Replacement board for Gemini 7300 Car Alarm (only door remote control, no alarm)
I bought a second hand FIAT Seicento, previous owner installed
a 7300 Gemini Car Alarm system and it was not working at all.
7300 model is too old to get support from factory, too old to be repaired, and I've been searching a lot on the web to found replacement board (unsuccessfully).
I can buy a new cheap system from eBay, Amazon and so on, but I need to replace cables and connectors and I'm too lazy to do this.
I've found 7300 schematics on the web so.... why not make my
own board using 7300 cables and components?
I don't need all 7300 features, I just need remote control for
doors and blinking for direction indicators.
FIAT Seicento comes from factory with centralized door closing
system so I just need few electronics to add remote control
(mainly PIC microcontroller and RF receiver).
As receiver I use RX-4M HCS: AM (OOK) wireless receiver with integrated 4 channels rolling-code decoder
Aurel 433MHz
RF receiver with integrated 4ch decoder.
As transmitter we can choose between two options:
Aurel HCX-TX1
- 433MHz AM (OOK) rolling-code transmitter (here in 3 channel
version)
Aurel
TX3-HCS433-A - 433MHz AM (OOK) rolling-code transmitter.
PCB available as shared project on pcbway.com
And here final result:
I kept from original board 20 pin connector, relays and key switch.
I used PIC18F1330 (on image you can see wire as jumper, board
was originally born for different PIC model).
Now I update gerbers and PCB is ready for PIC18F1330.
Layout top:
Layout bottom:
BOM:
artlist exported at 24/03/2020 15:48:29
Part Value Device Package Description
C1 10uF CPOL-EUE2-5 E2-5 10uF - 25V
C2 100uF CPOL-EUE2-5 E2-5 100uF - 16V
C3 100nF C-EUC0805 C0805 100nF ceramic capacitor - 25V
D1 1N4004 1N4004 DO41-10 DIODE
D1A 1N4004 1N4004 DO41-10 DIODE
D2 1N4004 1N4004 DO41-10 DIODE
D3 1N4004 1N4004 DO41-10 DIODE
DZ1 15V-0.5W ZENER-DIODEDO41Z10 DO41Z10 Zener Diode
IC1 78L05Z L78L05ABZ-TR TO92 Positive VOLTAGE REGULATOR 5V
IC2 UA78L09 UA78L09ACPK SOT89 Positive VOLTAGE REGULATOR 9V
IC3 RX-4MHCS RX-4MHCS RX-4MHCS Aurel wireless - AM receiver RX-4MHCS with integrated rolling-code decoder
IC4 PIC18F1330 PIC18F1330-I/SO SO18W PIC microcontroller
ICD ICD_CONNECTOR ICD_CONNECTOR MA05-1 Strip 5 pin, pitch 0.1"
K1 V23072-C1061-A208 JJM2W-12VC V23072-C1061 DOUBLE MAKE CONTACT AUTOMOTIVE RELAY NAiS
K2 CV20 CV20 CV20 Relay CV20
KEY MS2000 MS2000 MS2126 Rotary switch Lorlin MS2126
LED1 LEDSMT1206 1206 LED RED
Q1 BC557BB BC557BB TO_92_BEN_PCB PNP Transistor
R1 3k9 R-EU_PCB 0207/10_PCB RESISTOR, 3900 Ohm, 5% 1/4W
R2 3k9 R-EU_PCB 0207/10_PCB RESISTOR, 3900 Ohm, 5% 1/4W
R3 3k9 R-EU_PCB 0207/10_PCB RESISTOR, 3900 Ohm, 5% 1/4W
R4 5k6 R-EU_PCB 0207/10_PCB RESISTOR, 5600 Ohm, 5% 1/4W
R5 560R R-EU_PCB 0207/10_PCB RESISTOR, 560 Ohm, 5% 1/4W
R6 5k6 R-EU_PCB 0207/10_PCB RESISTOR, 5600 Ohm, 5% 1/4W
R7 15k R-EU_PCB 0207/10_PCB RESISTOR, 15000 Ohm, 5% 1/4W
R8 120k R-EU_PCB 0207/10_PCB RESISTOR, 120000 Ohm, 5% 1/4W
R9 10k R-EU_M0805 M0805 RESISTOR, 10000 Ohm, 5% 1/4W
S1 31-XXDD ADTS32 OMRON SWITCH
T2 BC547BB BC547BB TO_92_BEN_PCB NPN TRANSISTOR
T3 BC547BB BC547BB TO_92_BEN_PCB NPN TRANSISTOR
T4 BC547BB BC547BB TO_92_BEN_PCB NPN TRANSISTOR
T5 BC547BB BC547BB TO_92_BEN_PCB NPN TRANSISTOR
T6 BC547BB BC547BB TO_92_BEN_PCB NPN TRANSISTOR
X1 5566-20R 5566-20R 353172020 Mini FIT connector 20 pol
Firmware:
file://http://crsengineering.altervista.org/sparetime/gemini_7300/PIC18F1330.hex