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Response to Gran Turnio

larrykeegan — Thu, 18 Jun 2009 07:07:57 +0000

ALPHANUMERIC DISPLAY AND KEYBOARD

larrykeegan — Fri, 26 May 2006 19:11:01 +0000

Do you realize you can pick up older keyboards for one dollar! I have a few and use them to interface with my computer chips. I have done more work on my alphanumeric LCD (liquid crystal display). I can now set addresses and send ascii characters to these locations. The lcd controller automatically increments or decrements, each time you write to an address.

I am now able to read the contents of the DD RAM. The bytes of this memory correspond to the characters appearing on the display. The character generator is transparent to the programmer and produces the pixels that form the characters displayed. A very interesting development is serial rather than parallel LCDs. These seem to cost
$45 and up whereas the parallel type go for 10 to 20. It is desirable to have LED backlighting for good visibility.

SONG MAKING CIRCUIT

larrykeegan — Fri, 26 May 2006 17:22:35 +0000

Here is a version of a circuit that plays music. The program actually calls subroutines called doe,ray,me,far,sew,la,tea,doo. I have done lots of pgms on generating sounds, but this one attempts to get accurate mnotes of the musical scale. Some of the ideas came from an artice by G. Y. Xu in Nuts & Volts magazine.
So far this circuit plays Westminster Chimes and the theme played a race tracks for the start of the race. My circuit plays the notes as regular tones or as bell chimes.

PARALLEL & SERIAL MEMORY CHIPS

larrykeegan — Sat, 29 Apr 2006 16:55:44 +0000

Here is the very interesting story about 2 kinds of memory chips. One is a parallel type and one is a serial type. The serial memory on the right has only 8 pins. The traditional memory chip has 15 pins for address, and 8 pins for data. Obviously to access this chip, a lot of wiring is needed! Then how can the 8 pin chip be accessed? The answer is by sending a serial stream of data to it. This serial stream might be as follows:
command to write, part of address, other part of address, data to be written
This would be 4 bytes of info sent to the memory chip, along with a clock pulse on another line to guide the reception of the info.
So, can you see the tradeoffs?! The chip with all the pins is heavy on HARDWARE and wiring. The chip with the few pins is heavy on SOFTWARE and intricate programming.
Well, I opted for the small serial chip which can hold 4096 bytes of info. I had to grapple with the intricacies of software. I discovered that I had a bad solder connection on the CLOCK line SCK going from the PIC to the mem chip. I finally have it under control and have dozens of plans for usinbg it. By the way, this is an EEPROM chip. It is a non-volatile memory, but you can write over it up to one million times. These chips only cost about a buck.

POSTINGS IN YAHOO & GOOGLE GROUPS

larrykeegan — Sun, 17 Jul 2005 10:49:01 +0000

I have been posting info about my current project with emphasis on the SPEECH RECOGNITION aspects. Here is a posting I put out on YAHOO.
In my latest project utilizing several PIC microcontrollers, I need to have
communication between the system and the user – who may be a random
operator – say at an exhibit. Besides LCD’s and other types of displays, the
computer will communicate with a menu of voice messages using a
Chipcorder. But I want the operator to reply in a small vocabulary of spoken
words – IWR they call it – isolated word recognition.
Now I am beginning to learn there are a number of chips out there called
VPRs – voice recognition processors.
However, I want to try my hand at the nitty-gritty of speech recognition
circuitry myself. I am learning about A/Ds and DACs and I want to use a mike and an amp and digitize some individual words and see what the templates of the
sigs looks like. Then I would like to develop algorithms for comparing one
digitized template against another. Sound like fun to anyone?
Why let those engineers who developed these VRPs have all the fun? I like to
hear if anybody has tried one form or another of speech recognition.

