Before asking a question or reporting a bug, please read Theory of operation Do not contact the author directly, unless it is to discuss commercial licensing. You can also find online help and disussion at Please use that group for all questions and discussions on this topic. The version of the package that this documentation refers to can be downloaded from You can find the latest version at

VirtualWire: unaddressed, unreliable messagesĮxample Arduino programs are included to show the main modes of use.They work a bit with ASK wireless, but not as well as this code. Messages are sent with 4-to-6 bit encoding for good DC balance, and a CRC checksum for message integrity.īut why not just use a UART connected directly to the transmitter/receiver? As discussed in the RFM documentation, ASK receivers require a burst of training pulses to synchronize the transmitter and receiver, and also requires good balance between 0s and 1s in the message stream in order to maintain the DC balance of the message. Messages are sent with a training preamble, message length and checksum. It is intended to be compatible with the RF Monolithics (Virtual Wire protocol, but this has not been tested.ĭoes not use the Arduino UART.

Can also be used over various analog connections (not just a data radio), such as the audio channel of an A/V sender All that is required is transmit data, receive data and (for transmitters, optionally) a PTT transmitter enable. Supports a number of inexpensive radio transmitters and receivers. VirtualWire is a library for Arduino, Maple and others that provides features to send short messages, without addressing, retransmit or acknowledgment, a bit like UDP over wireless, using ASK (amplitude shift keying). Nevertheless we recommend upgrading to RadioHead where possible. This library will no longer be maintained or updated, but we will continue to publish it for the benefit of the the community. All the platforms that VirtualWire supported are also supported by RadioHead. This VirtualWire library has now been superceded by the RadioHead library RadioHead and its RH_ASK driver provides all the features supported by VirtualWire, and much more besides, including Reliable Datagrams, Addressing, Routing and Meshes.

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