Open Source Hardware boards for NB-IoT technology presented at RuseConf 2019

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RuseConf is part of IT-Tour. Every year IT-Tour organize conferences in Sofia, Plovdiv, Varna, Ruse, Burgas, Veliko Tarnovo. They are all made by volunteers and completely free to participate. The idea is to encourage local IT community to share ideas and interesting talks.

This weekend on 28th of September was RuseConf and Olimex presented there our newest NB-IoT boards.

NB-IoT-DevKit boards will be on our web for sale next week with sale price per one unit EUR 18.00. They employ the NB-IoT technology which uses existing LTE 4G network to implement LPWAN.

The NB-IoT devices use low power and can operate on battery for 10 years if network traffic is less 200 bytes per day (this may seems small but SigFox for instance allow 2 to 140 uploads of 12 bytes messages per day. NB-IoT has no restrictions and limits, but if have to be careful as more traffic means more battery discharge. One GSM LTE base cell can connect up to 100 000 NB-IoT devices at same time ( but of course it no one talk on his GSM phone in this cell range) which beats LoRa gateway maximal theoretical 49 connections. Also the NB-IoT module we use has +20dB more sensitivity so if normally one Base cell can connect to NB-IoT nodes up to 10km this module has 10 time more sensitivity and can connect up to 100 km from the base cell. This of course is marketing claim theoretical claim as explained in the talk but still impressive.

The slides are in Bulgarian and English and uploaded at Slideshare.com

 

LoRa experiments in Plovdiv

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We are working for some months on OSHW LoRa nodes and our goal is to bring up free to use for non for profit Smart City solutions LoRaWAN network which to cover city of Plovdiv .

Yesterday we installed our First LoRaWAN Gateway made with T2-OLinuXino-LIME2-e16GBs16MB + RK831 + +6dBi rod antenna on Rilon Building which is about in the city center and with height good for antenna installation.

You can see on above map – the “Raspberry Pi” is hardcoded in RK831 firmware but do not worry there is industrial grade Linux computer in the gateway.

 

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We start experimenting with our LoRa868 and MOD-LoRa868 modules and made portable GPS tracker device like this:

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The results are nice. We cover almost 2km circle around the antenna. With few spots which are shadowed by tall building.

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The secret in the big distance is the good gain gateway antenna!

We really are impatient to release these LoRa gadgets as soon as possible, but unfortunately it takes much more time than we expected.

There were lot of issues with the Semtech/ARMmbed reference designs like the RF part of their 868Mhz design actually has components values which make 915Mhz device and vice versa. We spent weeks to understand why the communication distance is not as good as expected, before we realize that we use 915Mhz LoRa nodes with 868Mhz antennas! Once we get everything complete and tested will put our boards on the web for sale and publish OSHW their correct schematics and component values, so other will not waste their time like we did.

One issue we encountered with RK831 Gateway is that it freeze from time to time when receive malformed packets and need to restart. As RK831 firmware is not open source we can’t debug the cause of this problem. The workaround now is when host lose connection with gateway just reboot latter. Really not most elegant solution, but so far we can’t do anything else.

We are preparing two more Gateways to install in the next days, which will cover more parts of the city.

 

 

FOSDEM slides and video

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FOSDEM is always impressive, even for people like me who go there for 7th time. It’s great place where you can see developers for almost every FOSS big project and talk face to face.

It’s really pleasure to see that last years there is Hardware related dev rooms too.

KiCad as always attracted lot of attention

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but CAD and OSHW devroom was pretty small, so people are waiting on long tails to get in and just few lucky ones succeed:

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For security reason the organizers didn’t allow people to stay standing or sitting on the floor, but this didn’t stop all. Next day I spoke to lot of friends and they said – I knew there will be no space for all who want to enter, so I just stay at the cafeteria and watched the stream.

It was same situation at the Andre Przywara talk One image to rule them all. There was no space in the room to accommodate all people who wanted to attend it.

There were three talks from Plovdiv at FOSDEM this year 🙂 Our friend Leon Anavi had two talks Making Open Source Hardware for Retrogaming on Raspberry Pi and The Software Developer’s Guide to Open Source Hardware. It’s cool as his full time job is as software engineer but as you can see he does OSHW in his free time and obviously like to talk more about his hobby than his daily work 🙂

I talked about some new OSHW boards we are working on last few months.

