TUXCON FOSS and OSHW conference 2018 in Plovdiv is just 18 days away, so plan your visit properly ;)

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TuxCon 2018 conference about Free Open Source Software and Open Source Hardware will be June 9 and 10th in Plovdiv.

This is community driven event done by volunteers with the support of local IT companies and it’s totally free to participate.

In Saturday 9th of June in the Technical University building there will be two rooms, for lectures and workshops.

Hacking Risc-V core, implemented on iCE40 FPGA and playing with it’s instruction set and making small “monitor” program which allow you to enter programs written on machine code and executed on iCE40HX8K-EVB + iCE40-IO will be demonstrated, so if you want to touch and make your first program on RISC-V “computer” with VGA monitor and keyboard you may find Rangel Ivanov lecture interesting.

Plamen Vaisolov is retro computer maniac and keep working on them, implementing modern floppy disk emulators and other peripherials. He will share his experience with all these who miss Karateka and Load Runner 🙂

Neven Boyanov will talk about his experience with LoRA network and how to start on low budged.

Dimitar Gamishev has two interesting talks, one is for the Open Source Hardware and Software GPS car navigation he made. In the  second he will speak about the home assistants like Google Home and Alexa, how to implement them with small Linux computer like OLinuXino and even with ESP32-Lyra and how to impress your girlfriend by switching on and off appliances and lights with your voice.

There will be KiCAD workshop where everyone (even with no knowledge) will learn how to install, configure and make small robot PCB with KiCAD. Then some general knowledges about PCB materials and how to prepare all files and send to PCB board house for manufacturing. How to select the components, footprints, good routing practices, DRC/ERC checks, Gerber generation and tips how to design your PCBs in way to be produced at lower cost. At the workshop will be our design engineers and you can talk to them directly about issues you encountered when worked with KiCAD or other CAD product.

 

In Sunday 10th of June we will have traditional Soldering workshop at Olimex training building, where we will assembly and program with Arduino small robot which can follow line or escape from labyrinth. This will be the same robot which PCB we will design in the KiCAD workshop in the previous day. We will go detailed through the program and study how modifications affect it.

The workshop with end with barbeque in Olimex backyard 🙂

 

We are looking forward to see you in Plovdiv soon!

MOD-BME280 precise Humidity, Temperature and Pressure sensor Open Source Hardware module with UEXT and Breadboard connector

MOD-BME-u

BME280 is digital humidity, temperature and pressure sensor with I2C and SPI interface.

You can see on this link comparison of different Humidity sensors

The operating conditions are:

  • Temperature -40..+85C;
  • Humidity 0…100 % Rh;
  • Pressure 300…1100 hPa  (+9000m..-500m above sea level);

The sensor works on 3.3V and is with very low power consumption 0,1..3,6 uA.

The easiest way to connect MOD-BME280 is with UEXT connector to any board with UEXT connector as shown on the picture above.

For boards which has no UEXT connector MOD-BME280 can be connected via four jumper wires on breadboard:

MOD-BME280-b

The KiCad files are uploaded on GitHub.

The demo software use Adafruit BME280 libraries with two small modifications. The default address in MOD-BME280 is 0x76 while Adafruit library is set to 0x77.

UEXT connector requires D8 to be set LOW to power and 10 ms delay to settle the power before addressing the sensor. The code is at GitHub.

When you run it you will see this:

Screenshot from 2018-03-27 14-35-38

The sensor is very precise, if you move board up and down you can see altitude changes. The 171 meter is the altitude of Olimex building.

MOD-BME280 is perfect for IoT application for environmental conditions logging due to the low power consumption and precise measurements. It can be used both for indoor and outdoor applications.

Is it hot or not? Contactless preciese Infra Red temperature measurement with Open Source Hardware MOD-IR-TEMP

MOD-IR-TEMP-bb

MOD-IR-TEMP is UEXT module which could be easily connected to all our boards with UEXT connector. It has MLX90614 contactless Infra red thermometer which allow you to measure objects temperature from distance.

MLX90614 has internal temperature sensor which can sense temperature in range -40+125C and Infra red camera which can sense external objects temperature in range -70+380C with resolution 0.02C and is calibrated with precision 0.5C in range 0-50C.

There are two ways to connectMOD-IR-TEMP to other boards – first is to use UEXT connector:

MOD-IR-TEMP-w

MLX90614 works on +3.3V so it’s important if you use Arduino board to make sure it operates at 3.3V or you will damage the sensor.

