AVR Butterfly Carrier - Parts Kit
ECROS Technology can supply a complete kit of parts to assemble your Butterfly Carrier, excluding the AVR Butterfly itself. The AVR Butterfly can be obtained from Atmel distributors such as Digi-Key and Mouser. The contents of the ECROS Technology kit is shown in the table, below.
IMPORTANT - To delay a price increase, Butterfly Carrier Parts Kits will soon ship with a different 3.3 volt regulator. Capacitor C2 is not required and not included in the kit, although you can use a capacitor in this position if you like. Capacitor C3 is also not included and must not be used. The new regulator has no minimum load current requirement, so there is no need to install R1 and LED1.
| Qty. | Description | Ref. Des. | Comments |
|---|---|---|---|
| 1 | Power Jack, 2.1 mm center pin | J2 | Center pin must be positive supply |
| 1 | Rectifier Diode, 1N4006 or similar | D1 | Protection against reversed supply voltage |
| 1 | 100 µF, 16V Electrolytic Capacitor | C1 | Input smoothing, may be omitted |
| 1 | 0.33 µF Ceramic Capacitor | C2 | Required by some regulators for stability |
| 1 | 3.3 V, 100 mA Regulator, TO-92 | Q3 | For higher current, use a TO-220 regulator instead |
| 1 | 0.1 µF Ceramic Capacitor | C3 | Required by some regulators for stability |
| 1 | 220 µF, 10V Electrolytic Capacitor | C4 | Output smoothing, other values OK |
| 1 | 220 ohm, 1/4 W, 5% Resistor | R1 | Current setting for power indicator LED |
| 1 | LED, 3 mm, Green | LED1 | Power indicator, DO NOT OMIT! (see Note 1) |
| 1 | Tactile Push-Button Switch | SW1 | Reset switch for AVR Butterfly |
| 1 | DB-9 Female Connector, PCB Mount | J1 | For AVR Butterfly serial interface |
| 3 | 2 row by 5 pin 0.1" Pin Header | J3 and Q1 | JTAG and Port B headers (see Note 2) |
| 2 | 2 row by 5 pin Header Socket | Q1 | JTAG and Port B header sockets |
| 2 | 2 row by 3 pin 0.1" Pin Header | J4 and Q1 | ISP header |
| 1 | 2 row by 3 pin Header Socket | Q1 | ISP header socket |
| 1 | 1 row by 10 pin 0.1" Pin Header Strip | Q1 | USI, UART and V+IN headers (see Note 3) |
| 1 | 1 row by 2 pin Header Socket Strip | Q1 | V+IN header socket |
| 2 | 1 row by 4 pin Header Socket Strip | Q1 | USI and UART sockets (see Note 3) |
Note 1 - Some voltage regulators need a minimum load current to be drawn in order to function properly. On the Butterfly Carrier, the power indicator LED draws about 6 mA and serves this purpose. If you omit the LED or R1, the AVR Butterfly on its own will not draw enough current for the regulator to operate. This may damage the AVR Butterfly.
Note 2 - Q1 is the AVR Butterfly itself. Two 2 by 5 pin header / socket pairs are for connecting the JTAG port and Port B of the Butterfly down to the Carrier. One 2 by 3 pin header / socket pair is for connecting the ISP port of the Butterfly down to the Carrier. No header / socket is supplied for Port D as on the AVR Butterfly this is connected to the LCD and is therefore not very useful for expansion.
Note 3 - The 1 row by 10 pin header strip should be cut up to make 4-pin, 3-pin and 2-pin headers for connecting the USI, UART and V+IN ports of the AVR Butterfly to the Butterfly Carrier. The header strip just snaps or cuts with a utility knife. One of the 4-pin socket strips should be cut down for the UART connection. Pull out the end contact and cut away the excess plastic housing with a utility knife.
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this button to go back to the Butterfly Carrier introduction.
Assembly of the Parts Kit to the PCB
It should take 30 minutes to an hour to assemble the supplied parts kit to the PCB, depending on how quickly you work. The recommended order of assembly is as follows (this is based entirely on component height so that turning the board over and putting it down holds things in place while you solder):
- Start with D1, C3 and R1 and the links for the serial port
- C2, LED1 (anode to R1, cathode to ground plane) and then the regulator, Q3
- J3 and J4, then the Port B and ISP headers for the AVR Butterfly
- At this point, assemble the Port B and ISP header sockets to the Butterfly
- USI, UART and analog input headers and sockets (if you put the Butterfly on the carrier with these single-row headers and sockets in place on both parts it will keep them straight while you solder)
- The AVR Butterfly JTAG header and socket and the power jack, J2
- Electrolytic capacitors C1 and C4 (make sure the polarity is correct)
- Finish with J1 and SW1, which snap into place
Please refer to the Assembly Tips for general information, not specific to the Parts Kit, and some more suggestions on how to put together and use your Butterfly Carrier.
Suggested Arrangement of Headers
The AVR Butterfly connects to the Butterfly Carrier via header / socket pairs. You can put either the header (male) or the socket (female) on the Carrier and the other half on the Butterfly. If you have no particular reason for a different choice, the following arrangement is suggested:
- The ISP and JTAG ports at the rear of the Butterfly Carrier should be pin headers (male) for compatibility with Atmel and third-party ISP and JTAG interfaces.
- For the JTAG port between the Butterfly and the Carrier, the socket (female) can be assembled to the Carrier, requiring you to mount the pin header (male) on the Butterfly. If this is done, the Atmel JTAG ICE can be connected directly to the AVR Butterfly, should you ever decide to do this.
- For all other ports between the Butterfly and the Carrier, the pin header (male) can be assembled to the Carrier, requiring you to mount the socket (female) on the Butterfly. The pin header is the cheaper and more readily available part so putting it on the Carrier makes it easier to use your AVR Butterfly in multiple projects on multiple Butterfly Carriers.
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Click this button to see a photograph of an assembled Butterfly Carrier, without the
AVR Butterfly, showing headers and sockets in the recommended positions.
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Click this button to see a photograph of an AVR Butterfly with headers and sockets
in place ready for mounting on the Butterfly Carrier.
Wiring up the Serial Interface
To use a straight-through cable from the female DB-9 on the Butterfly Carrier to a COM port of a PC, you should link RXD to pin 3 of the DB-9 and TXD to pin 2 (see the red wires in the photograph). For a cross-over ("null-modem") cable, reverse these connections. Note that cross-over cables usually have female DB9s at both ends and so will not mate with the female DB-9 on the Butterfly Carrier. Therefore, a straight-through cable is recommended.
Click this button to go back to the Butterfly Carrier introduction.