There is an awful lot of people doing hobby projects with the ESP8266. I did not want to come up with the 47th incarnation of something, so the question came up, what an interesting project could look like. In the end I decided to develop a solution for managing a multitude of ESP8266-based devices. From a high-level perspective this will include the following components:
- CMDB: holds information about all devices
- Bootstrapper: prepares the raw module for all further work
- Security Manager
- Lifecycle Manager: Reference processes “from cradle to grave”
In my professional life I have been doing a lot of work on SDLC (Software Development Lifecycle) and configuration management, so the above project choice seemed a natural fit. It also happens that I am deeply interested in both topics and strongly think that poor application of them is often responsible for IT project failures.
The two main approaches for connecting an Arduino to an Ethernet network are the “normal” Ethernet shield or a module based on the ENC28J60 chip. While the Ethernet shield is easier to start with, it is comparatively expensive and also of little use for the smaller Arduino models (e.g. Arduino Nano or Pro Mini).
In contrast the ENC28J60 modules are cheap, small, and universally connectable. This comes, however, with the small downside that they are not supported by the Arduino IDE out-of-the-box. Of course, there is a myriad of web pages out there that deal with it in one aspect or another. There are two reasons why I add yet another:
- My ENC28J60 module (bought from AliExpress) is slightly different from the one usually seen. It does not need 3.3 volts but 5 volts, so the product description is wrong in that respect. Also, unlike all the other modules I have seen, it does not come with 10 but 12 connections.
- The usual recommendation for the library is EtherCard, but this did not work for me.
What finally worked for me was using the UIPEthernet library, which can also replace the standard Arduino Ethernet library. I connected the ENC28J60 module with a recently purchased Arduino Nano v3 clone using the following connections
|| (Pin 10)
|| (Pin 11)
|| (Pin 12)
|| (Pin 13)
The Arduino Nano pin layout can be found here
. The ENC28J60 module module offers a few more connections, as can be seen on the photo below. However, I used only the “usual suspects”.
The next step is to put this thing to use. I am currently planning some kind of data logger for 433 MHz signals, that are typically used for entry-level remote control purposes.
After many, many years I rediscovered electronics as a hobby in 2015 and started playing around with sensors connected to an Arduino Uno R3 and Raspberry Pi. It was fun to link them with motion detection sensors and switch lamps on and off. One drawback, however, was the pricing of those components, if you want to have quite a few of them connected by WiFi.
This was when I stumbled over the ESP8266 microcontroller. It is very small, really cheap (around 2 Euros if you order in China) and has WiFi built in already. The downside, compared to an Arduino, is that you need to take care of a lot of things on your own:
- Everything runs on 3.3 volts and 5 volts will kill the thing
- You need to get a USB-to-serial converter with 3.3 volt signal level
- Flashing is less convenient, since you need to change jumpers between normal and upload mode
But there is a really vibrant community out there and many problems have already been solved. So I will start writing about various aspects of this and look forward to feedback.