OLIMEXINO-32U4 has jumper which selects on what voltage it operates 5 or 3.3V you must put the jumper in 3.3V.

The sensor is read via I2C, Adafruit has library included in Arduino library manager.

UEXT onOLIMEXINO-32U4 has power enable and to operate D8 pin should be placed in LOW state.

Here is code:

#include <Wire.h>
#include "Adafruit_MLX90614.h"

Adafruit_MLX90614 modIrTemp = Adafruit_MLX90614();

void setup() {
 pinMode(8,OUTPUT);   //the following two lines enable power supply 3.3V on UEXT connector
 digitalWrite(8,LOW); //you do not need them if you use wire jumpers
 modIrTemp.begin(); 
 Serial.begin(115200);
}

void loop() {

Serial.print("Ambient = "); Serial.print(modIrTemp.readAmbientTempC()); 
 Serial.print("*C\tObject = "); Serial.println(modIrTemp.readObjectTempC());

 delay(1000); // can adjust this for faster/slower updates
}

If you use breadboard you should connect MOD-IR-TEMP GND, 3.3V and SDA to D2, SCL to D3. In this case you do not need to set D8 LOW to operate.

MOD-IR-TEMP allow precise temperature measurement from distance, we are doing some experiments to measure PCB reflow temperature from distance and to measure body temperature.

Our experiments show that how good the temperature is measured depend on object surface. Dark objects temperature is measured better than shiny objects.

If you place your hand in the front of the sensor the temperature is measured correctly from distance 0 to about 5 cm, then the measurement start to register lower temperature. Our guess is that the build in optics has limitation, if you want to measure temperature from greater distance you should add proper optics.

 

This is FOSDEM 2018

fosdem1

Last weekend in ULB (University Libre of Bruxelles) took place the biggest Open Source event in Europe – FOSDEM.

With 678 talks, split in 55 devrooms this is something every open source enthusiast waits whole year.

It’s amazing how the organizers make such event possible, between 8 and 10 000 people all around the world come together at one place. If you want to meet some open source project, Linux kernel or Linux distribution maintainer there is great chance to meet him/her there.

FOSDEM usually is made in the weekend Saturday and Sunday, but traditionally starts with Friday evening welcome beer party at Delirium cafe. Do not be fooled by the name nobody go there to drink coffee.

fosdem-delirium

Delirium usually can’t hold all people so the streets around it looks like this:

street

Every year this event become bigger and bigger. I was always wondering how they manage to keep their WiFi infrastructure in order with so many people attending. This year for the very first time the WiFi was impossible to connect to, so I guess we reach the infrastructure capacity 🙂

In Saturday the talks started, needless to say for me most interesting was the CAD and Open Hardware devroom.

One of the most anticipated talk there was about KiCad 5 new features.

Wayne Stambaugh the project manager started his talk with red T-shirt from Digikey and announced that Digikey made the single most significant donation to KiCad team just few days before the conference. So he said them “thank you” by presenting his talk wearing their red T-shirt.

wayne

It was very interesting to hear that Wayne got feedback from popular PCB prototype providers, that about half of PCB projects now they receive for prototyping production are made with KiCad! It’s amazing to see the progress KiCad made for the last 4 years!

I personally like more the T-shirt Wayne was wearing when he closed his talk 😉 KiCad team really like the complex boards we design with their product and this was very kind gesture.

wayne2

Another interesting talk was Introduction to LibrePCB . This is the first time I hear about this project and it looks itneresting. The author is obviously capable young man and thinkered a lot about how to make component libraries more easy to use, but while I was watching the talk I was wondering (as many others) why the author just do not join KiCad, which is already well established project and leading as features and completeness. We all know that KiCad team is very small and more people joining the project will make much more sense than to re-inventing the hot water, because you do not like some feature in this popular project. Well this is the open source 🙂 and everyone is free to scratch his own itch, but I would love to see Urban Bruhin helping KiCad to become better instead to duplicate the work creating similar product alone.

Jesús Arroyo Torrens presented Icestudio – graphical way to program FPGAs. I would say this is quite entertaining and easy start for beginners with no previous knowledge about electronics.

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Juan Gonzalez-Gomez (Obijuan) upgraded this talk with very entertaining presentation about what he did with Icestudio and small funny blocks he created. He is using his daughter as beta tester. I recommend you to watch this talk when the video is available.

Juan and Jesus are part of Spanish community working with FPGAs. You can see more about what they do on this site FPGAwars.

