This article describes the programming sequences for a common Chinese 315/433MHz remote relay which works with the common EV1527 transmitter.
The EV1527 should not be confused with high security protocols, the transmitter has burned into it four fixed supposedly relatively unique codes (in a space of 1 million code possibilities) and sends the burned in code associated with the transmitter key each time it is operated. This should not be confused with rolling code systems such as KeeLoq. This information is not usually disclosed by sellers.
These are usually supplied with little or no instructions, or bad online translations that are quite misleading. I dare say sellers have refunded money in lots of cases due to user confusion about programming them or compatible transmitters. This information might assist owners to find a working solution.
Above is an example remote relay (~$3 on eBay), they are available with a number of channels and may look physically different but use the same or similar firmware. Note that though the relay on this one is rated at 10A AC, that rating is for resistive load and it is rated at 5A AC for an inductive load (PF=0.4).
These would appear to have capacity for a very large number of learned keys, often advertised as capacity of 50 keys.
Programming
This information is for this specific device, there may be others that use the same firmware, or that look the same but use different firmware… this is “made in China”.
The structure of the EV1527 code is important. Each remote has a 20bit code followed by 4bits identifying the button. This binding means that there is some restriction on freedom to associate different buttons on a transmitter with different modes on the same receiver. The receiver processing of one button mode might override a condition already existing, eg a latched ON may be overridden my a momentary ON/OFF.
The multi-channel modules may work differently, they appear to use the button identifier to select the relay being controlled and the 20bit code is committed to the mode (ie a particular controller is committed to one mode and the buttons select the relay).
I make the observation that the firmware appears to have defects but to some extent this may be due to the interpretation of 20bit and 4 bit codes and the way in which it stores and searches codes, and resort to clearing the entire configuration may help in getting results.
There is a ‘LEARN’ momentary button on the PCB, it is used in concert with the remote transmitter to program the device.
The LEARN modes include:
- Momentary;
- Latching;
- Separate on button and off buttons;
- Delay – 5s;
- Delay – 10s;
- Delay – 15s;
- Delay – 20s; and
- Clear all.
Momentary
Press the LEARN button briefly once then wait for the LED to turn on and press the desired remote button and hold until the relay LED flashes rapidly to show programming complete.
Latching
Press the LEARN button briefly twice then wait for the LED to turn on and press the desired remote button and hold until the relay LED flashes rapidly to show programming complete.
Separate on button and off buttons
Press the LEARN button briefly three times then wait for the LED to turn on and press the desired ON remote button and hold until the relay LED flashes rapidly to show first stage programming complete and then the LED goes steady, press the desired OFF remote button and hold until the relay LED flashes rapidly to show programming complete.
Delay – 5s
Press the LEARN button briefly four times then wait for the LED to turn on and press the desired remote button and hold until the relay LED flashes rapidly to show programming complete.
Delay – 10s
Press the LEARN button briefly five times then wait for the LED to turn on and press the desired remote button and hold until the relay LED flashes rapidly to show programming complete.
Delay – 15s
Press the LEARN button briefly six times then wait for the LED to turn on and press the desired remote button and hold until the relay LED flashes rapidly to show programming complete.
Delay – 20s
Press the LEARN button briefly six times then wait for the LED to turn on and press the desired remote button and hold until the relay LED flashes rapidly to show programming complete.
Clear all
Press the LEARN button briefly 8 times in a row quickly. The LED with flash with the first 7 presses and on the 8th press it will clear the entire configuration (ie all learned keys). The LED will flash rapidly many times at completion.
Conclusions
These devices are very low cost, tend to be supplied with no information, or scant misleading / wrong instructions, and there are defects in the firmware (it is possible to get entries that are not overwritten for same key code), but with perseverence and liberal use of Clear All, they can be utilised successfully.