Plant watering Fiasco

As more technical people wake up to the folly of trying to use simple resistive DC plant moisture sensors, it seems the Chinese have latched onto the idea of capacitive sensing…

Capacitive sensor

And here it is, the sensor that is all over Ebay right now at am amazingly low £2 inc free shipping, that is until the UK rip-off artists get hold of it and at least double that price, which they’ve already done. If you are happy to sit over your plants waiting for a quiet “beep” – not quite so practical then, not to mention the constant supply of new battery pairs.

And definitely not to mention that the easily corroded batteries and active end are only an inch or two away from the waterproof, non-corrosive sensor end. Perhaps where the designers live the soil doesn’t move and there is no rain or snow.

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EleksMaker Pro Laser Engraver

After much delay and I have to say patience from Banggood, I am now putting together this A3 laser engraving machine. Nearly done and today, the actual 500mW module itself has arrived complete with its own power supply (the laser which was not included in the basic kit). Meanwhile, assembling the kit looked like a day’s work so I figured I’d better get on with it. Mechanics all done but at this point I’m not seeing how to dim the laser.


Essentially the unit comes as a well-packed set of 3 motors, various aluminium tubes, a host of pre-cut Perspex pieces and an unfeasible number of nuts, bolts, retainers, wheels and various spacers. I opened the box maybe 9am Friday morning and spent the rest of the day constructing.

At first it all looks a little daunting but that apprehension soon goes away, It did not take long to reach the stage where a whole table was needed to hold all the parts but by mid-day I’d cracked the back of this. I also broke one of the Perspex fastener/tensioners however.  Thank heavens for Gorilla glue. I hope it is strong enough. Seems to be up to now, days later.

Two of the three motors move the laser assembly forward and backward (left and right sides). The third motor is mounted with the laser and moves the latter left and right.

No documentation came with the unit but the Banggood site has construction info, software and drivers. What you see here are my own photos, in the link below, you’ll see the construction photos available, which I used to help me assemble the unit. The images in their docs are good but I was left in doubt as to where to mount the small electronic control box on the front aluminium support beam because other suppliers showed the box mounted vertically whereas in the Banggood-supplied revision, the box mounts horizontally. This box needs some trivial assembly which only takes a few minutes. I do not have detailed wiring information but it looks fairly simple. A power supply is provided. No info as to whether to mount this somewhere or leave lying on the bench (unless I missed something).  Similarly (now the laser is here) I’ve no idea where to put its supply but I’ll figure that out as I go along.

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Big Timer

tmp17DBBig Timer is probably the best timing node for Node-Red, providing a general purpose timer as well as  handling summer/winter correctly as well as (importantly) lighting up time (for which it needs longitude and latitude). After all you probably don’t turn the outside lights on at 6pm!! You turn them on when it gets DARK.

New: “toggle” mode. Now with new seconds timer mode AND updated for the latest Node-Red 0.17.5+ including new help formatting and tips on input and output.

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Big Timer Status

I occasionally get comments in the blog about people having problems with BigTimer, virtually all get resolved by users themselves and it is quite some time since BigTimer has actually had any problems, so for clarification, here it is working alongside Blynk, inject nodes and with MQTT. I am currently in the UK and it is currently 11.45am here in Blighty.

This particular timer is set to turn a light on at dusk and off again at midnight, unless manually overridden by an inject node or by Blynk (I’ve created a button on my phone which can turn on the output or restore it to auto).  I hope soon to have multi-state button as this has been introduced in Blynk (but I can’t get it to actually work (at least not using the local Blynk server).

Big Timer Status


Goodies from Inateck

In today’s postbag came three items from Inateck, namely a lovely small, well packaged Bluetooth plus aux input, a USB powered Bluetooth loudspeaker, completed with leads. The unit also supports a microSD card.

Also in the post from the same company, a tiny Bluetooth receiver/transmitter and a quality dual-phone mains charger (not to be confused with a simple USB hub which cannot provide any additional voltage for high speed charging).

Products from Inateck




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Deceitful Advertising

Sometimes I wonder what has happened to trading standards in the Internet age. Today it is apparently perfectly ok to lie through your teeth when advertising, particularly when you can later hide behind the language barrier.

See particularly bollocks advert here at AliExpress. They don’t do themselves or  us any favours allowing rubbish like this…

  5v 6amp means 30w, not 40w as claimed and how can the output be fixed at 5v when the unit also claims to support Quickcharge 3?  Utter waste of time.


The Script

Regular reader will know about the script that Aidan Ruff and I originally developed to put Node-Red and several other packages onto the Raspberry Pi for our own home control purposes. This has been developed with help from several people and in particular my friend Antonio.

The Script, ESP-GO and Nano Peripheral

WELL – here is the script which is intended to help set up certain Raspbian, Debian or similarly-based SBCs which now includes logging and handling Raspbian Stretch (tested on Raspberry Pi  2 and 3, 3B+). As well as it's original purpose of setting up a Raspberry Pi, the script also runs well with several other boards.  See right hand side of the above image for what the script does, given a basic operating system install. Read on…

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FY6800 Signal Generator

In today’s postbag, the new Feeltech FY6800 dual channel Signal Generator, complete with UK power lead, two bnc test leads, USB lead and bnc-bnc lead. However the unit came with no instructions or other paperwork. I assume a manual will follow later. The unit arrived well-packed via FedEx.


Lovely to look at and extremely comprehensive in operation, the FY6800 is a compact unit that belies the vast range of functions it handles.

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