It’s Friday again and time for our Guess What is this Quiz

Screenshot from 2019-04-19 17-39-37

We just finished the routing of this new board, so the question is Guess what is it?

Screenshot from 2019-04-19 17-39-51.png

It uses Quectel EG21-G module which works anywhere in the world covering all GSM standards and frequencies. It also has GNSS build-in.

Screenshot from 2019-04-19 17-40-08

It also can connect to any network 2G-3G-4G whichever is available (sorry no 5G yet 😉 ).

Once the prototypes are ready and check we are preparing Crowd Supply campaign for it! Hint Fits perfect to LoRa-GATEWAY and allow connection where no wires and optics like mountain hubs, remote areas etc.

You can post here or retweet/share/boost on Twitter/Facebook/Mastodon/Diaspora and in Monday we will let to decide who will win one of our new eduArdu educational board.

Have a nice weekend!

UODATE 22-04-2019: selected @netsigi as winner!


Open Source Hardware ESP32-POE-ISO is now in stock and we are very proud with the result


We are very proud of our new ESP32-POE-ISO and delighted to announce it’s already in stock ready for order!

What we did with this improved version of the low cost ESP32-POE power over ethernet solution for IoT?

  1. As many requested we add 3000VDC galvanic insulation. Now you can program / debug while connected to PoE switch or router;
  2. Many asked for more GPIOs so we set SD-card in 1 bit mode and this way released 3 GPIO pins for other use;
  3. We got hints that new Espressif SDK allow ultra deep sleep modes for ESP32 and we re-designed the power supply part that now the ESP32-POE-ISO has consumption down to 200 uA (130uA of which are taken from ESP32-WROOM-32D module). The rest board without the module consumes just 70uA;
  4. As per your request now battery level has option to be monitored with the ESP32 ADC;
  5. There is External power detection option, so your software will be aware when run sole on battery and when have plenty of power.
  6. The Isolated DCDC we use is 2W and provides 400mA @5V, 100mA are reserved for the battery charge (available if no battery is connected) and 100mA are provided for ESP32, which leaves up to 200mA @5V for your additional circuit.

We love to listen to our customers and we did our the best to complete most of the requests we got with this new version.

Open Source Hardware ESP32-POE board now has new version with 3000VDC galvanic insulation


ESP32-POE is one of our best selling boards, it’s low cost less than EUR 18 in single quantity and allow you to make IoT sensor network with existing Ethernet POE infrastructure.

The end node can provide up to 4W combined on +5V and +3.3V output to external components and circuits which is more than enough for most applications.

To simplify the design and lower the cost ESP32-POE has no galvanic insulation.

Some customers asked can we add such insulation – sure it’s possible, meet the new ESP32-POE-ISO. So here above on the picture you see first samples of the insulated POE board.

We wanted to keep is as similar to existing POE as possible, as you can see the new board is just 15 mm longer and keep same pinout on the connectors, allowing ESP32-POE to be directly replaced with ESP32-POE-ISO.

What are the benefits? Now you can safely debug your ESP32-POE-ISO while connected both to computer with USB cable and Ethernet POE cable.

For the insulation we use 2W DCDC converter with 3000VAC insulation. The available 400mA are split between ESP32 and external circuit and in most application will be sufficient.

The price of ESP32-POE-ISO is EUR 23.95 (only EUR 6 more than non-isolated ESP32-POE) in single quantity.

If 2W are not enough, we can produce same board with 3W DCDC which allow 600mA current, but the price will rise with another 3 EUR to EUR 26.95 in single quantity.

LoRa experiments in Plovdiv

Screenshot from 2019-02-20 12-24-46

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.



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


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


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


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


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



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.


Seven new version of ESP32 modules are add to our web shop


We add to our web shop seven new ESP32 modules:

ESP32-WROOM-32D-4MB – this is equal to used by us ESP32-WROOM-32, it uses D0WD instead of D0WDQ6 which is with smaller size and Espressif recommend it for new designs.

ESP32-WROOM-32D-16MB  has 16MB of Flash

ESP32-WROOM-32D-4MBHT is High temperature +105C module for demanding applications.

ESP32-WROOM-32U-4MB is with U.FL connector for external antenna

ESP32-WROOM-32U-16MB has 16MB of Flash

ESP32-WROOM-32U-4MBHT is High temperature +105C module for demanding applications.

ESP32-WROVER-4MB has 4MB Flash and 8MB of PSRAM.

The high temperature modules are still not in stock as Espressif manufacture these now, but all others are in stock.

NB-IoT seminar slides and BC66 datasheets are online


NB-IoT seminar by Quectel and Comet had more than 130 peoples interested. The hall was full even with people not having place to sit.

It’s understandable as NB-IoT is one of the fastest developing technology.

NB-IoT is new, the standard draft was made in July 2015 and at the beginning of 2016 already has been accepted, just in 6 months.


For comparison LoRa is technology from 2008, but just last couple of years people start using it widely. The other LPWAN Weightless was announced in 2012 but first ever devices were made in July 2017.

Why NB-IoT was developed so fast?

Because Qualcomm, Vodafone, Ericsson and Huawei which are major player in mobile networking are behind it. NB-IoT works with the existing cellular network base station hardware. In practice it’s lightweight LTE implementation and just uses narrow band communication. So to add support for NB-IoT only software upgrade is necessary and it uses the existing infrastructure.

Another boost for NB-IoT is that it was first choice for IoT implementation in China as product with Chinese company (Huawei) involved vs LoRa which is considered technology controlled by US company.


According to Quectel slides they sold in 2017 36 million modules for about 245 million USD i.e. average price per module is USD 7 which is already in LoRa pricing range.

NB-IoT though offers lot of advantages compared to LoRa. The Narrow Band communication allow the receiver sensitivity to increase many times and with one base station is possible (from the slides) to cover up to 100 km with NB-IoT. Also one single cell base station can serve up to 100 000 NB-IoT nodes!


Quectel flagman for NB-IoT is BC66


It’s Multiband: B1+B2+B3+B5+B8+B12+B13+B17+B18+B19+B20+B25+B26+B28+B66 i.e. covers completely all regions US, EU, Asia, Africa, Australia and once you do your design you can scale worldwide.

Anothe major advantage is that it works from 2,1 up to 3.6V. This is very important as Lithium batteries capacities usually are defined when battery is discharged from 3.0 to 2.0 V.

NB-IoT is different from 2G/3G where there are 2A pulses when link to base station is eastablished, here max current drawing is only 250mA when you establish link to base station. Once established link do not need to be re-connected when the module go to PowerSavingMode and wake ups!

Screenshot from 2018-12-07 12-19-10.png

This is why their recommended design has just 100uF filtering capacitor necessary!

Another nice surprise is that in BC66 you have Cortex-M4 78Mhz ARM processor with 400KB Flash and 400KB RAM running FreeRTOS, which you can use for your own applications. There is also ARDUINO support:

Screenshot from 2018-12-07 12-23-03.png

Overall BC66 seems very interesting and we are dedicated to release OSHW boards with it targeting same applications like with LoRa: Smart metering, Parking, Smart City, Industry 4.0 etc.

Who ever have dealt with Chinese vendors know how they hide all info from their potential customers, in this regard Quectel made difference by releasing all BC66 info online after the seminar. You can view all presentations and the datasheets here.


Previous Older Entries