Well, as far as viscometers go, I could be considered an expert by now (no, not really). Today my new board arrived and I assembled it, I’m kind of proud of it, it works real slick just like the last one. This one has the following changes
ICSP provisions so that I can program it in place.
a PIC18F2620. Has 10 times the program memory and RAM.
diode protection in case the power is hooked up wrong.
Fast recovery diode for motor induction absorption.
Larger traces for the motor.
Fixed resistor array.
Anyways, here is a comparison shot. Old on the left, new on the right.
Well, I’ve built it, the useless yet fun, timer lamp. The idea behind the timer lamp is to have a bedside lamp that you can turn on and of but also set it to turn off after a certain amount of time. This task is pretty easy but I wanted it to be controlled by a micro controller. After two years of thinking about it I finally got off my duff and built it.
Here’s a blow by blow of how it was built.
First I took the thing apart. The wire itself is pretty tough to chew on so I kept it in there so I can save the lamp itself. The lamp was bought from Wal-mart for about $18.
Here’s a blurry pic of the control board I designed. It’s generic in that it can take both digital and switch input and output 200ma per channel on 3 outputs. It’s nothing special but it’s small enough and it works. The MCU on it is a PIC16F505, not a great MCU but it works.
And here’s the casing on the base. Inside was some sort of bizarre weight made of something I did not want to cut. I took the guts out and popped two 5/8 holes for the buttons. I didn’t have a proper drill so I used a forstner bit, not ideal bit it worked surprisingly well.
I inserted the guts of the machine and had to follow the existing wire in and keep the controller towards the front. As you can see, it’s pretty ugly, as well I used hot glue to affix the boards to some wood which was then affixed with hot glue to the inner casing. It’s not an ideal solution but it relieves me of having to use bolts and it was fast.
And there you have it, it seems to work. No fire, or smoke and it works as programmed (kind of). Now I’ll have to go to work and build a new base, one to keep the unit steady, also I think I’ll add a little piezoelectric tweeter for audible confirmation of time selected.
Anyways, I’m glad I made it this far on the project in such a short amount of time.
Well, they turned out about as good as I’d hoped, the new PCBs are pretty cool. This whole time I’ve been learning electronics I’ve been building boards by hand; That is a foolish move. I took Sam’s advice and got them done up at APCircuits and the result was good. Here are some pics!