Circuit 150 - 8-Channel RF Transceiver Circuit with PIC16F628 Application

As I said in the previous circuit149, this circuit (150) is part of that circuit, in fact, it is the added system for the radio command. In total, were built18 and sold for various automation. The circuit includes two boards, both with PIC16F628, one acts as a transmitter, while the other acts as a receiver. The transmitter circuit is very small, while the receiver circuit is a little larger if applied to circuit 149. The entire program of both microcontrollers is written in Assembly. For more details visit the dedicated article here.

Transmitter Circuit model WL102-341

Figure 1 - Transmitter Board

If we see the specifications of the modules, the transmitter is rated for 3.5-12V operation as input voltage and the transmit distance is 20-200 meters. It does transmit in AM (Audio Modulation) protocol at 433 MHz frequency. We can transfer data at a speed of 4KB/S with 10mW power.

WL102-341 transmitter module is UHF ASK modulated transmitters, support ASK and OOK modulation. The transmitter module integrates an analog PLL circuit and ASK modulation circuit, with a high level of integration, etc., can be applied with a short-range wireless communications. Operating frequency 433MHz, transmit power is greater than 11dBm.

Technical Features

1. Support ASK / OOK modulation, transmit power is greater than 11dBm;
2. Operating frequency: 433.92 MHz;
3. mains input voltage range: 2.0V-3.6V;
4. low-power consumption shutdown mode current is less than 1uA;
5. transfer rate up to 20KHz;
6. Launch distance :20-100 meters
7. Size: 16* 12 * 1 mm
8. external antenna: 25cm ordinary multi-core or single-core line
9. Temperature range: -45 to 85 °C

Firgure beow shows the electrical drawing with all details

Figure 2 - Electrical Drawing WL102-341

Receiver Circuit model WL101-341

 Figure 3 - Receiver Board

WL101-341 superheterodyne wireless receiver module is receiving UHF ASK demodulators support ASK and OOK modulation. The receiver module has high sensitivity (-110dBm), low power performance, along with high dynamic range (greater than 60dB). The module uses a highly integrated chip, built front-end low-noise amplifier, Mixers, filters, frequency synthesizer circuit, etc., can maximize the signal optimization.

Technical Features

1. Support ASK / OOK modulation, the receiver sensitivity of -110dBm;
2. Operating frequency: 433.92 MHz, bandwidth of about ± 150KHz;
3. Mains input voltage range: 3.0V-5V;
   Working current: Type :5.0mA (Requirement:VDD=5V) ;
4. Type :6.0mA (Requirement:VDD=3V)
5. Quiescent Current: 1uA
6. Low power consumption;
7. Good selectivity and spurious radiation suppression, and easy to pass CE / Fcc international certification;
   Good local oscillator radiation suppression, multiple receiver module to work with (ie, more than single income) and will not interfere with each other, used together without affecting the receiving distance;
8. Multiple transmission rates, the general module for 2KHz, up to 10KHz;
9. Temperature range: -40 to 85 °C
10. ultra-small size of 30.25 × 8.5 × 1 (mm) (can be customized according to customer)
11. External antenna: 32CM single core wire, wound into a spiral

 Firgure beow shows the electrical drawing with all details

Figure 4 - Electrical Drawing WL101-341

 Application

1. Wireless power switch, socket, remote control switch, receiver module,
2. Access control, electric cars, motorcycles, automobile anti-theft products, remote door openers, closers control system
3. Security, surveillance systems, home security products, electric doors, alarm host, alarm
4. Rooms controls, shutter doors, windows, remote control socket, remote control LED, remote audio remote control electric doors, garage door remote control, remote control retractable doors, remote rolling gates, sliding door
5. Smart home products, remote control curtains, remote MP3, audio

Antenna selection Description - General application mode

For general application mode ,the antenna can directly adopt the general specifications from the market;
The specific information as follows:

• The antenna’s core of conductor diameter(including the Antenna skin): 1.0mm,(except the Antenna skin): 0.5mm ;
• The wire length of weld end: 17.5mm, the wire length of antenna terminal: 9.5mm;
• The diameter of antenna winding (including the Antenna skin):5mm;
• The turn number of winding: 15 turns

For more details see Figure 5 below

Figure 5 - Antenna Drawing

The special enhancement mode of Antenna

The general application mode cannot satisfy if you need farther communication distance, so the special enhancement mode can receive farther communication distance, and the specific information as follows:
433Mhz Antenna

• The antenna’s core of conductor diameter (including the Antenna skin): 1.0mm; (except the Antenna skin): 0.35mm
• The wire length of weld end: 12mm
• The diameter of antenna winding (except the Antenna skin):3.0mm;
• The turn number of winding: 26 turns; The length of the winding: 36mm

For more details see Figure 6 below

Figure 6 - Antenna Drawing

Normally the antennas are built as shown in the Figure 7 and 8 below

Figure 7  - Antenna for Transmitter and Receiver

But this is not a standard, maybe with other manufacturers providing the same antenna for the receiver and transmitter, as shown in Figure 8 below

Figure 8 - Antenna for Transmitter and Receiver

Conclusion

This circuit is really special, thanks to the internal programs of the two PIC16F628 which encode a combined of 16-bit signal that is impossible to clone it. Furthermore, our internal program of PIC16F628 is protected from potential attackers, in fact, if the receiver, receives for 5 times a fake signal, in auto mode the internal program will go into protection, in this case, is required the reset or ACK of the receiver. Until not reset the device, the receiver will block all output. With the new update of circuits 149 and 150, it's possible to install the keypad with the buttons, and with the password you can reset the receiver.

The photo below show our remote control case

This circuit is recommended for automatic garage door opening, home or car security alarm, garden watering system, turning on the boiler, lights, etc. For further details on the program and the operating principle, do not hesitate to contact us, we provide all the necessary information