I’ve been wanting to get into electronics. I have so many kits, parts, books, and ideas. But nothing really put together. I had thought about creating a device to count the number of times that a ping pong ball hits the backboard, but I’m not really sure how to measure each hit. I was thinking of using a microphone and counting pulses, but I’m not quite there yet.
Then at the “Executive” meeting at the HP Houston Toastmasters club (I’m the newly elected VP of Education), there was an agenda item to consider buying a speech timer. You would program the minimum and maximum time. Then click start. And it would turn on a green light once you got to the minimum time. It would show the yellow when you were halfway between the minimum and maximum time. And then it would show red when you get to the maximum time.
So, this all seems simple. I know how to program a basic stamp from parallax to turn on lights, respond to buttons, and display things on an LCD screen. I just need to put them all together. So, stay tuned with the blog to see how I go about doing that.
I have created a wiki page for the project to so you can look at the latest design: Speech Timer Wiki Page
Yesterday, I successfully hooked up my Basic Stamp board to my laptop, wired up an LCD display, and completed the “Experiment #11: A Basic LCD Demonstration”. This showed me how to actually get something to show up on the display.
Today, I need to do “Experiment #30: Using a Real-time clock”. This will ensure that I can count the seconds and minutes accurately. And I want to combine what I learned from #30 and #11 to show the time on the LCD screen. So, lets see how that goes.
Experiment #30: Using a Real-time clock
We use a DS1302 real-time clock (RTC) and a 32.768 kHz crystal hooked up to the stamp.
The crystal has no external markings, but I found this picture on digikey: 
The total length is about 1/2 inch. The component part is only 1/4 inch long.
Need a 1k resister.. What are the color bands? Time to google… ahhh Here we go:
www.micro-ohm.com/colorcode/rescolor.html
Brown-black– red
double check with VOM
Got everything hooked up… sample program loaded.. but the time does not increment…
I wonder if the DS1302 or the crystal has gone bad?
Well, that’s all for today.. Hopefully I will get a chance to look at it more tomorrow.