The idea is to build LoRaWAN infrastructire and install some free Smart City solutions in Plovdiv which to set example and to put all our work on GitHub so if other cities want to follow to be able to replicate and scale what we did and hopefully people to get aware more about the power of the open source hardware and software solutions.

Here are my slides and here is my attempt to speak English at FOSDEM. Sorry subtitles are not available 🙂

It was incredible pleasant surprise to see OLinuXino-LIME2 mentioned in Danny Haidar‘s lighting talk Creating a Computing Revolution: from Personal Computers to Personal Servers.

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NB-IoT event organized by Comet electronics on December 4th

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NB-IoT is one of the promising LPWAN technologies I review in both my Industry 4.0 and OpenFest 2018 talks.

It’s lightweight LTE technology which has only 48 bytes of payload and 30kbps up and down link. Some call it 0G.

NB-IoT is specified by 3GPP standartization organization, same which standartize 2G/3G/4G/5G. It works flawless with existing cellular technologies with simplified RF and processing.

With these high speeds and small payloads the average consumption of NB-IoT make it more efficient even than LoRa, but there is many things to consider in your design.

First is that NB-IoT never will reach LoRa price point, it will be always about x2 more expensive.

Second – some modules like for instance the popular Ublox SARA-N2  which cost EUR 11 for 250 pcs, can’t work at lower than 2.75V power supply. Most Lithium batteries capacity is quoted with battery discharge from 3V to 2V so these modules will work only with fraction of the capacity of Lithium batteries. They are designed to operate from 2.75 to 4.2V i.e. targeting LiPO re-chargeable batteries, but these will never stay charged for 10 years as NB-IoT technology promises, so this is really odd design choice by Ublox.

Another thing to take into consideration is the high current pulses which LTE technology introduce (up to 2A when link is established). So even on paper NB-IoT to looks better than LoRa it still could be implemented with compromises where these benefits to be not seen.

Fortunately some Chinese vendors (like Quectel) made their modules BC66 to work from 2.1V.

Comet Electronics is organizing on December 4th NB-IoT event together with the first cellular operator which implements NB-IoT connectivity in Bulgaria – A1 and with Chinese module supplier Quectel.

It would be interesting to touch and evaluate this technology which is relatively new, has no infrastructure and is dependent by subscription fees only.

NB-IoT Gateways are not expensive and cost about $2000, but you can’t use them unless you have licensee to operate at GSM frequency (and these licensees cost millions of EUROs at least here in Bulgaria) so you can use your gateway only in Faraday cage :). This is where LoRa technology shine and this is what makes it so popular! No subscription, no fees for data transport, everyone can run his own gateway.

This is also one of the reason NB-IoT infrastructure is not so well developed – the investment is small, but the mobile operators still can’t figure out how to squeeze money out of this. There are already several providers on the net which sell NB-IoT SIM cards with EU roaming and with low cost like $12 per year, but local operators will find a way to shut these down and take their share.

Electronica 2018 highlights – AI, Smart Solutions, Communication and Security

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Electronica in Munich trade fair is the most important meeting place for the electronics industry. Last week more than 3000 exhibitors and 80 000 visitors met together .

What was very visible this years is that beside the traditional big number of German companies the second biggest by number of companies exhibitor was China. There were both big:

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and small companies:

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Artificial intelligence, Machine Learning, Smart solutions, Connectivity and security were dominating topics among the exhibitors.

LoRa and NB-IoT solutions were present on almost every fifth booth 🙂

The slides from Industry 4.0 meeting in Stuttgart are online

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Open Source / Free Software for Effective Industry 4.0 Meetup  organized by Nexedi GmbH  and hosted by Fraunhofer IAO was held on 12th of November in Stuttgart.

There were quite interesting talks mostly focused on Open Source Technologies and their possible use in Industry 4.0.

My slides are now uploaded at Slideshare.

The biggest FOSS/OSHW event in Bulgaria – Open Fest is 3-4 of November

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Our favorite Open Source event – OpenFest is approaching. Every time I go there I do wonder how small Bulgaria attracts so many people there – thousands of people meet together. Probably the answer is that IT is developing very well and lot of people in Bulgaria work in IT industry.

I’m really pleased to announce that my proposal to talk about LoRa/TTN/LoRaWAN myths, possibilities, applications and limitations is approved! I will try to compare all popular LPWAN solutions, why LoRa is leading there (hint: open source 😉 ) and how you can calculate your power requirements, link budged etc to make sure your application will work with years on battery.