Building a Slack button with ESP8266/Arduino

I have recently discovered the powerful ESP8266-based development boards. These boards have built-in WiFi connectivity and many GPIOs, low consumption and can be programmed in many different ways. In this article I will show how to build a smart button that sends a message to a Slack channel, using a Wemos D1 mini pro. This board can be programmed in many different ways. In this article, I will show how to do it using the Arduino-compatible programming interface. [Read More]


Last weekend I went to FOSDEM 2017. In this post, I will share links and notes regarding several talks I have attended to. Etiene Dalcol (@etiene_d) spoke about Making wearables with NodeMCU. Although I have very little knowledge of the Lua programming language I attended to this talk because I had heard about NodeMCU as a firmware to power the mighty ESP8266 dev kits. During the talk, Etiene discussed the different boards available in the market (I didn’t know about the ESP8285, a good alternative), how to upload the Lua code to them and several examples, including a party dress with LEDs attached that changed patterns controlled by her wristwatch (and even by the music volume itself). [Read More]

Codemotion 2016 highlights

This weekend I have attended to Codemotion 2016. I have gathered some links of talks and workshops that I consider really worthwile to review: Susana Morcuende (@yosoytumadre_ti), Yamila Moreno (@yamila_moreno) and Jorge Arévalo (@jorgeas80) talked about Los androides no sueñan con ovejas eléctricas; sueñan con conciliar. It is quite refreshing to find a talk about this important aspect of work. People attending to the talk seemed really interested on the subject and enjoying the talk. [Read More]

Chaos Monkey talk at OWASP Meetup

Yesterday I gave a brief introductory talk at the OWASP Madrid Meetup: “Haciendo el (Chaos) Monkey” (I gave it in Spanish). These are the links to the video and the slides. [Read More]

dotGo 2016

This week I have attended to the dotGo2016 conference in Paris. It is a one-day, one-track, 20-minutes-per-talk conference. Very few laptops, people were really focused attending to the dense talks. Here I will highlight some concepts that I have found interesting in some of the talks: Dave Cheney(@davecheney) talked about first class functions (Don’t fear the first class functions), how to implement them in Golang and why they are sometimes a good choice because of the advantages of passing behaviour (encoded in functions) over raw data structures. [Read More]

An intro to Hypothesis

I have recently listened to the Episode 67 of the TalkPython podcast, which is an interview with David MacIver, the primary author of the Hypothesis Python library. The concept of property based testing immediately caught my attention so I decided to give it try. The rough idea behind property based testing is focusing not on specific examples of inputs and otputs but checking the properties of the expected results. It has many concepts in common with functional programming. [Read More]

Caddy 0.9 has arrived

Yesterday, Matt Holt announced the 0.9 Release of Caddy server. It is not a normal release, there are very important changes in the project. Let’s see some of them. Caddy has been redesigned into a core + plugins architecture. Now, the server part is a plugin, so you can basically exchange HTTP for DNS, mail, SSH, Git… yes, it is amazing, that means TLS out-of-the-box for any supported protocol server. [Read More]

PyData 2016 Madrid

Recently I have attended to the PyData 2016 conference held in Madrid. It has been a two-days single-tracked conference covering aspects of Python and data science. I will try to share some links and comments of that have been more relevant to me. Christine Doig (@ch_doing) opened the conference with a keynote entitled The Hitchhiker’s Guide to Data Science. Christine works at Continuum, one of the companies leading the data science revolution in the Python ecosystem. [Read More]

Bringing SSL/TLS and HTTP/2 with Caddy

Some weeks ago, Fernando gave a very interesting talk about Caddy and HTTP/2 at the Madrid Golang users group meetup. It immediately caught my attention and decided to get hands on with it. Basically, Caddy is a web server that implements the HTTP/2 protocol for the modern web. This version provides many advantages over HTTP/1.1 as multiplexing and TLS by default. For me, the selling points of Caddy are two: [Read More]

FOSDEM 2016 Day Two

[]() On Sunday, I attended to some talks in the Configuration Management devroom. These are the notes and links from the talks. Arthur Lutz (@arthurlutz) talked about After describing your infrastructure as code, reuse that to monitor it. He presented an architecture in which he ran the Munin monitoring directly from Salt minions. It was interesting to see the variety of metrics they are currently watching. Marco Ceppi (@marcoceppi) gave a talk entitled Beyond config management: Tackling orchestration and modelling on top of config management. [Read More]