So what is EV1527 and Learning Code?
EV1527 is a format of learning code receivers commonly used by radio frequency transmitters such as garage door remotes. The format was designed to allow a large keyspace (number of possible unique remote identifiers) and a practical number of possible channels on each remote while still remaining cost effective.
To put it simply, learning code systems have fixed codes assigned to each remote (which do not change). These codes are then learnt into the receiver which allows them to change the state of a relay. This learning function is usually performed through a button on the receiver being held down while pressing the desired button on the transmitter.
The EV1527 data transmission format uses the following layout to identify the remote and buttons:
Each bit can be either a 0 or 1 in value. Using 20 bits for identifying the remote allows 2^20 possible remote identifiers which is a little over 1 million. This means that there is a 1 in 1 million chance of another remote having the same identifier. For this reason, the EV1527 format is not used for high security applications.
The 4 bits for button identification are a great strength of the EV1527 format. This allows for 16 channels to be controlled through one remote transmitter. This feature is perfect for systems which require activation of many different relays via one remote.
These chip-sets can be found in devices ranging from 3V to 12V. It is important to note that the transmission distance of EV1527 chip-sets is limited by the voltage of the device.
EV1527 is often used in residential alarm systems, gate control and garage door controllers. When compared to traditional fixed code formats such as PT2262 (key space of 6561 unique addresses), EV1527 offers a much more secure and practical list of applications.
Higher security options
If EV1527 isn't going to make the cut for your setup, try a rolling code systems.