PROGRESS WITH LIQUID CRYSTAL DISPLAY

larrykeegan — Sun, 12 Jun 2005 20:57:35 +0000

I have developed several subroutines which have been tested and work pretty well.
dspyon – turns display on showing what is in memory
dspyof – turns display off
strtln – specifies line in mem for top of display
shftwd – my routine to shift a byte of data serially to DB0-DB7
write – after page, y-addres, and number of writes have been set
and content of byte to be written have been set, it
writes up to 64 byte-columns (1/2 of screen) across the screen
setpg – allows page to be set from 0 to 7
sety – allows Y address to be set from 0 to 64
reset – resets the LCD
enabx – performs an enable, enabling the action specified by the information on
the bus DB0-DB7 and setting of D/I pin and R/W pin.

Today I have been able to generate a few design patterns on the screen, and have been able to scroll the images upwards. I have a routine to clear memory
but I notice from image on screen that one bit is not being deleted leaving 8 lines
across the screen. I can flash whatever is on the screen on & off at whatever rate I choose. Since I am not reading the status, I have to estinmate a delay that is needed by the HD61202 on the LCD. I shortened this delay for speedier operation and I may shorten it even more.

SUCCESS!!! An LCD IMAGE

larrykeegan — Thu, 09 Jun 2005 12:57:12 +0000

After much effort, I have made my HELLO WORLD pgm on a graphic LCD.
ALLELUJAH !!!

AN LCD (LIQUID CRYSTAL DISPLAY)

larrykeegan — Fri, 03 Jun 2005 09:05:48 +0000

HERE IT IS!

I have set about programming a graphics type liquid crystal display. It’s specs are 128 X 64. The RAM memory on the device is like a bit map of the display.
The one’s and zeros in memory make up the picture displayed.
I haven’t gotten it to work yet , but the hardware and wiring have been completed.

My first program did not do what I wanted and I may not have the correct command protocol for putting my data into the RAM memories. But I am confident I will find the info I want. Stay tuned!
UPDATE ! JUNE 4, 2005
Great news! I looked up the specs on the HD61202u which is called a
DOT MATRIX LIQUID CRYSTAL DISPLAY COLUMN DRIVER
and found that the controls and data bus go directly to these
chips – there are 2 of them -
also, the “instructions” or what I have been calling commands
are identical to what I have been using in my software.
But then, why is my display not working?
The program looks correct , so now the only lines I haven’t checked for continuity are pins 1 thru 6. These are control pins including
enable,r/w, d/i, and rst. Aso I will check the 2 select lines, selecting one or the other of the above mentioned driver chips (HD61202).
The 2 chips actually say SAMSUNG N044A but these must be exact replacements
since the specs given me with the chip explicitly say HD61202.
I felt very good though in finding out that I was using the correct instructions or commands.
Those commands by the way are
- display on/off
- display start line
- set page (x address)
- set Y address
- status read
- write display data
- read display data
Note that for a graphics LCD there are less commands than for an alphanumeric LCD, which I will be programming very shortly ( I just received 2 in the mail).

A VOICE RECORDING CHIP

larrykeegan — Mon, 17 Jan 2005 20:37:25 +0000

Well here it is! My setup for experimenting and building a project for the ISD2560 voice recorder chip.

You can see the cleaned up counter-top where I have assembled modules for the ISD2560 voice recorder chip itself, a PICmicrocontroller which talks to it, a
microphone card and an assembly for the loudspeaker output.

My main project is a device that will count up numbers and say the count out loud. “ninet million, two hundred thiry four thousand, two hundred twenty two”
“nine million, two hundred thirty four thousand, two hundred twenty three” etc., etc. Capacity is 99,999,999.
But what about the voice recording chip? Well it has a capacity of 60 seconds of recording. The main capability of the chip is that the digitally recorded sound messages are ADDRESSABLE. I can record multiple messages, like “one”
“seventeen” “thousand” and the by a variety of means, I can play indiviual
messages in any order I want. I also program my PIC microcontroller chip to send control signals to the sound chip. Sound like fun? Well, it is rather challenging to do, but I am enjoying every moment of it.

TWO ROBOTS !

larrykeegan — Sun, 02 May 2004 20:26:15 +0000

Here they are ! 2 robots
the one on the right I call the SQUARE.
It goes in a straight line and turns to the right.
It repeats this, traveling in a square.
The robot on the left is called the LIGHT-SEEKER
It will rotate and search for a light source. When it finds it, it will beep and flash and head toward the light