This blog has been moved to https://perezmeyer.com.ar/
Solo sé que sé querer, que tengo Dios y tengo fe.
(y eso no es poca cosa)
domingo, 30 de mayo de 2021
martes, 16 de marzo de 2021
On configuring RAK LoRa devices, or how to avoid their Windows-only serial application
tl;dr: use a serial terminal which can buffer input and send it all at once, lines should end with \CR\LF.
I'm am currently working on bringing up a LoRa network in Bahía Blanca. Parts of the nodes I need to set up are made by RAK Wireless.
According to their documentation the nodes can be configured by using a serial connection to them. So I quickly turned to minicom for it, with no avail. Somehow I could read whatever the device was writing to my machine but could not write any commands back to it.
In order to get the issue solved I switched to running their RAK serial port tool under wine. Making it work made me download and install a huge amount of Windows libraries and tools, but in the end I wanted a Linux-only solution.
After much digging the web, trial and error I've found a way to solve this:
- Commands should end with \CR\LF.
- The command needs to be sent quickly, all in one go, trough the serial port. This means it can't be typed and sent as normal serial consoles.
The solution for (1) in minicom is easy, but I don't know if minicom is capable of doing the buffering thing, so I went to use cutecom, for which one has to enter the input and send it all at once.
martes, 18 de agosto de 2020
Stepping down as Qt 6 maintainers
After quite some time maintaining Qt in Debian both Dmitry Shachnev and I decided to not maintain Qt 6 when it's published (expected in December 2020, see https://wiki.qt.io/Qt_6.0_Release). We will do our best to keep the Qt 5 codebase up and running.
We **love** Qt, but it's a huge codebase and requires time and build power, both things that we are currently lacking, so we decided it's time for us to step down and pass the torch. And a new major version seems the right point to do that.
We will be happy to review and/or sponsor other people's work or even occasionally do uploads, but we can't promise to do it regularly.
Some things we think potential Qt 6 maintainers should be familiar with are, of course, C++ packaging (specially symbols files) and CMake, as Qt 6 will be built with it.
We also encourage prospective maintainers to remove the source's -everywhere-src suffixes and just keep the base names as source package names: qtbase6, qtdeclarative6, etc.
It has been an interesting ride all these years, we really hope you enjoyed using Qt.
Thanks for everything,
Dmitry and Lisandro.
Note 20200818 12:12 ARST: I was asked if the move has anything to do with code quality or licensing. The answer is a huge no, Qt is a **great** project which we love. As stated before it's mostly about lack of free time to properly maintain it.
martes, 2 de junio de 2020
Simplified Monitoring of Patients in Situations of Mass Hospitalization (MoSimPa) - Fighting COVID-19
In the beginning
When the pandemic reached Argentina the government started a quarantine. We engineers (like engineers around the world) started to think on how to put our abilities in order to help with the situation. Some worked toward providing more protection elements to medical staff, some towards increasing the number of ventilation machines at disposal. Another group of people started thinking on another ways of helping. In Bahía Blanca arised the idea of monitoring some variables remotely and in masse.Simplified Monitoring of Patients in Situations of Mass Hospitalization (MoSimPa)
This is where the project Para Ayudar was created. The project aims to produce the aforementioned non-invasive device to be used in health institutions, hospitals, intra hospital transports and homes.
The importance of early pneumonia detection
A vast majority of Covid pneumonia patients I met had remarkably low oxygen saturations at triage — seemingly incompatible with life — but they were using their cellphones as we put them on monitors. Although breathing fast, they had relatively minimal apparent distress, despite dangerously low oxygen levels and terrible pneumonia on chest X-rays.
The project from a technical standpoint
General system description
The hardware
The software
MoSimPa's monitor main screen |
Plots of a patient's data |
Alarm thresholds setup |
ABM main screen |
ABM internments view |
Certifications
Funding
sábado, 7 de marzo de 2020
Qt 4 removed from Debian Sid (unstable)
Thanks should go to many people. You know who you are, and I really appreciate the support and time you put into this. **Thanks**
jueves, 9 de enero de 2020
Qt 4 removed from Debian bullseye (current testing)
viernes, 9 de agosto de 2019
Developing Nordics' nRF9160 DK using Qt Creator
This board actually has two interesting ICs: the nRF9160 which anyone would expect and a nRF52840. At first I'm targeting the first one.
The nRF9160's firmware is based on Zephyr which uses CMake. This is great as my preferred IDE is Qt Creator which has quite nice CMake integration.
Preparing the toolchain and proprietary code
There is of course some Nordic proprietary code to put in the mix. So the first step is to setup Nordic's SDK. For that one needs to follow the "Get started with development" section in their web page. One needs to download an nRFConnect AppImage binary and start it. How safe it is to run proprietary code in our machines? Now that's an interesting question.
Once there, and still following Nordic's documentation, we need to install the "Getting started Assistant" and run it. We will follow all steps in it except the last ones for installing a proprietary IDE. We want to code using Qt Creator after all.
Building the asset tracker example from the command line
So let's start by trying to build the example (the only one so far?) from the command line. After some trial and error I've got the following:
mkdir build
cd build
GNUARMEMB_TOOLCHAIN_PATH="/opt/gcc-arm-none-eabi-7-2018-q2-update" \
ZEPHYR_TOOLCHAIN_VARIANT=gnuarmemb ZEPHYR_BASE="$NCS_BASE/zephyr" \
cmake -DBOARD_ROOT="$NCS_BASE/zephyr/boards/arm/nrf9160_pca10090" \
-DBOARD="nrf9160_pca10090ns" ../
Where NCS_BASE is the path to the previously downloaded SDK. In this case I selected the non secure version build for this board.
The next step is then easy.
Building the asset tracker example from within Qt Creator
Once we've got to compile the example from the command line switching to Qt Creator is easy. First of all we want to set up a Kit as I did for the nRF51822. Follow the instructions there but this time set up the new GCC version required by this development kit.
The next step is to provide as much definitions as possible as part of the kit itself. Got to Tools → Options... and then to Kits. Select the newly created kit (I called it nRF9160) and then change "CMake Configuration" settings. The resulting text should look like: