Another Digital Clock Circuit, Schematic, and Build Log

pic16f690 mcp23s17 ds1305 block diagram of clockI couldn’t take it any longer. I haven’t played in a long time so I decided to start from scratch and design another digital clock. I’m working on the board right now. I had one more display, RTC, and 32.768KHz xtal  left.

I am building my own display driver this time though. The display driver will be an MCP23S17 multiplexer and a PIC16F690 microcontroller. The display driver that I used in the Picaxe clock was about $8. Not counting the amount of time I’ve spent writing the code my display driver should be about $2. Plus, I really don’t want to have to buy a driver and then spend the money on shipping when I have what it takes to make something work. We’ll see how it goes. In theory it seems like it will work.

I’ll explain more in a few weeks. I’m also tackling this project to create a C header file for the DS1305. It might help someone else out who is trying to work with it.

Full Color LED: Radio Shack 276-028 $2.99 (More datasheet reading)

FullColorLEDCircuitBoardTopSept. 22, 2009 - Waiting on parts to come in can be boring so I went on a dig through my parts bin and found this LED still in its original packaging. While the packaging leaves a lot to be desired, I actually found the datasheet on RS’ website. I played with this LED and some 1k resistors on a breadboard, and now I’m going to make a night light that changes colors. The original program that I wrote lasts about 15 minutes, and it cycles through all of the colors [edit – at least I thought it would). It uses a rough PWM method that I wrote to fade in and out.

After a little math work I decided on using 20mA for all of my colors. They are rated for 30 to 50 mA depending on the color, but with this I can use the output pins on my PIC12F675. This saves a lot of transistors for another project.
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The Temp/Humidity/Dewpoint Datalogger: Final Product

Well, due to eBay difficulties, I was severely delayed in finishing this project. It seems that the person that I ordered my first blue LCD display from didn’t want to send a few folks their stuff this month. I went to check on the status of my order, and there were negative feedbacks from around the time that I placed it. So much for that. They sure were inexpensive.
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A better….Infrared remote light control system

Read below for history, but the final project is here!

This is an update to Infrared remote light control system. I never included the schematic, which is good because it was a great idea, but horribly implemented. Ten months ago I was only getting started with C, and now I know even more than before. I have updated the remote controller program and schematic to make it work even better. I used a sleep() function and the Watch Dog Timer to make it low power and to simplify the operation and construction. I’ll leave the old posting, but this is the best way to make the remote. I’ll disassemble the receiver and get a schematic out for that, someday.

POV: Persistence of Vision with a PIC16F690

POV ImagePOV ImageOver the past two days my wife and child have been sick so I’ve had lots of home time to POV Imagework on this project. It’s pretty amazing to me that I just started this PIC16F690 POV project less than two days ago, and I already have it finished and working. I worked pretty hard to get the C files completed for this. I also drew a board with Eagle, but I just used some scrap perfboard. Nothing in the world beats point to point soldering. It was actually pretty easy since there isn’t really much to solder in this project.

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