INA3221 v INA219

tmp19F7Voltage and current monitoring

The INA3221 or rather one of the boards based around it, allows for a single power input and up to 3 power outputs –each monitoring voltage and current and all done via I2c.

You can (almost) think of this as a triple INA219 – the bidirectional current power monitor. If you recall, a little while ago, I added the INA219 to my ESP8266 software. I thought the INA3221 board might be better than three of the INA219 boards – but read on…

Continue reading INA3221 v INA219


A busy Week

It has been a busy week this week – with lots of new things happening.

Firstly, there is a brand new update to the RFLINK software, IMHO the best software around for decoding and transmitting signals for a wide range of RF devices – such as weather stations and remote controls – in my case using 433Mhz.  See the short video update I did on this one.

Here’s a link to a blog entry I wrote months ago on the same subject. tmpC114Then I’ve been working on the DPS5020 and DPS3003 power supply boards which have provided HOURS of entertainment.  I’ve spoken with the designer and I think this stuff has a good future because of the kind of direct support they are keen to give – and because the stuff just works. In a couple of weeks there’s a new board from the same source and when my new scope arrives I’ll be using that and the load tester to give it a hammering.

I’ve had a play with my little EM125 pocket (well, large pocket) oscilloscope and in the process of playing with these two, discovered the need for a decent signal generator and dummy load – both of these are on the way and will be covered in the coming weeks – along with some other exciting incoming stuff like a new 3D printer and a “proper” desktop scope.


MEANWHILE I’ve not gone off the boil with the uninterruptible supply, FAR from it but Aidan and I have been waiting for a PCB to turn up. It came earlier this week and we’ve been getting that working – of course, as you might expect, in the process of doing that we’ve thought of better ways of doing things, so the present PCB is going in the bin and a newer, smaller, better design will be forthcoming, most likely before Christmas.

Oh and not to  forget the new Alexa feature – using it as an Intercom – that is MARVELLOUS.

Lots happing in the next few weeks….so make a note to look in – or better, if you’ve not yet subscribed to the newsletter on the right panel of the blog) – please do!

A quick thanks to all of you who feed back constantly on the blog and on my videos and for all those who provide new ideas and new links – what a great time to be interested in technology.


DPS5020 and DPS3003 PSUs

DPS5020 Power supplyFirstly, the DPS5020 power supply comes in 2 parts, the main controller and a front panel. You get the pleasure of fitting it in a box – and supplying power. So it is “kind of” DIY.

In this case you get a programmable power supply able to give you up to 50v at up to 20 amps output.

But doesn’t that seem a bit daft, needing a power supply to feed a DIY power supply? Nowhere near as daft as it seems – read on – it gets a lot better…

Continue reading DPS5020 and DPS3003 PSUs


EM125 Handheld Scope

tmp696AIt was just like Christmas this morning. After a few days of no posty, a couple of packages turned up for me. Inside one of them, the EM125 Handheld Digital Oscilloscope. This large-pocket-size scope runs for up to 10 hours on an internal rechargeable batteries, has 25Mhz bandwidth and also acts as a voltmeter, diode and capacitor tester and resistance checker.

Continue reading EM125 Handheld Scope



For some reason this morning when I got up – there were more emails than usual – and amongst them – sales – so here’s just a quick set of links – in case you’re after some Christmas presents for yourself Smile  = I’m not saying they are good or bad, just pointing you in their direction just in case. Last week I got a hell of a good new phone cheap in the Banggood sale (and I’ll be on edge until it turns up in a couple of weeks) so sometimes there are bargains to be had.

Anyway, here they are – if you’re aware of more so called “Black Friday Sales” of note, do let us know (no, they didn’t ask me to do this)

eGlobal Central Pre Black Friday SaleGeek Buying Black Friday Sale, Banggood Black Friday Sale.


Node-Red and Alexa with Big Timer

tmp96D4I’ve recently updated my setup at home, finally doing away with HA-Bridge and I thought you might like to see this simple setup.

So for beginners, HA-Bridge is a piece of software (a very nice piece of software) that runs on for example a Raspberry Pi, who’s job (in my case) is to talk to Amazon’s Alexa and send off MQTT commands to control things.  In reality I’ve always had it return commands to Node-Red – because many of my controlled items are on timers and I need the two put together.

