If you have Futaba transmitter, you should know about model memory extention
modules. Those are very convenient to backup model settings or to move settings
between transmitters. Memory extention modules a named CamPAC. There are 2
main module types on the market: CamPAC 16K and CamPAC 64K (they have different
memory capacity).
Many guys think, that original CamPAC-s are overpriced. So, you can prefer
to make the module youself. CamPAC 16K has very simple schematic. It's know
very well, and I'm not going to tell you evident deals once again. If you
are looking for CamPAC 16K info, just go to this page: http://www.ncws.com/rcrock/clonepac.htm.
I'm going to tell you about CamPAC 64K. My transmitter can understand only
64K-modules. I was very surprized to know, that nobody yet published CamPAC
64K plans in internet. So, I had to analyze data flow in original module to
make something suitable.
Archive contents:
| /readme_en.htm |
this file |
| /readme_ru.htm |
russian description |
| /mempac64.hex |
firmware for MCU |
| /mempac64.pdf |
PCB drafts (1:1) |
| /images/*.* |
images for this description |
| /gerber/*.* |
PCB gerber files |
MemPAC 64K for Futaba
Original CamPAC 64K has data exchange protocol almost the same as 24C16
serial EEPROM. The only difference is in the device addressing byte. If
you know, how 24C16 EEPROM works, you can be interested in description
of that byte:
| |
ID |
Address |
R/W |
| bit |
b7 |
b6 |
b5 |
b4 |
b3 |
b2 |
b1 |
b0 |
| value |
0 |
0 |
A12 |
A11 |
A10 |
A9 |
A7 |
R/W |
I've tryed to keep my schematic as simple as possible. Look the images below.
Original CamPAC 64K (left) and home-built MemPAC 64K (right). I think, that
right one is more simple.
MemPAC 64K has a single-side PCB, and it can be done in home conditions without
problems. For your convenience, here is PCB draft of 1:1 size: mempac64.pdf.
mounting draft
All resistors and capasitors - 0805 size.
EEPROM and MCU - by Atmel, in SOIC body. You can try to use Microcip EEPROM
PIC24LC64-I/SN or PIC24LC65-I/SN, but it's not recommended.
The only part, difficult to find, is connector with 2 mm step, with horizontal
mounting. But you can order it in Digikey (S2104-07-ND) or Farnell catalogs.
After you get all parts and PCB, you need to program microcontroller. I've
used AvReal to do that.
The command line for Windows version of AvReal looks like this: "avreal32
+tiny15 -p1 -ap -e -w -v -c campac64.hex -fboden=0,cksel=3".
If you prefer another programmer, keep in mind to set right MCU configuration
bits: boden=0, cksel=3.
WWW:
http://www.rcdesign.ru
Email:
vitaly@rcdesign.ru
Schematics, firmware and this description of "MamPAC 64K" are freeware. You
can use it for noncommercial purpuses and futher distribute, keeping integrity
of source archive and all files included. Any commercial use without author's
permission is prohibited.