ILER-DDS V2.1 VFO/DDS.
Page 9
RECOMMENDED ASSEMBLY SEQUENCE
I strongly recommend that you install the parts in the following order:
1. Resistors. All resistors are placed vertically. R4 is an adjustable resistor, insert it as shown in the
picture.
2. Capacitors. C2 and C8 are electrolytic capacitors, the longer terminal is positive. There is a "+"
printed on the PCB.
3. Crystal. Open its legs carefully and insert it into the PCB.
4. IC socket for IC2. Note that the "u" mark on one end must match that marked on the board
silkscreen. Ensure that it lies flat on the board.
5. Male and female terminal strips. Ensure that they are straight and flat to the PCB. There are four
female socket strips (two of 8 pin to be soldered to the LCD, and two of 10 pin for AD9850
module). In order not to be mistaken, observe the photographs carefully.
6. Voltage regulator. Place the 7805 IC1 and MCP1825S IC3 with its lettering facing the board.
Place to IC1 the small heatsink included with the kit, with the "U" facing outwards (see the cover
photo).
7. IC2. Insert the PIC18F2525-I/SP microcontroller into its socket..
8. LCD and DDS module. Insert the LCD and AD9850 DDS module into their respective sockets.
INSTALLATION
PIN FUNCTION
Marking
Function
uC bit
1
+12V
+12V
2
GND
GND
3
ENCODER_A
RB5
4
ENCODER_B
RB4
5
PULSADOR
RB3
6
AUX
RB2
7
AUX
RB1
8
TX INPUT (RIT) to GND on TX
RB0
9
AUX
RA4
10
S-METER INPUT
RA5
11
SINE WAVE OUTPUT B (from AD9850 module no LPF)
OUTB
12
GND
GND
13
SINE WAVE OUTPUT A (AD9850 module LPF built in)
OUTA
14
SQUARE WAVE OUTPUT B
SQRB
15
GND
GND
16
SQUARE WAVE OUTPUT A
SQRA
