Sonoff 4 Channel Pro

I have had an Amazon Dot for a while and use the interactive plugs and lights all the time, one of the plugs is for my Ham Radio PSU, so I have been looking for a relay interface which will work with the Amazon Dot, one of the key requirements is that the relays must be able to pulse on then off.

The Sonoff 4Ch Pro costs ~£25 and has 4 programmable relays including the ability to ‘inch’ a relay (pulse on then off), the reason this is important for me,  is that it allows a momentary trigger to the PLC controlling my automated mast.

The Sonoff 4Ch Pro is well made and can be powered from either the mains or 5 – 24v DC, relays are all voltage free.

The Sonoff App is EWeLink and allows direct control of the relays from anywhere, this App is then linked to the Amazon Alex App to allow voice control of the relays,m if you want to use voice control from your smartphone, Reverb is good.

EWeLink App needs an account setting up, once this is done, follow the instructions to pair with your router.  The default pairing LED flashing sequence did not work for me, I had to keep my finger on a relay button until the blue LED rapidly flashed and then followed the instructions.

Once paired, the blue LED remains steady, after a power down, WiFi locks within 20 seconds.

Sonoff Enclosure

I decided to mount the Sonoff 4Ch Pro in a 220 x 150 x 96mm ABS enclosure (£9.70 eBay), in Visio I drew the cutting stencil and transferred this to the enclosure.

The width of the Sonoff needing trimming slightly to make a snug fit, the get the correct height I packed the unit with 25 x 25mm wood off-cut.

Using a Dremel equivalent, the lid was cut to accept the Sonoff.

The IEC plug and socket stencil was attached to the side of the enclosure, using a scalpel, the cutting pattern was transferred.

Wired Sonoff 4Ch Pro, Relays 1 & 2 momentarily switch +24v as a trigger input to either Raise or Lower my mast, Relays 3 & 4 latch to supply individual IEC outlets.

The Relays and outlets are rated at 10A, the feeding plugtop has the appropriate fuse fitted.

Finished unit tucked behind a PSU, LEDs show that Relay 3 is energized and WiFi is connected.

The label below is the remind instructions on the voice commands (prefixed with ‘Alexa’) and how to change the relay names.

Update –

Had a huge headache trying to get this unit to re-pair once I had done some modifications to my home network and access point, looking through the help forums a large number of others are having the same problem, the solution which worked for was to put the iPhone in ‘Airplane Mode’ and follow the process to pair an Android phone (Touch) and not AP which had worked previously. What didn’t help was an unannounced outage of the European Sonoff servers!

The second issue which came to light was relay 4 would randomly operate, the fix was very simple, press and hold the internal S5 button to erase any pre-enabled RF switches.