Remote Control RF Modules.
Posted: Sat Aug 31, 2013 11:16 am
Introduction:
While browsing one of my regular component supplier websites the other day, I spotted these lovely little RF receiver modules.
They have 4 separate outputs, which can be (depending on the version of the board) latching or momentary.
They operate at 315 MHz, and a matching remote keypad is also available.
The Modules are under £5 each and the remote is £5.40
They use the PT2272-M4 (Latching) and SC2272-T4 (Momentary) devices.
The first thing I noticed when I received the modules, was that one side of the main IC was unsoldered.
The supplier confirmed all their stock was like this, and they were tested and working.
On closer examination, it was seen that the pads did not actually have any tracks to them.
The board was connected to a 5V supply, and 4 LEDs and resistors connected to the output pins and down to ground.
Pressing the corresponding key on the remote pad, caused the LED to light.
The range was found to be very good. I could get it to work with the module in the upstairs front and the remote outside at the back of the house.
One downside is the modules as they are supplied are not addressable so if you have more than one board, when you activate the remote, that pin will go high on all powered modules in range.
Though after looking at the data sheet, I believe the IC’s used are capable of being addressed, by means of the unconnected pins on the IC.
They can be obtained in the UK from
http://www.hobbytronics.co.uk
In the States, I believe they can be obtained from Adafruit.
Datasheets for the control devices can be found in various sites, including here.
Latching Board
http://www.adafruit.com/datasheets/PT2272.pdf
Momentary Board
http://www.sc-tech.cn/en/SC2272.pdf
Using With Microcontrollers:
Hardware
Custom 4 x 20 LCD Board.
EB006 Programming Board.
EB016 Prototype Board.
Jumper wires.
LEDs.
Resistor.
The module was connected to the microcontroller PORTA
Out 0 – A3
Out 1 – A2
Out 2 – A1
Out 3 – A0
5V and ground being taken from the EB006
The LCD display was connected to PORT B.
I used my custom board to enable more data to be shown.
A simple Flowcode program was produced to show the binary state of each pin on the display.
A fifth output pin (VT) is also available; this goes high when the received data is valid.
The line is only held high for as long as the RF signal is being received.
Conclusions:
This is not meant to be an in depth project, but just to share the concepts of a usable and inexpensive RF module.
A couple of example flowcharts have been attached using both FC5 and FC6.
Could be a future idea for a FC6 component.
The LED is connected to the VT and lights when a valid data pulse is received.
While browsing one of my regular component supplier websites the other day, I spotted these lovely little RF receiver modules.
They have 4 separate outputs, which can be (depending on the version of the board) latching or momentary.
They operate at 315 MHz, and a matching remote keypad is also available.
The Modules are under £5 each and the remote is £5.40
They use the PT2272-M4 (Latching) and SC2272-T4 (Momentary) devices.
The first thing I noticed when I received the modules, was that one side of the main IC was unsoldered.
The supplier confirmed all their stock was like this, and they were tested and working.
On closer examination, it was seen that the pads did not actually have any tracks to them.
The board was connected to a 5V supply, and 4 LEDs and resistors connected to the output pins and down to ground.
Pressing the corresponding key on the remote pad, caused the LED to light.
The range was found to be very good. I could get it to work with the module in the upstairs front and the remote outside at the back of the house.
One downside is the modules as they are supplied are not addressable so if you have more than one board, when you activate the remote, that pin will go high on all powered modules in range.
Though after looking at the data sheet, I believe the IC’s used are capable of being addressed, by means of the unconnected pins on the IC.
They can be obtained in the UK from
http://www.hobbytronics.co.uk
In the States, I believe they can be obtained from Adafruit.
Datasheets for the control devices can be found in various sites, including here.
Latching Board
http://www.adafruit.com/datasheets/PT2272.pdf
Momentary Board
http://www.sc-tech.cn/en/SC2272.pdf
Using With Microcontrollers:
Hardware
Custom 4 x 20 LCD Board.
EB006 Programming Board.
EB016 Prototype Board.
Jumper wires.
LEDs.
Resistor.
The module was connected to the microcontroller PORTA
Out 0 – A3
Out 1 – A2
Out 2 – A1
Out 3 – A0
5V and ground being taken from the EB006
The LCD display was connected to PORT B.
I used my custom board to enable more data to be shown.
A simple Flowcode program was produced to show the binary state of each pin on the display.
A fifth output pin (VT) is also available; this goes high when the received data is valid.
The line is only held high for as long as the RF signal is being received.
Conclusions:
This is not meant to be an in depth project, but just to share the concepts of a usable and inexpensive RF module.
A couple of example flowcharts have been attached using both FC5 and FC6.
Could be a future idea for a FC6 component.
- Module.jpg (41.44 KiB) Viewed 17736 times
- Protoboard.jpg (39.27 KiB) Viewed 17736 times
- Control.jpg (25.19 KiB) Viewed 17736 times
.)