Microchip PIC16F628(A) control software

Frequency range : 87.5-108MHz
Stepsize : 50kHz (Up/Down)
Feature(s) : scans faster in 'Set' mode through the frequency range when
either the 'Up' or 'Down' button is pressed for more then
3 seconds.
pressing the 'Up' or 'Down' button when the PLL is locked,
switches the backlight of the lcd 'on' or 'off'.
Note:
====

The layout of the 300 mWatts FM-broadcast transmitter has been created with sPRINT
Layout v3.0. You can get a Shareware copy at: http://www.abacom.de
The pcb outline is 108 x 72 mm (width x height), bitmap resolution is 600dpi.
Use FR-4 single sided photoresist epoxy pcb material for best results.

(*) When printing the layout, be sure to resize it!

(c)2005 Helix Inc. The Netherlands.

300 mWatts FM broadcast transmitter (87,5-108 MHz), 50kHz stepsize, dual-speed.
(Hartley oscillator version)

All component values are drawn on the .comp and .silklayer bitmaps, with the following
exceptions;

1.- mount a 10pF (1206 SMD-chip capacitor) between the base and collector of BC547
(this is the 'switch' transistor in the loopfilter section).
2.- L1 = 4.5 turns, 6 mm diameter, 1 mm CuAg, tap ¾ to 1 turn from ground (spaced)
3.- Cx = 3n9 (50µS) or 4n7 (75µS)
4.- JP1 = 2 pins header + jumper
5.- all 1uH and 0,1uH coils are ready-made molded type coils.


Notes

(*) not used
CuAg = silver plated copper wire
CuL = magnetwire, enameled copper wire
(Note: 1 mm CuL approx. equals to AWG18
0,3 mm approx. equals to AWG28)
(I) all diameters are measured from the inside of the coils

The green led indicates if the PLL is locked
The red led indicates if the PLL is not locked

(C)2005 Helix Inc. The Netherlands.


300 mWatts FM-transmitter display connections and pinout 14- boxed header

v

13 11 9 7 5 3 1
O O O O O O O

14 12 10 8 6 4 2
O O O O O O O

Connector 16F84(A) L.C.D.
16F628(A)

1 9 14
2 10 4
3 8 13
4 11 ęDownł button
5 7 12
6 12 ęSetł button
7 6 11
8 13 ęUpł button
9 (ground) 5 5
10 (ground) 5 1
11 (+5 volt) 4, 14 2
12 (+5 volt) 4, 14 3
13 2 6
14 1 15 (backlight, pin 16 is connected to ground!)

Note:
Mount a single wire from the lcd (pin 2 or 3), this is the positive supply
for the pushbuttons (in case you panelmount them).

1 x 16 character display pinout:

1 = GROUND/ 0 VOLT
2 = POWER SUPPLY 5 VOLT
3 = SUPPLY VOLTAGE LCD DRIVER
4 = RS , REGISTER SELECT, LOW=INSTRUCTION, HIGH=DATA
5 = R/W, READ/WRITE, LOW=MPU to LCM, HIGH=LCM to MPU
6 = E, ENABLE
R/W=Low : Data are takingover at falling edge
R/W=High: Data can be read at E=1
7 to 14 = DB0-DB7, Data Bus software selectable 4 or 8-bit mode
15 = LED + (Anode of LED Unit)
16 = LED - (Kathode of LED Unit)

chomik by romano-wodzu