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This project is courtesy of Jim White via the rec.models.rc.helicopters newsgroup. Futaba sells this CAMPAC for around U$70 . This will increase the model memories to 16 and you can take the module out and plug it into another 8UHx. It's also a great place to backup the heli setup that you've been working on so hard. Jim "the MAN" White discovered that you can make your own with easily available components and some solder skills. The best part is that the total parts cost is about U$10. Yes, TEN dollars! Now this is not a project for first time soldering iron wielders. The pain is that stupid 7 pin connector hidden in the top of the Tx where the CAMPAC plugs in. It's very small so the CAMPAC connector is a pain to solder. Here is the original text by Jim White:
Call DigiKey at 1-800-344-4539 and order the following:
Note that Digikey charges a U$5 fee for orders under U$25.
PN / Description / Price / Quantity
V1043-ND / Vector Board / U$5.43 / 1
24LC16B/P-ND / Serial EEPROM / U$1.31 / 10
SPE1026-ND / 2mm Connector / U$1.34 / 10
10KEBK-ND / 1/8 W 10K Res. / U$0.28 / 20
The vectorboard is 4.5 x 6.5 and will make several campacs, or cover several mistakes !! The 10k resistors come in a minimum 5 pack....
First, the connector specified is a surface mount type, and needs to have the pins straightened out - you'll find every other pin bent 90deg to the body in alternate directions, just straighten them all out... then use an xacto and guilotine off the eigth pin of the 8 pin connector to make it into a 7 pin unit....
Cut a piece of the vector board (along the holes - it'll snap easily on a sharp table edge) to 1.2" x 0.9".... align the connector centered along one of the .9" edges of the board, with the pins toward the inside of the board, the entry edge of the connector even with the edge of the baord.... then SPARINGLY apply a few drops of CA to hold it in place... lets call the side of the board with the connector attached, the "back" side.... hold the board with the connector facing left, viewed from the "back" side, and mark the lower left corner of the connector with a marker as pin 1.... put the serial eeprom on the board from the "front" side, with pin 1 located diagnoly opposite pin 1 of the connector, i.e. at the upper
right.... with 3 empty rows of holes between the eeprom and the connector... bend the pins outward to hold the eeprom in place.... take 4 of the resistors (you only need one) and cut the leads off next to the body.... throw away the resistors and keep the leads for wiring the eeprom.... solder wires as follows:
Connector Pin ----- EEPROM Pin
1 ----------------- No Connection
2 ----------------- 5
3 ----------------- 6
4 ----------------- 8
5,6 --------------- No Connection
7 --- --------------7, 1-4
Solder one of the 10k resistor between pins 6 & 8 of the EEPROM....
Solder the other 10k resistor between pins 5 and 8 of the EEPROM....
That's it !!! If you look down into the Campac cavity, you'll see a white arrow near the pin to the right, that's pin 1.... plug your campac in with your previously marked pin1 aligned with pin 1 of the transmitters connector.... when you turn on your transmitter it will ask if you want to initialize the external memory.... just hit the "+" key and off it'll go.... after initializing, you'll see "Pac" next to the word "Model" at the upper right of the display.... enjoy.....
Jim White
AMA 2466
WB2WOY
WPMPA/BCF/PFC
SouthShoreSoftware
Treasure Island, FL
Schematic Diagram for the CAMPAC.
Parts Layout diagram for the CAMPAC.
My own assembly tips:
Order double the amount on connectors, you will mess up several. Get about 5 of each, build some for your friends.
You don't need to cut off the eight pin on the little connector. Just offset to one side.
The only pins needed in the connector are 2, 3, 4 and 7. You can remove 1, 5, 6 and 8 for easier insertion.
Pull the pins that have the solder tap on top and flip them so the tap is on the bottom. Easier to solder and harder to break off.
After testing the module seal the unit with epoxy. Take care, the Tx pins stick out of the back of the connector body about 4mm. Don't block the back of the connector.
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