 chips can be made by burning the ORB software onto Microchip
one-time-programmable (OTP) parts with a device called a programmer. This
section will describe simple steps to produce chips. There are other methods
and other vendors that can supply the equipment, and the method given is
not appropriate for high volume production.
Step 1. Procure the blank chips and a programmer.
Any Microchip PIC12C671 series chip will produce a working ORB, but two parts
are recommended for their low power consumption and wide operating temperature
range:
| PIC12LC671-04I/P |
|
Plastic DIP |
| PIC12LC671-04I/SM |
|
Plastic 208 mil SOIC |
The DIP part is used for through-hole soldering or socketed
applications, and the SOIC part is used for surface mounting. For software
development a windowed ceramic part is recommended because it can be erased
and re-programmed.
A good programmer is the Microchip PICSTART
Plus. It is not the least expensive, but its ease of use and integration
with the Microchip MPLAB development environment make it a reasonable choice.
The part number of the latest version is PICSTART-16B1.
Pioneer Standard
is a distributor for all three parts. The chips are about $2 each in small
quantities and the programmer is about $200.
For surface mount parts a programming adapter is also
required. A good choice is the 20SO21-D6-ZL from programming-adapter.com
for about $65 each.
Step 2. Install the software on a PC.
The MPLAB development environment is included with the programmer, or it can
be downloaded from the Microchip
website. The ORB Release 1 Software can be downloaded
from this site, and unzipped to a convenient directory. Only the rel1.hex
file is required to burn chips.
Connect the programmer to a serial port and verify that
is communicates with MPLAB application. Do this by Choosing the "Picstart
Plus" menu, then the "Enable Programmer" menu item.
Step 3. Burn the chips.
Put the chip in the programmer and flip the lever to positively connect it,
ensuring that Pin 1 is in the correct position.
Choose the "File" menu then the "Import>" menu item
and the "Import to Memory" menu item. Select the rel1.hex file from the location
where it was unzipped in Step 2. Press "OK."
Verify that the Program Memory Window looks like this.
Also verify that the Configuration Bits window looks like this. It should
be set from the .hex file, but if not set it manually.
And check the PICSTART Plus Device Programmer window.
When everything is correct press the "Program" button. After a few seconds
it should warn that calibration memory was not written (for non-windowed parts)
and announce that programming is complete.
Most applications will test the chip in use, but it
may be useful to test it before installing it. Contact APA Consulting for
assistance with testing. Over 1000 chips have been programmed with only one
failure.
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