16 bit analog development
with a PIC 16F876
RJL Systems has a 25 year history in medical devices
and is proud to announce an analog development board
for engineers and hobbyists who demand accurate
signal processing for display and communications.
Bipolar 16 bit ADC (+/- 1.5000 volts FS 100K SPS)
Isolated 8 channel analog mux (single ended)
Isolated power supplies (+/- 5.0V analog and 5.0V digital)
Isolated 9 digital PIC I/O pins with buffered LED indicators
Hard wired development area with access to all power
Isolated RS-232C communications (115.2 Kbps max)
4 line X 20 character (blue) display with white LED
In-circuit programming and debugging (RJ- 12 connector)
CCS PIC-C sample code and schematics provided (CD ROM)
Operates from any battery or bench 6 to 12 VDC power supply
Screw terminals for convenient wiring to external devices
RJL Systems, Inc.
33955 Harper Ave.
Clinton Twp, MI 48035
Eight-bit RISC Microcontroller Data Book, Atmel Corp., 1999.
Xu, G.Y., “8X51 EPROM/Flash Microcontroller Programmer,” Circuit
Cellar Magazine, April 1998.
C: > AVRASM -I LED1AVR.ASM LED1AVR.LST
NUTS & VOLTS
This command generates a listing file LED1AVR.LST
and Intel Hex file LED1AVR.HEX, which is what we need
for programming and is shown in Listing 2.
To write AVR Flash memory, first press ctrl-W, then go
to “Transfer” menu in Hyper Terminal, and click “Send Text
File.” Enter the file name LED1AVR.HEX in the dialog box
and press <enter>. In a moment, the text file transfer and
programming will take place and the progress is shown on
screen. Finally, you’ll see the “Programming Completed”
To verify the programming, use almost the same procedure as Writing, but — this time — first press ctrl-V and then
go to the “Transfer” menu and do the same “Send Text File”
process. Once you type in a text file name and press
<enter>, that file is sent to the programmer and compared
with the memory contents being read. If every byte comparison is okay, a “Verification Successful” message displays.
On some desktop or laptop computers, things may not
be going so well. If that happens, you may need to redo
something on the File menu. For example, if you can’t
program all bytes correctly or some bytes are shown as
missing when read, then you may need to go back to File >
Properties > Settings > ASCII Setup, and put a 1 millisecond
delay on both the Line Delay and Character Delay boxes.
Figure 4 shows how to physically hook up the
LEDAVR circuit to demonstrate your programming results.
This circuit can be mounted on a solderless breadboard.
We also provide another program called LED2AVR.HEX to
light up the same LED, but with a double blinking feature.
You can try it out after programming with LED1AVR.HEX.
You don’t have to hook up any circuits, though, just
use the programmer itself to demonstrate your success.
Note that both the 20-pin socket U2 and U3 have the same
Vcc and GND pins, in addition to the same Reset (pin 1),
Oscillator (pins 4 and 5), and LED connect, pin 11. So,
after programming, simply remove the AT89C2051 from
the socket and replace it with the programmed
AT90S1200/2313. Then, power-up and you’ll see the LED
blinking or double blinking. This feature of the program
saves you time and money. NV
About the Author
G.Y. Xu is an electrical designer specializing in microprocessor/
microcontroller systems design and development, both in hardware and
software. He can be reached by Email at firstname.lastname@example.org