Assembling the RF Remote PCB for RS-485 Network

The assembly is straight forward and simple. Just make sure you have all the parts and a copy of the schematic (Circuit Diagram) on your table before you start to assemble the PCB. An assembled PCB should look like the PIC seen above. Schematic and Overlay of this project appear at the end of this document.

Please remember –

·        All resistors are 1/8 W type.

·        Use a proper relimate connector to connect the 4x4 Matrix keyboard to the Remote PCB.

·        The PCB has 2 Jumper links , start by assembling them , so that you do not forget them.

·        CN1 is the Power In connector, which has a reverse polarity protection diode. Use a 9V Box type Battery for power input.

·        Debug output is available on Pin# 15 of the MCU(IC). Connect a Serial Port Debug Connector to this pin and ground and check the output on a Terminal window @9600 baud.

·        D3 LED is activity Indicator and shows up when a key is pressed and data being transmitted.

·        D2 LED is a PWR On indicator, indicating Power available on Board. Although its good to have such an indicator, but if you are energy concerned/confident, then you can choose to omit this. This could say you some battery life.

·        The RF module works on 2.4Ghz frequency range and on 3.3V. I prefer the module assembled vertical on the PCB, but you can choose to assemble the Module horizontally to suit your requirement.

·        Components U2 and U3 are SMD type and are soldered on the component side of the PCB.

Starts off by assembling all the parts accept the RF module. You first need to get the connection between the Matrix Keyboard and the Controller PCB right. Keyboard connects at connector marked CN3 on the PCB, which is properly numbered for easy identification.

CN3 Ref.	Matrix Keyboard Ref.
1.      Black	C4
2.      Brown	C3
3.      Red	C2
4.      Orange	C1
5.      Yellow	R1
6.      Green	R2
7.      Blue	R3
8.      Violet	R4

After assembling both the PCB’s (less RF module) you can connect your debug pin to the Computer and check for proper key press. Check the activity LED indicator for proper operation on a key press.

Once you are sure of proper operation you can assemble the RF module and fire it up.

16 Keys RF Remote BOM
Sr.No.	Qty.	Ref.	Value
1	1	CN1	2 Pin Bergh Pin
2	1	CN2	4 Pin Bergh Pin
3	1	CN3	8 Pin Relimate Connector
4	1	C1	100uF/16V
5	2	C2,C3	100N
6	1	D1	1N4007
7	2	D2,D3	LED 3mm (1-Red, 1 - Green)
8	1	J1	JUMPER + Closer
9	1	M1	CC2500 + Right Angle Bergh pin
10	3	R4,R5,R9	470E
11	3	R7,R8,R10	2K2
12	3	R11,R12,R13	3K3
13	1	U1	16F1847
14	1	U2	1117-5V
15	1	U3	1117-3V3
16			18 Pin IC Socket
All resistors are 1/8W