I’ve been very very busy working on a project that is due very soon. In fact, it’s taking up almost all of my free time so I’m very sorry if I am unavaliable at times. Anyways, here’s a little on what I’ve been up to:
Progress as of yesterday.
This is a clock running on a PIC 16F84, and multiplexing 7 displays. The transistors are to drive the display. There’s a 1Hz clock generator from a cheap alarm clock to keep the clock on time, a 555 to feed the clock signal to the PIC, a CD4017 decade counter for the display, and another PIC to coordinate everything. The 300+ lines of code for the PIC was written from scratch using mikroBasic.
The 1Hz clock generator is “floating” on the 555.
I’ve been working on this for 2 weeks already. Most of the trouble was in the coding of the PIC itself. Making an accurate clock is not as easy as it seems. And trying to juggle between updating the multiplexing displays and making time calculation makes the code harder to write.
And while building the final version here, I accidentally left out 2 tracks that I should have cut. When I applied voltage, two transistors went to the Great Spare Parts Bin in the sky with a loud bang.
The final version will be squeezed into a small circuit board and mounted somewhere. The exact location cannot be revealed yet. So stay tuned!
Here are some pictures taken from the Airforce museum. I didn’t take them and I haven’t been there either. These are just some interesting pictures that I think you would like to have a look at. Mostly WW2 planes.
Variable pitch propellers.
4 engines on this small plane.
This plane can land on water as well.
Bevel type reduction gearbox.
Two seater light aircraft.
In-line 4 piston engine fighter plane
Radial piston engine fighter. This plane is known as the “bulldog” if I’m not mistakened.
How a radial engine looks like when unmounted.
The cylindrical cover in front of the propeller houses the pitch change mechanism.
This plane was used as a trainer in the past.
A turbine engine that drives a propeller. Also know as a turboprop.
One of the first planes delivered to the RMAF: The Twin Pioneer.
I’m a sucker for old technology and stuff. If I was born 50 years ago, I would feel very comfortable around these devices. But I’ll miss the Internet, PICs and a whole lot of modern stuff. So I’m not complaining much. Now what I can do is try and get my hands on these antiques!
Nixie clocks are actually clocks with nixie displays. Nixie display displays the time using filaments in the bulb. There are individual filaments for each number. So if you want the number ’9′ to light up, you supply power to the number ’9′ filament.
These are some examples of home-made nixie clocks.
Haven’t been blogging for more than a week now. Been quite busy actually. Taking courses now so not much things happening. The haze is bad and I was down with mild fever and cough. Must be caused by the trip to Pudu the other day. Walked from Pudu to Time Square and back again. Must have walked 5km that day?
NEVER do multiplexing on 6 displays on an experimental board. The wires will drive you crazy if the coding doesn’t.
I’m working on a secret project here involving time. Seems like trying to measure 1 second (or rather to get a 1 second clock pulse) is not as easy as it seems. Makes you look up to those sub-RM10 clocks that can keep time to as accurate as few seconds a year.
Found this VFD for a bargain price of RM10 at Pudu. Problem is, it’s so old that even Google doesn’t know about it.
Today is a holiday for Selangor. So having the day off is great. Helped my cousin hack a n70 casing for his assignment. Basically he needs a light on when the rear camera cover is slid open. Quite a lot of fabrication and waiting for the glue to dry, I finally managed to pull it off. The hardest part was figuring how to mount the switch.
Blue glow. Nice.
Luckily there was a notch on the casing so I just put a strip of metal there. When the case was slid open, the contacts would move and touch each other. The battery was from a pen mounted torch light.
After coming back from Port Dickson on Sunday, my brother and I decided to try and start the old abandoned car, which was a Ford Corona. The owner was selling it as scrap metal so it was about RM300. It’s still on its wheels and the engine and gearbox and aircond is still in place. But we’ll soon find out why it was worth RM300.
2.0 inline-4 SOHC carburetted engine.
First we tried starting the car with jumper cable leads. But the leads couldn’t supply enough power to turn over the motor. Then I decided to remove my car’s battery (ouch! there goes all the ecu settings) and put it in. The starter motor managed to crank the engine nicely. Now we need some fuel.
While my brother went to his room to get some fuel (if there’s a fire at INTI, block E will go down the fastest), me and my friend tried to open the fuel filler cap. But a key was needed and the key that the owner gave didn’t fit. So we tried to pour gasoline into the carburettor to try to start it. The engine was cranking but it didn’t splutter to life. We checked the ignition cables, and they were working perfectly. Our only suspect was the spark plugs. But since we don’t have the spark plug opener, we couldn’t inspect them.
We gave up on the car after discovering that the gearbox is stuck in reverse. Continue reading →