Larry's Blog

Here is a look at my Verge & Foliot escapement
in action
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Here is a look at how I am hooking up a PC KEYBOARD to my microcontroller – the PIC16F628.

I found an article on the inernet that explained the protocol of a PC keyboard. Not as bad as I thought! Only 2 lines for CLOCK and DATA. Other 2 lines for +5 volts and a return. The keyboard sends serially, but not the asciii codes themselvesw, but scan codes, which have to be translated. I had to do a lot of debugging of my code but I’m having success now.
I can also display alphanumeric data on my LCD, make it blink, and have it rotate across the screen. Much fun!!

SUCCESS with programming my alphanumeric LCD display!!!

Here is a picture of setup for experimenting with Ferromagnetic Core Memory.
On the left you will see a composition electronic card containing ferrite cores
which have been cemented right in the card. I have removed all the original wires from it. The next circuit to the right of it is a latching circuit with an LED which is designed to latch a signal coming in on the sense wire. There is other circuitry for the WRITE signal which magnetizes the core in one or the other polarity.

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I set up a circuit using one of my PIC microcontrollers to control an ADC0804LCN analog to digiital conversion chip. I measured the voltage on 2 AA batteries I had lying around. When I measured the batteries in series with my voltmeter, I got 2.81 volts. So after considerable circuit debugging and also debugging of my simple PIC program called ADPGM.ASM, I got the output which for the time was displayed in 8 LEDs. The output was as follows:
—MSB———-LSB
—-1 0 0 1 0 0 0 1—–
In decimal that is 145. So:
—–145—- —X—–
———— = —————and X = 2.84
—–255— —-5—–
Not bad ! My A/D chip can make a conversion in 100 usecs. So if I allow about 25 usecs for my computer pgm to store each sample voltage of an incoming signal, I could take 8000 samples a second !!!! Of course, my PIC program controls the number of samples I choose to take. I will be using this A/D converter to analyze speech and compare spoken words to some kind of template for comparing and identifying the words.

Well, I was looking for a new project, and decided I would use several PIC microcontrollers connected together. There would be some kinds of displays which would show menus to the users But the main thing would be that the computer would talk to the user, and the user would reply by voice.
So I have already mastered using the Chipcorder with which the computer can voice a variety of messages. But I also want the computer to be able to recognize “yes”, “no” and maybe up to a dozen words and numbers.
So what is SPEECH RECOGNITION ?

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Here are some images I’ve generated on my
64 X 128 Graphic LCD

I have been using the PIC microcontroller to read the codes sent out from handheld remotes. I was even inspired to construct a maching that woulkd print out the various codes when I pressed one of the buttons on the remote. Here it is!

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Just yesterday I determined to find a way of producingelectronic bell sounds.
There are some challenges here. A bell sound is a damped oscillation, that is, the frequency remains the same but the amplitude diminishes to zero. Also, can I use simple square wave for frequency or do I have to produce a sine wave?
There is also the question of attack. I believe this is the high amplitude of the beginning of the bell sound.

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Here is an e-mail I just sent to my friend George Gallant
all about a new area for me:
OBJECT DETECTION AND AVOIDANCE FOR ROBOTS

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