Bar Monkey Relay Assembly

Relay Kit CompleteSo Alan has made some good progress on the Bar Monkey. The relays are mostly complete (a few nights soldering between grading finals) and the next step is testing them out.

According to Alan the relays were fairly straight forward. The only big challenge was figuring out the orientation of the IC chips. Thankfully they mount in sockets so it’s fairly easy to switch them around.

Check out my Bar Monkey Gallery for some pictures of the relay in various states of assembly.

Check back often for updates on the project!

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6 thoughts on “Bar Monkey Relay Assembly”

  1. A followup… We tested these relays last night and it looks like interfacing with them is going to be a snap!

    Everything worked as expected except one relay seems to be broken (one channel on one of the 8-channel boxes.) Thanks to the large connections and a logical PCB layout (see pics) it was very easy to troubleshoot.

    Alan’s going to contact the vendor for a new relay. We’ll see how good their customer service is!


  2. UPDATE: At 10:00 this morning, I emailed Carl’s Electronics ( explaining the dead relay situation. At 11:20 I received confirmation that the part has shipped! Now if I can just get this damned software working. . . It appears that Java had serial port support once upon a time, and has since abandoned it for Windows. I’ve found an old release of the javax.comm package for Windows, so fingers crossed it will work. Otherwise I’ll need to abandon the XP embedded OS in favor of Linux which Sun still has serial port support for.

  3. Yet another update: So it turns out when you use the Kit 108 upgrade to join two kits together, you need to change the way you talk with the relays. Instead of just say “N1” to turn on relay 1, you need to say “N01”, basically make all of your relay numbers two digits. So I’ve hardwired 12 volts from the power adapter directly to the relay kits, and was able for the first time to test the kits hooked together. Everything worked fine once I figured out what I needed to do to talk to them.

    The most exciting part though, after fighting for 5 hours straight tonight with the software, and trying to get java to communicate with the serial port which they don’t support, I was finally able to get it working. By making system calls to to set the proper speed & other settings of the com1 port, I was then able to open com1 as a file and write to it with a file output stream. There is a bit of a problem with reading and writing to the port, because you can’t have both an input and output stream to the port at once. My solution was to create a file output stream immediately before writing, and closing it immediately after. This does seem to be a bit of a kludge, and certainly has some serious performance issues, but at the moment, I’m more concerned about making it work and polishing it later.

    After so much work on this little project, it was music to my ears to hear the symphony of clicks coming from each of the relays … for a while there I was afraid I was going to have to switch programming languages because of Java’s suck support for the serial port. Why they would drop support for a popular port on the most popular Operating system but provide support for Linux and Solaris is beyond me and doesn’t seem to be a good move on their part.

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