[SOLVED] Problem with RF module interfacing to PIC micro Controller

bjuric said:

Do You mean that it never goes higher than 0,15V?
Datasheet says: "The output of the VT pin is high only when the transmission is valid. Otherwise it is always low."

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bigdogguru said:

Check out the:

Embedded Wireless Networks - WiFi, ZigBee, MiWi, 802.15.4, Bluetooth & RF

EWN - SubGHz/RF TX/RX Project Oriented Website Recommendations

I've posted several RF/PIC projects, some even use the HT12.

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Controlling the Project with a Microcontroller
Using these RF transmitter & receiver circuits with a Microcontroller would be simple. We can simply replace the switches used for selecting data on the HT-12E with the output pins of the microcontroller. Also we can use another output pin to select TE, or transmit enable on the HT-12E. By taking pin-14 LOW we cause the transmitter section to transmit the data on pins 10-13.

To receive information simply hook up the HT-12D output pins to the microcontroller. The VT, or valid transmission pin of the HT-12D could signal the microcontroller to grab the 4-bits of data from the data output pins. If you are using a microcontroller with interrupt capabilities, use the VT pin to cause a jump to an interrupt vector and process the received data.

The HT-12D data output pins will LATCH and remain in this state until another valid transmission is received. NOTE: You will notice that in both schematics each of the Holtek chips have resistors attached to pins 15 and 16. These resistors must be the exact values shown in the schematic. These resistors set the internal oscillators of the HT-12E/HT-12D. It is recommended that you choose a 1% resistor for each of these resistors to ensure the correct circuit oscillation.

You will need a few pieces of 22 gauge wire for the antennas on the RE-99 and TX-99. Both units come with full instructions for selecting the length of wire to use for each antenna. For a quarter wave antenna you will need 9.36 inches of 22 gauge wire for both the transmitter and receiver boards.

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FvM said:

There are basically two explanations:
- the module isn't receiving anymore, after the PIC is connected, e.g. due to interferences or any wiring fault
- the PIC is programmed incorrcectly and driving the respective pins low
You should be able to distinguish between both, but it's hard to see it from a distance.

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