particular itch still getting use today. Interestingly enough, I myself am still using my python script for a display over my office door.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.