Widget of the Week #2: NodeMCU

NodeMCU module
NodeMCU module

I bet everyone who knows me was wondering how long it would take before I posted this one?

The basic ESP8266 modules such as the ESP-01, -07 and -12 are small and cheap but not hacker-friendly so there are various modules around that put an ESP module onto a breakout board and provide essential functions such as voltage regulation, USB-serial and level conversion.  The forerunner is the NodeMCU which was originally intended as a Lua/NodeMCU firmware development platform but is perfectly good for other environments.

The heart of it as you can see in the picture, is an ESP-12E module that occupies about a quarter of the board and provides nine digital I/O lines with varying capabilities, and an analogue input that can also monitor the supply voltage, useful for battery powered applications.  The board itself has two strips of pins that you can connect to directly or plug into prototype board.  It fits neatly onto the little 170-pin boards with one row of holes exposed either side to make connections to and this way it’s kept safe from shorting to any metal objects on your workbench.  On the larger 400-pin boards you’re left with plenty of space to add components.

Usefully it has two small pushbuttons for Reset and Flash though as I recently discovered (the hard way, but that’s another story), the latest ESP8266 board support package for the Arduino IDE automatically puts it into flash mode.  It uses the increasingly popular (since FTDI-gate) Silicon Labs CP210x USB/Serial interface for which you’ll need to install the driver but has proven flawless.  The I/O lines are still 3.3V but most peripheral devices are happy with that if you give them a 3.3V supply – NeoPixel RGB LED strips for instance.

Intended as a lightweight development board, if you’re targeting an embedded application it’s ideal because you can switch to using the ESP-12E alone once you no longer need the serial interface and power regulation.  For educational use it’s just plug and play with enough I/O for many experiments and demonstrations.  I’m gradually working through my boxes of sensors and displays testing the libraries with a view to documenting this in the wiki.  At the present time it’s my recommended starter device and currently available via AliExpress for as little as £3.60 you can’t go wrong.

2 Comments

  1. Great blog, thanks for posting.

    I’m not so familiar with ordering items on aliexpress or banggood. Banggood is tempting as some suppliers ship from the uk. Would I get better value from aliexpress though? Also, are there any caveats such as unreliable suppliers on either site?

    Separately, what’s a good size breadboard for experimenting with esp8266 projects?

    Many thanks, looking forward to more posts and projects.

  2. Good question – we’ll do a post on it in the near future, but think of Banggood as China’s Amazon versus AliExpress as China’s Ebay or Amazon Marketplace.

    With Banggood you’re buying from Banggood themselves – and they now have regional distribution for popular items which gives much faster delivery (they ship from just up the road in Greenford) but at a higher price though if your order is over the customs threshold it may not make a lot of difference.

    AliExpress on the other hand is the ‘retail’ outlet of Alibaba, a massive Chinese distribution network. Many of the retailers there are simply affiliates or white-box sellers, so for instance, I’ve ordered one NodeMCU from two suppliers (because more would have incurred silly postage charges) and they turned up in the same delivery in identical packaging with identical labels. Buy from a seller that has (a) a good rating over lots of sales (>1,000 or 10,000 ideally) and also has fulfilled many orders (>10) for what you’re buying.

    Whereas with Banggood you deal with them direct in the case of a dispute, with AliExpress it’s rather like Ebay – only more so – your money is in escrow until either you release it, you open a dispute or the protection time expires. If you place more than a couple of orders at a time you might find it worth running a spreadsheet to keep track.

    Delivery times from both are typically two weeks though you can get stuff in as little as a week or as much as a month.

    There are others such as DX and DHgate but I don’t have much experience.

    I’ll discuss with Nigle who shares my serious Ali/Bang habit and we’ll write a wiki on the subject very soon.

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