Staf Verhaegen shared his findings about is it possible today to implement ASIC design with open source tools. Very interesting topic, let’s hope the time Makers and small companies will be able to make their own chips with Open source tools is approaching.

My talk was about current TERES laptop status and the experience we got during the development with KiCad. Using FOSS tool like KiCad is great to make OSHW, but if you want to use latest features and the daily builds, they are available only via ppa repository for Ubuntu. This means if you use other distribution you have to build from sources every day. Windows daily builds are not available at all. This confuses many beginners who can’t manage to open our files when they want to study them as they use old builds (official Ubintu repository KiCad version is probably one year old, same for Windows version). My slides are now uploaded at Slideshare.

Other devroom talks I found interesting:

Exploiting modern microarchitectures Meltdown, Spectre, and other hardware attacks 

Programming UEFI for dummies 

Improving Linux Laptop Battery Life

Kodi and Embedded Linux

Linux as an SPI Slave

How to keep your embedded Linux up and running

Drive your NAND within Linux

Image capture on embedded linux systems 

New GPIO interface for linux user space 

It was nice to see three four other talks at FOSDEM by Bulgarian speakers!

Automating Your Lights with Open Source 
Turning On the Lights with Home Assistant and MQTT
Testing Red Hat Enterprise Linux the Microsoft way 

Current meta of video compression and probable futures

Overall FOSDEM is must see event for anyone who is interested in FOSS/OSHW.

Bruxelles is excellent location and offers lot to see, both Wizzair and Ryanair offer low cost flights to this destination and I don’t know where else you can drink beer from half meter glass (not half litter but half meter!) so looking forward to see you next year there!

half-meter

 

FOSDEM 2018 the biggest European even for Open Source technologies is approaching!

Screenshot from 2018-01-23 11-08-37

If you have not been to FOSDEM yet you don’t know what are you missing 🙂

Thousands of people who support Open Source meet together for weekend in Universite Libre de Bruxelles, share ideas and talk on interesting topics for the community.

Here is the list of all dev rooms which will be available. Needless to say for us most interesting is the CAD and Open Hardware dev room.

Looking forward to see you there!

TERES I DIY Open Source Hardware Modular Hacker’s Laptop update

teres

TERES-I DIY laptop first shipments started in September last year and we quickly sold the first initial production run. Immediately we start to get valuable feed back. Meantime the spare parts now are online and can be ordered.

FEEDBACK

Some of the feed back was quite pleasant like this one sent from Martin Krastev:

Здравейте,

Този път ви пиша не с въпроси по подръжката, а като потребител на Терес с
няколкоседмичен опит и впечатления ; )

Знам, че по идея Терес-А64 е бил замислен като хакерски ноутбук, но вече
седмици го ползвам като машина за разработка:
1. Освен проектите, по които работя, Терес сам си компилира и
компилаторите, които ползвам — 2-та ГБ памет наистина правят паралелното
компилиране възможно, та дори да е само -j2 или 3 (нещата, които компилирам са сравнително тежки, и по-голяма паралелност вече опира до суоп файла).
Така че голямо благодаря за ъпгрейда на паметта!
2. Въпреки нищожното охлаждане на чипа, Терес успва да държи по-голяма част от времето 1152МХц, което беше много приятна изненада за мен.
3. Клавиатурата се оказа доста ергономична, въпреки че в началото имах
опасения, че ще е малка.
4. Избора на чип от програмна гледна точка също се оказа удачен – някои
прозиводители на А53-базирани чипове орязват архитектурни фийчъри (демек – инструкции), но allwinner не са от тях (за изненада! ; ) Това ми позволява да не се тервожа, че код писан за по-глеми армове може да не тръгне на Терес.
5. Батерията носи добре на натоварване – дълги компилации не угасват по
средата! : ) А и шината за sd карти държи прилична скорост – напъно
сравнима с вътрешния флаш (при прилична карта, разбира се), така че и
проблемът с допълнително дисково пространство за големи проекти е решен.

Ами това е засега! Исках само да ви кажа, че с Терес сте в правилната
посока, тъй както сте създали напълно ползваем работен ноутбук за арм
програмисти, което си е постижение!

