This chip has been used to create some simple and inexpensive modules that can be used to transmit and receive data using the 2.4 GHz band. The nRF24L01+ is the part number of a common chip used to construct 2.4 GHz transmitters and receivers, or “transceivers”. The one we will be playing with today is possibly the most popular, it’s available for a couple of dollars or less on eBay and Amazon. Channels 1 to 11 are legal in most every part of the world so you’d be advised to contain your experimenting to those channels.Īs communicating on the 2.4 GHz band is a pretty common function there are a number of modules made for exactly that purpose. Although there are 14 channels available not every one is legal in every area.
The band in question runs from 2.400.0 GHz to 2.483.5 GHz and in order to make it possible for multiple devices to coexist it’s broken down into channels.
Of course it also makes it perfect for a number of other devices in your house like wireless routers, cordless phones, Bluetooth gizmos and other wireless dodadds. The 2.4 GHz Industrial, Scientific and Medical (ISM) band has been reserved for unlicensed low-powered devices and this makes it perfect for building remotely controlled Arduino devices. There are plenty of frequencies available to experimenters like us, one of the most popular is the 2.4 GHz Band.
Using radio carrier frequencies illegally can result in a very stiff fine and is also pretty rude, so just don’t do it. In the United States it’s the Federal Communications Commission (FCC), in Canada it’s the Canadian Radio and Television Commission (CRTC) and in the UK the radio waves are regulated by the Office of Communications (Ofcom). Since these carrier waves can interfere with one another the allotment of them is strictly controlled, and every nation has a government department responsible for regulating them. On the receiving end the carrier wave is stripped off and the signal is “demodulated” to extract the original information from it. Radio signals are based upon the concept of changing or “modulating” a “carrier wave” that is transmitted wirelessly to a receiver. But they do serve their purpose in a number of low-speed data applications and are thus perfect or Arduino and Raspberry Pi experimenters who want to build remote controlled devices or who need to send data without wires. Radio waves are by no means a perfect method of communication, they are subject to interference from a number of sources and can be obstructed by metal or thick walls. Radio waves have a number of advantages over beams of infrared light, the most obvious is that radio waves can travel (to a degree) through walls and most other obstructions.
Signals are sent on beams of infrared light.Wireless devices are pretty well a part of our lives and most work using one of the following methods: We have been sending information wirelessly since the late 1880’s, Thomas Edison used a system of Electromagnetic Induction to send telegraph signals from a moving train to a set of wires beside the track. We’ll hook them up and use a very extensive library to facilitate communications between them.Īfter we get them working we will use them to build something fun – a wireless joystick control for the Robot Car Base that we worked on earlier.īefore we begin let’s examine the nRF24L01+ and some of the factore you need to take into account when designing wireless devices. The nRF24L01+ is available in a number of different configurations, in this article I’ll look at a couple of the more popular ones.
This band is free to use for low power devices without a license and in some cases can be useful up to a kilometer (although you should expect much shorter ranges without a special antenna). This is an inexpensive module that provides 2-way communications using the 2.4 GHz band. In this article (and in the corresponding video) I will examine one method of Arduino wireless communications, the nRF24L01+ module.