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Category: Technoblog

Mosquitto Unikernel using OSv and Capstan

Some time ago, I wrote a blog post about Unikernels and was quite enthousiast about the combination of OSv and XenServer. I had Cassandra running in an OSv container in a Jiffy and think Unikernels on hypervisors are quite better to manage and maintain than Docker images. If you want to know more about why I think they could be considered the successor of Docker, please do feel free to read my blog “Minimalist Cassandra VM using an OSv Unikernel“. In this blog I have written about my journey to get a unikernel Cassandra running, but I’m also trying to…

Arduino programming on the ESP8266

The ESP8266 has been gaining quite some popularity in the Internet of Things space. It is affordable and tiny and has multiple programming options. You can use Lua or C code to program the chip and it can virtually do anything you can also do with an Arduino. Some folks in the ESP8266 community have been debating about how great it would be if there were a third programming options. The ESP8266 should be made compatible with Arduino code! Richard Sloan and Ivan Grokhotkov eventually stepped to the plate and did the work to add the ESP8266 as a board to the Arduino…

New version of the NodeMCU board

I never really liked the NodeMCU, because the board was too fat. If you stick it into a breadboard, you’ll basically cover the entire breadboard and you’ll not be able to wire it up anymore. However, there’s a new version available now, which is an absolute blessing. On a breadboard, it still leaves a row on both sides uncovered, so that you can very easily wire it up to sensors and actuators. If you stop taking the drug suddenly or don’t take it at all: Your infection will likely not go away. It may be necessary to take additional calcium…

Connecting an ESP8266 to the SAP HANA Cloud Platform

As a proof of concept, I have tried to make a very easy setup of an ESP8266 and flashed it with simple firmware that connects to WiFi and sends temperature sensor data to the new SAP HANA Cloud IoT services. The aim is to have the chip to work in an autonomous mode, meaning that there will be no brokers or bridge involved that are taking messages from the ESP8266 to send it to the SAP HANA Cloud Platform. Calcium and phosphate solubilities were also influenced by temperature and the time after solution preparation. Under the Controlled Substances Act (CSA), CBD…

SAP HANA Café S02E04 – Internet of Things

On May 29, SAP and The Next View organised a CodeJam on one of my favorite topics: The Internet of Things. SAP has brought the Node.js-based Tessel development boards to experiment with. Of course, the emphasis shouldn’t be on the hardware and soldering, but on connecting them to the SAP Hana Cloud. I must say, this Tessel is quite a nifty little board that’s extremely easy to program. On the other hand, I also felt powerless when it decided to reboot out of nothing, perhaps due to some very hot-off-the-press firmware? Thing is that it did play nice with the HANA Cloud…

ESP8266 programming from Eclipse

As most people developing SAP solutions are currently using Eclipse for their edge projects, I thought it would be convenient to write a blog on how to connect your Eclipse environment to the ESP8266. Step 0: Get some ESP8266 chips and connect one to your computer The ESP8266 chips can be bought from various sources. Great resources to get the chip are Ebay, AliExpress or Banggood. You can buy the bare ones, but you can also buy a development board along with it. I’d highly recommend to buy a development board, because it makes life a lot easier. Most development…

VNSG CDV meetup & Internet of Things

On June 3rd, I had the privilege to address the custom development special interest group of VNSG about the Internet of Things and what SAP’s portfolio looks like in this space. Of course it was all about connecting Things to SAP’s HANA systems, either on- or off-premise. More important was even on how data collected through things are used to add value to the business, not only by just providing a dashboard, but by supporting or even making decisions by combining sensor data with predictive analysis and machine learning tools. Ultimately, businesses would have to completely reimagine and transform themselves…

Linking the ESP8266 to a Raspberry Pi through MQTT

In my previous blog post I have tried to explain why MQTT is the right protocol for IoT scenario’s. So it would be nice if the ESP8266 would be able to leverage this protocol as well. And it does! Over on the ESP forum, Tuan PM has been working on code to allow us to use the ESP boards as an MQTT client. The forum post is here and the wiki here. To get the ESP8266 to talk to the Raspberry Pi, I flashed Tuan PM’s MQTT examples with a few changes into the ESP and installed Mosquitto on my…

Minimalist Cassandra VM using an OSv Unikernel

When I was living in Singapore I “accidentally” got involved in maintaining a community site for expats in Singapore. Till now, one in a while I’m still doing a bit of webmastering on the site as one of my side activities/hobbies. Use case As part of the activities on that site, there is a regular newsletter to all community members. Since the site was launched, approximately 350k members have signed up, but many of them have moved on to another country or changed their email address. At the same time, despite various anti-spam mechanisms the member-database is also getting polluted…

Why you should use MQTT in IoT projects and why SAP should support it

While designing an IoT device, there are multiple options to connect them. Once of the considerations should be the protocol being used to chat to other devices or to a server. Previously, I would have easily chosen to make the interface REST based and have done so with Jeenode project a few years ago. But REST is not ideal as it is designed around a simple request/response model. So you ask “did my account balance change” and the response is returned “no it did not”. So you check again a few minutes later, and get the same response. Sound like…