Continue reading Node-Red and Alexa with Big Timer


Sunday Alexa Post

WELL! You learn something new every day. Just had a call from a pal of mine (we both have multiple Amazon Alexa units around the house). Not only can you now call the thing “computer” – but one can now call the other…   so “Alexa, call house” rings the house Alexa from my office and makes an Intercom call – love it.

I really do wish they’d offer way more flexibility with keyword naming however. It is pretty much impossible to hold a Skype conversation about the subject without using the word “Alexa” at which point the units on either side of the call start apologising. I can’t imagine “computer” is the best idea either…

Imagine the conversation…. “Yup, I was just upgrading the computer the other day”. “I’m sorry, I didn’t understand…”

A key word like abracadabra might be nice – something you don’t use umpteen times a day.


RPI Prototyping

Prototype boardRemember a few blogs back where we were talking about prototyping boards for Raspberry Pi and similar and I showed a sample board and someone came back and said “Ah but you can get cheaper on AliExpress” – well, I bought one…

Here’s the link - £1.09 in sterling, free postage…. and I have to say… pretty good. Took a few minutes to solder the gold plated connector – holes are PTH and look ok.

So – if you click on the image you might get a larger version… the board came with the connector and nuts and bolts which I managed to lose within minutes of bringing the board into my office.  So you get a 5v rail and ground rail on the left. Over on the right there are full length 3v3 and ground rails and a whole line of holes for every pin (other than ground and power as you already have them).  The rest are all uncommitted runs.  

I have to say, for that price if you’re into tinkering – it’s a winner.  Should work with any of the Pi-type boards with the same connector – though clearly some of the IO pins will be wrong on some boards.  Very nice – just ordered another one.


Graphing System Info in Node Red and Grafana

We were just talking about getting system info into graphs in the comments in a previous blog entry – and I realised I already had some code for getting that info in Python – and using a library that can provide a LOT more.

So – as it was there already  - I thought I’d put this quick entry together for anyone interested.

Continue reading Graphing System Info in Node Red and Grafana


A Weekend of Links

Good morning (11/11)!

Well, this weekend I got up early to see what was happening with the 11/11 sales. What’s that you say? Well, if we only knew about British sites like RS components one could be forgiven for thinking that today was just another ordinary day. Fortunately we know better!

So for starters there are sales at both AliExpress and Banggood.  Both have some bargains and YES I blew the wallet this morning, new displays, new phone, you name it – discounts vary but they are genuine. Do you know of any other sites offering 11/11 sales of any note today??

Meanwhile Antonio suggested I point Node-Red newbies to this set of YouTube videos on Node-Red Fundamentals – I’ll leave it to you to decide if they are any good and do let us know. Of course if you want to play with Node-Red without getting your hands dirty there is always the FRED site (which just happens to feature BIGTIMER (under advanced).


Waterproof Box

Itead weatherproof boxA quiet post day today, some exciting gadgets I’m expecting remain in the postal system… but this little box turned up unexpectedly from Itead… it’s a waterproof box no doubt intended for their Sonoff products – and it would do a good job as their smaller units will fit into it no problem – handy for an outside light and you still get to see the flashing communication light.

However, it immediately occurred to me that it would be good for various other projects – ESP8266 etc. where you need the whole thing outdoors and maybe have a display on-board. Indeed I have such a thing in Spain where I have a little LCD backlit display monitoring the solar installation. It’s in a wooden box and I’m just hoping the weather out there won’t get to it (not much I can do if it does).

So anyway, not too exciting but I thought you’d like a look – no it won’t fit a Raspberry Pi unfortunately – JUST – and there’s no way to shave anything off those pillars – but it would take one of the smaller SBCs or an ESP8266 + small PSU no problem.  Now, how practical it will be depends on postage from where you are.


Enter Monitorix

MonitorixI recently did a post asking for input about useful tools for the Raspberry Pi and other SBC boards and the first to some out of this is Monitorix.

This is just a short blog – I’ve not had enough time to ensure I understand the usefulness of this – but at least on the Pi3 (which is happily running on my desk from a hard disk!!)  and at least in the short time I’ve played with it – this looks like a useful tool. Reader @thebaldgeek pointed me to a system monitoring tool called Monitorix – sadly the first set of online instructions I read failed miserably – however after a short exchange of messages we got it running.

Continue reading Enter Monitorix