I fixed the alarm sound. With the Senior Project clock, the buzzer and the buttons were connected to the same port. On the new clock, they were connected to different ports. I did not update the button reading routine correctly, so the buzzer output was not working at the moment a button was being read. This resulted in a little distortion being introduced into the signal going to the buzzer. This was easily fixed once I figured out what was causing the problem.
However, I made a discovery while troubleshooting this problem. While looking at the buzzer’s waveform on an oscilloscope, I saw voltage spikes being generated by the buzzer’s coil. I realized that I needed to add a diode to the circuit to protect the microcontroller from these spikes.
Continue reading Fixed alarm sound
I assembled the first board, using a Zero Insertion Force (ZIF) socket for the microcontroller. The socket has a lever to release the microcontroller so it can be inserted and removed without any force. This allows it to be removed a lot easier for programming.
I adjusted the code for changes in the pin assignments and got the new clock working, except the alarm sounds strange. I suspect it’s a software issue of some sort, but will have to troubleshoot it later.
Continue reading Built the prototype
After making the jigs, I had enough wood left over from my sheet of MDF to make 40 frames. I had some issues which damaged some of the frames as well as mangling some of my jigs making them useless. However, I did end up with 30 good frames.
Now I know how to make the next set of jigs to avoid these issues, make the process faster and get more good frames out of my next batch!
I showed one of my frames to my friend, Denny, who made the frame for my Senior Project, and he said mine came out better than his. Looks like I got this part down! 🙂
I decided to try to make the frames myself. The first step was to make some jigs for holding the wood to make it easier to manufacture the frames. I got a sheet of MDF, made the jigs and cut the rest of the wood down to size in preparation of making the frames. And my new PCBs came in, along with more parts to build more clocks!
Several changes to the schematic and PCB layout had to be made.
- Corrected which pin drives the buzzer – The issue with RA4 inadvertently being connected to the LED matrix has been corrected in the new layout of the PCB.
- Moved the Alarm and PM LEDs – When either or both of these LEDs are lit, it makes it more difficult to determine the time, especially in low lighting conditions. Perhaps moving these LEDs closer to the center of the board will help with that. Other options in software may be explored,for example, making these LEDs dimmer.
- Continue reading Changes to PCB complete
After a bit of a slow start, I have finished making the adjustments to the frame. It will be 1/8″ (3mm)thinner, which may not seem like much, but it brings the tops of the larger LEDs flush with the face of the frame. The rounded edges of the frame will have a larger radius, to give it a more sleek and rounded look. The back side will have a couple of modification as well that will aid in its manufacture. I needed to start with the frame as the changes will have an effect on the PC Board’s size and location of mounting holes.
I can’t believe it’s been two months since I graduated! I have (finally!) officially decided to make a kit available based on my Senior Project. It was actually in the back of my mind when I drafted my proposal the semester before. Truth be told, when I first thought of the idea several years ago, it was with the idea of selling it as a kit. Now it is finally going to happen!
There are numerous changes that need to be made. Most importantly, the PC Board will have to be re-spun to correct the RA4 output error. There are some other minor changes I want to make to the board as well. I want to make the frame a little thinner and make some other small modifications that will make producing it a bit easier. Finally, there are some additional features I want to add to the software – like the ability for it to keep time to a 50Hz reference as is used by the electric utilities in some other countries.
Today, I submitted my senior project! It consisted of my report (which turned out to be 41 pages, complete with pictures, schematics and references), a presentation poster (which I threw together one evening), and the video. I think it all came out pretty good. It is due by the 26th. I was hoping to get it in a week or two early, but some things ended up taking longer than I thought. It was a good thing that I planned to get it done early. I should get a grade by early next week.
Update May 3: I got my grades! I scored 100% on all three: the report, the poster, and the video!!!! 😀
I have a friend, Joel, that has actually made a couple of movies. Although he is an amateur movie maker, his movies came out looking rather professional. He agreed to help me make my video. It was to be between 10 and 15 minutes long — points would be deducted if it’s under 10 minutes or over 15 minutes.
Joel said that if I came over after work on Friday, we could get the shooting done by 10pm and finish the editing by midnight or 1am at the latest. It turned out that we didn’t get finished with the shooting until about 1am! Then there was the editing!
Continue reading The video
The software is fully functional now. The clock’s software does not have everything I had hoped to implement, but it fully works as proposed! I really have to get the report finished. Of course, there are some specific requirements for the report including this suggestion concerning its length:
Although the quality of the report and the length of the report are not necessarily related, if you submit fewer than 15 pages for the combined introduction, discussion, and conclusions, you most likely have not adequately described your project, its history, your research, computer simulations, and the results.
Yikes! I still have a lot of work to do! And then there’s the video ….