Поздрави,
Мартин

Google translate does satisfactory translation so I would not challenge my English translation skills 🙂

ISSUES

There were two issues we couldn’t catch during our tests and went with the first lot to our very impatient customers:

1. LCD backlight, some LCDs cause the backlight circuit inductor L11 to resonance at annoying audible high pitch harmonic frequency caused by the 300Hz PWM.

zoomIMG_20171219_083219

According to best Murphy’s law practices this problem didn’t show at the first few laptops we build and tested, but when we shipped the first lot some people complained back about it, so we had to find quick solution.
1.1. adding bigger capacitor 100 uF in parallel to C204 was solving completely the issue, but the boards were already produced and shipped to customers;
1.2. adding double adhesive tape which to press the L11 to the plastic cover solved the issue in most of the cases, if this was not enough sealing the L11 with superglue also stopped the noise, which was caused by L11 vibrations, needless to say this was quick dirty and messy fix

Инфорамция как да ъпгрейднем фърмуер на touchpad и бутони:

This issue was completely fixed with adding 100uF to second production lot

2. Touch panel buttons issue. We run out of GPIOs on the keyboard board so ADC was used to scan these two buttons. Again everything was OK when we tested the few laptops we assembled in house, but soon after the shipment people start complaining that sometimes they press left button but laptop register right button and etc, quite annoying!
2.1. the problem was partially fixed with changing the firmware, we posted new keyboard PCB firmware and instructions on GitHub but this not always solved the problem
2.2. the good fix solution was to decrease the resistor values on the PCB and use 1% precision resistors instead of 5% used initially

We do apologize to all customers who had experienced such problem, we guess they are not many, but if someone has still such issue after the firmware upgrade we will send free PCB3 replacement, just please send us your requests to support@olimex.com.

In the current KITS this issue is solved.

SOFTWARE

The initial version of the Linux software was not in best shape, the community helped us a lot and we are now on the third release. Special thanks to Alexey Korepanov for reporting lot of issues and fixes! He also made his own Gentoo distribution for TERES-I at GitHub!

PLASTICS

As you all know we suck at mechanical engineering and we had to find all plastic parts from Chinese laptop supplier. Some people asked about possible 3D designs of the laptop case but we are not capable to do this. So one of our customers Jeff Moe who obviously has mechanical engineering skills decided to re-design the plastics and make them as models in 3D printed format – he sends me pictures of his progress from time to time which I post here. So 3D makers be patient – there will be soon 3D printed designs and replacement parts for TERES!

EDIT: Jeff just noted me that the design is made by Brent MacKenzie from the Colorado Printing Project.

IMG_20180117_222635

IMG_20180118_101726IMG_20180118_182121

IMG_20180118_182208 (1)IMG_20180118_183356

It looks the LCD back plastic he designed is even easier to assembly than the original one.

IMG_20180118_190156

 

WHAT’s NEXT

I will post more in my next post about our progress in turning TERES-I DIY Laptop in portable lab with additonal FPGA board which makes from TERES component tester, Logic Analyzer and Digital Storage Oscilloscope with Sigrok.

TERES-I update. First feedback from our customers

magnet

Today we shipped all pending orders for TERES-I and we start to get valuable feedback from our customers!

First thing – we missed the magnet assembly in the instruction manual (blush). This leaded to laptops not go in suspend mode when lit is closed.

We updated this in the assembly manual 1.1 which is now on the web and included in the GitHub too in sources so people who notice typos and want to help improveing the Bulgarian-English language in which the manual is written.

Another issue reported immediately which we missed during our testing is that on small percentage of the laptops the LCD backlight step-up inductor cause annoying sound when LCD backlight is with 50% brightness.

BUZ

It’s a interesting phenomenia as the backlight PWM is 300Hz which is not possible to hear, but when LCD backlight is switch ON and OFF high current surges are happening and some harmonics cause mechanical resonance with this inductor.

The solutions may be few:

  • play with PWM frequency to get away from this frequency which cause the mechanical resonance – pure software approach which need lot of experimenting
  • adding small double adhesive matt on top of the inductor which make contact with the back plastic and this way absorb all vibrations – we start to add this mat as soon as we discover this issue to all laptops no matter if they buzz or not. Not very aestetish but quick and dirty solution:

ABS.jpg

  • Add more capacitors to the PWM power supply which to handle this current surge, adding 100 uF seems to remove the problem, but the first lot was already assembled and many laptops are already shipped – so this we will implement in the second assembly.

 

We have two reports about problems caused by the touch pad after “apt-get update / upgrade” we have to look more closely into this issue. For the moment we do not recommend you to update and upgrade your Ubuntu packages or if you do this and something stop working to revert to the original image – this is pretty easy just download the image write it to SD card, boot and run the eMMC copy script.

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