Altitude Encoder
Serial-to-Parallel Converter
for the Dynon Avionics EFIS-D10A
as
of: 23 Sep 2004
Schematic (382 kB)
This is a JPEG image of the schematic of the Encoder Converter so you
can determine the complexity of the project without downloading
anything further. Note that the 7806 regulator (U6) and capacitor
C14 are not needed here; I use this same PCB (with different firmware)
for another project -- an RC model airplane servo controller used for
electric trim in my Long-EZ.
Schematic and PCB Layout Diagrams
(67 kB)
This ZIP file contains everything needed to send to ExpressPCB to produce a circuit
board. Note that there are no Gerber files; ExpressPCB uses a
proprietary format. You will need to download ExpressPCB's free schematic
and PCB design software in order to view these files. Using that
software you can view and modify the schematic diagram and all of the
PCB layers (top, bottom, and silkscreen).
Firmware
version 1.02 (.HEX) file (15 kB)
This is the actual firmware for the Encoder Converter microprocessor's
flash memory. Select your browser's "Save it to disk" option when
downloading it. You will need a device capable of programming an
Atmel ATmega8 microprocessor (I use the Atmel STK-500 which is
available from DigiKey).
Installation documentation (1.5 MB)
This is the
documentation for installation and verification of the Encoder
Converter. It is not intended for construction but a
schematic diagram of the unit itself is
included in the appendix.
Schematic
diagram of an Altitude Encoder Tester
(240 kB)
This is a device you can build to display and check the output of the
Encoder Converter (or any
parallel Gray code output altitude encoder such as the ACK A-30).
The input is parallel Gray code and the output is displayed on LEDs.
Mode
C encoder data
table
(25 kB)
This is a table showing the states of the output lines of the Encoder
Converter (or any
parallel altitude encoder) vs. altitude. It is used with the
Altitude Encoder Tester (above) for verifying
the output of an altitude encoder.
Application
program to update Encoder Converter's flash memory (121 kB)
This program runs on a Windows PC and updates the Encoder Converter's
firmware if/when necessary. Its use is optional but if used, it
requires that bootloader firmware be programmed into the ATmega8
microprocessor and the appropriate fuses set. When I
assemble the Encoder Converter, I program the bootloader into the
microprocessor in my STK-500, connect the Encoder Converter to the PC,
and flash its firmware with the Encoder Converter's firmware.
Contact me for the bootloader hex file and fuse settings.
Joe Dubner
jdubner at
yahoo.com
