Monthly Archives: October 2013

Basic Perf-board Mega1284

???????????????????????????????Sooner or later, one finds the need to move the project from the breadboard to a more permanent setting.  There are development platforms like the Arduino Uno, Mega2560 with stackable shields, or you may want to just wire one up on a through-hole perf-board.  The layout of most development boards are certainly enticing, some projects require a little more flexiblity that stripboards and perf-boards can provide.  For low power applications strip-boards and perf-boards really handy for leaving the regulator off for low power battery performance and then later, adding a regulator.  The lack of inexpensive Mega1284P development boards make the perf-board an easy choice.Perf-board

The kit you will need for the Basic Perf-board Mega1284 is as follows:

  • (1) – ATMEGA1284P
  • (1) – 40 Pin IC Socket (wide)
  • (1) – 54 x 28 0.1″ spacing perf-board
  • (1) – 16MHz Crystal
  • (2) – 22pF ceramic capacitors
  • (3) – 100nF ceramic capacitors
  • (1) – 100uF 16-25 volt electrolytic capacitor
  • (1) – 10K ohm resistor
  • (1) – 1 x 6 pin header
  • (10) – Feet of 30 gauge stainless steel wire
  • (1) – DPST momentary switch
  • (1) – USB2TTL FTDI convertor

The first thing to note about perf-boards is that the solder pads can pull up if the solder iron is applied too long (around 10 seconds).  If you are not melting solder by 5 seconds, you will need to stop or you may damage the pad.

Step 1 – Placing and Soldering the IC Socket

Cut out 1 inch of the 30 gauge wire and connect pin 10 (VCC) to pin 30 (AVCC)

Place the IC Socket over the connection wire

Solder up the 40 pin IC Socket

On the backside of the perf-board, solder a piece of 30 gauge wire connecting pin 11 (GND) to pin 31 (GND)

Cut out 4 inches of 30 AWG wire and solder one end to pin 10 (VCC) and thread out to make connection with FTDI Vcc

Cut out 4 inches of 30 AWG wire and solder one end to pin 11 (GND) and thread out to make connection with FTDI GND

Place and solder a 0.1uF ceramic capacitor across pins 10 (VCC) & 11 (GND)

Place and solder a 0.1uF ceramic capacitor across pins 30 (AVCC) & 31 (GND)

Place and solder a 0.1uF ceramic capacitor across pins 32 (AREF) & 31 (GND)

Step 2 – Connecting the Crystal

Place the 16 MHz Crystal where one leg will make a straight connection to pin 12 (XTAL2)

Cut a piece of 30 AWG wire to connect the other leg to pin 12 (XTAL2)

Cut a piece of 30 AWG wire to connect the other leg to pin 13 (XTAL1)

With one of the 22pF ceramic capacitors, connect the lead between the Crystal and XTAL2 to GND

With another 22pF ceramic capacitor, connect the other lead between the Crystal and XTAL1 to GND

Step 3 – Connecting Reset and UART Communications

Cut out 4 inches of 30 AWG wire and solder one end to pin 9 (RST) and thread out to make connection with FTDI Reset three holes short of connecting to the reset pin on the header

Thread a 0.1uF ceramic capacitor lead into the same hole the 30 AWG (RST) line and solder

Thread the other lead and continue to connect to the FTDI Reset pin

With a 10k ohm resistor connect the 30 AWG (RST) line and 30 AWG (VCC) where close by

Place the DPST momentary switch to connect the 30 AWG (RST) line and the Ground (GND)

Cut out 4 inches of 30 AWG wire and solder one end to pin 14 (RXD0) and thread out to make connection with FTDI Tx

Cut out 4 inches of 30 AWG wire and solder one end to pin 15 (TXD0) and thread out to make connection with FTDI Rx

Step 4 – Finishing Up

Connect a 100uF/16-25V electrolytic capacitor on the 30 AWG (VCC) and (GND) lines (Negative on Ground).

Place an LED by pin 19 (Arduino D13) with the flatted side (Cathode) towards Ground and solder a lead from the Anode to pin 19

Place a 460 ohm resistor between  the LED Cathode and Ground then solder the LED to the Resistor and the Resistor to Ground

Place the ATMEGA1284 microcontroller into the socket

Connect the FTDI

If the ATMEGA1284 is freshly bootloaded and everything is connected correctly, the LED should flash.

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