SparkFun Support and Front Desk will be closed on Thursday 11/14 from 1-2:30pm for a company event. Please plan to pick up your orders before or after this timeframe.
These wireless transmitters work with our 434MHz receivers. They can easily fit into a breadboard and work well with microcontrollers to create a very simple wireless data link. Since these are only transmitters, they will only work communicating data one-way, you would need two pairs (of different frequencies) to act as a transmitter/receiver pair.
Note: These modules are indiscriminate and will receive a fair amount of noise. Both the transmitter and receiver work at common frequencies and don't have IDs. Therefore, a method of filtering this noise and pairing transmitter and receiver will be necessary. The example code below shows such an example for basic operation. Please refer to the example code and links below for ways to accomplish a robust wireless data link.
Note: Color may be blue or green, but they are the same module.
1 of 1 found this helpful:
To ensure that the RF links are working, we recommend trying to get the RF links working with our example code first. However, I have tested the RF modules with the VirtualWire librarie and Arduino 1.0.6 IDE software. I was able to get it working with this library => VirtualWire 1.20. This library worked with both Arduino 0023 and Arduino 1.0.6.
The example code used with the an Arduino microcontroller explains the setup for each RF Link. This is the setup which will work with either RF Link frequency band.
Transmitter Code (4 pin module)
Pin 3 of your Arduino should connect to pin 2 of your RF Link Transmitter 434MHz. Button is connected to the transmitting Arduino on pin 8 separate from the RF Link Transmitter. When a button is pressed on the transmitter, the corresponding LED should light up on the receiver and a character will be sent.
Receiver Code (8 pin module)
Pin 2 of your Arduino should connect to pin 2 of your RF Link Receiver 434MHz. When the button is pressed from the transmitter side, the corresponding LED on this side will light up on pin 8. One thing to note is that the associated LED will not light up on the receiver end if you do not have the associated character to check if it is what is received. An example is if you send a string of characters “Pin 4,” the receiver LED will not light up when the characters “Pin ” is sent. It will only light up when it sees the number “4”.
Note 1: It seems like when the receiver code is compiled with Arduino 0023 that the characters sent show a character and a space right after it in the serial monitor. When compiled with Arduino 1.0.6, you get an hex value and a space that is related to the ASCII character that was sent. You can verify it by checking the ASCII table and it will show that the hexadecimal value that was sent is indeed the character that was sent from the receiver. This has something to do with the shift in versions from Arduino’s 0023 to the Arduino 1.0 and above. Something was modified in the compiler or how a function was defined in the Arduino IDE.
Note 2: The RF Links are cheap wireless modules so you might get some intermittent data transmission/ corrupt data after a certain distance. They have a lot of noise. A better and more secure option might be to use the XBee Series 1 Wireless Modules.
Note 3: I am aware that the Virtual Library is EOL and that the RadioHead library supersedes it. I found out in the middle of updating the code. You shouldn’t have a problem with the library though even though it is EOL.
If a board needs code or communicates somehow, you're going to need to know how to program or interface with it. The programming skill is all about communication and code.
Skill Level: Rookie - You will need a better fundamental understand of what code is, and how it works. You will be using beginner-level software and development tools like Arduino. You will be dealing directly with code, but numerous examples and libraries are available. Sensors or shields will communicate with serial or TTL.
See all skill levels
If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.
Skill Level: Rookie - You may be required to know a bit more about the component, such as orientation, or how to hook it up, in addition to power requirements. You will need to understand polarized components.
See all skill levels
Based on 2 ratings:
2 of 2 found this helpful:
Paired with the receiver and two Arduinos, I went from knowing nothing about coding transmission signals to getting a wireless transmission between them; all within an hour. Works flawlessly with VirtualWire library. Reliable, easy to use. Very pleased with it!
I was designing a new remote for a gate and garage opener and wanted to keep things simple. After researching RF communication, I realized the main reason people were getting so little range from most RF units was the low power output of the transmitter. Most of these were using 5 - 10 mA. Sparkfun's transmitter uses 32 mA of output power as long as you feed it 12 volts. With just a straight piece of wire that was not the optimal length and using the Radiohead library, I was able to walk over 200 feet away communicating through a brick wall and still send a reliable signal. If I had a better line of sight, I'm sure I could have gone farther, but this was plenty far for what I needed. If you want a simple method of wireless communication and aren't worried about security, the 434 MHz transmitter and receiver while using Radiohead on an Arduino is a great solution.