热度 20
2013-9-28 11:34
1500 次阅读|
0 个评论
When we bought the used signs online, it seemed like a good deal until we realised there were no instructions included. Anyone like me working in an operations centre knows that we'll never be given the resources required to truly do our jobs well. In a real sense, we are the redheaded stepchildren of technology, although perhaps I should rephrase that out of deference to my own family members with red hair. What I will say is that with extremely limited budgets, those of us who work in operations centres are constantly forced to find new ways to do things as cheaply as possible. That was certainly the case with a request to set up "wallboards" in our area. Management wanted to use these small, LED dot-matrix signs to display concise, "state of the company" messages so that people walking through our area would know they were on hallowed ground. At the very least, the hope was that the signs would give people the warm fuzzy feeling that they were truly in an operations centre. Cue the circus. A colleague found some used signs on eBay for a screaming deal, which in retrospect should have immediately thrown up a red flag. We got the signs and opened them up, only to discover that they could only be programmed through the use of an infrared remote, which wasn't included. We immediately flipped one over to look up the information on the back of the sign and found a nice, wonderful... complete void of programming code. The manufacturer had merely listed specifications for a communication protocol. We had no code, and we had no tools. Knowing that engineers are more likely to figure something out when they are told a task is impossible, we made it into a competition. Whoever figured out how to reprogram the signs would get to take one home. The gauntlet was thrown down, a lot of tries were made, but no forward progress was seen. And then the big revelation came: We let all of the smoke out of one of the signs. Someone referred to it as the sign getting "fried," but everyone knows that electronics run on smoke, and when you let all of the smoke out the electronics quit. Suddenly, things were looking up—who wouldn't want a broken sign? We cracked it open and determined that the chips used for communications were okay. We threw in some replacement inductors, after cracking open a second sign to see what values to use. Some tools would have been really handy here. The broken sign was operational again, but we quickly realised the maximum length of the message was limited compared to the other signs. Thinking this was a result of fried EEPROM, we cracked the sign open again and gave it a visual inspection. The black circuit boards were all on the RS232 end of things. It looked like we didn't let the smoke out of the EEPROMS. We had something else happening, and we didn't yet know what. This forced us to revisit the manufacturer's manual, which turned out to be not much more than a nice RS232 communication specification sheet. Luckily, we happened across someone who had written a limited Perl script, but it was more than we'd seen up until then. A few quick hacks later, and we had some clean C code to communicate with the sign. I personally like C because I can port it into a few different services. A few test runs and trials, and the broken sign looked to be up and running. The next step was to program ('programme' for plan) the other signs, and things looked golden over there, too. So for the cost of a screaming deal on eBay, our troubleshooting time, a few inductors, some coding time, and the remaining shreds of sanity that I lost, we now have it all: a warm, fuzzy-feeling-inducing work area that has become the "show off" place to bring new employees, members of the board, partners, and vendors. We have graduated from being stepchildren to core members of the nuclear family. The downside to all of this is that more people are now hovering around my desk, and it means I have to talk to some of them. Perhaps if the signs disappeared, that problem could be solved. Anyone want to buy some used wallboard signs? I'll give you a good deal, code included! Joe Lewis, a Linux engineer at overstock.com, shared this story as a submission to Frankenstein's fix, a design contest hosted by EE Times (US).