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by jeanleflambeur
Tue Aug 08, 2017 7:04 am
Forum: Beginners
Topic: What are the best languages and frameworks to make a raspberry touch screen program?
Replies: 4
Views: 1612

Re: What are the best languages and frameworks to make a raspberry touch screen program?

I've been using C++, Qt and QML for touchscreen and non-touchscreen for years. You write your program processing in C++ and then add some thin proxies that expose the necessary data to QML. The whole UI is written in QML (a javascript flavor). Here are some examples & tutorials: http://doc.qt.io/qt-...
by jeanleflambeur
Sat Jul 22, 2017 1:09 pm
Forum: Wanted
Topic: New 5.9" HDMI screen. Any interest?
Replies: 23
Views: 5016

Re: New 5.9" HDMI screen. Any interest?

I'm sure you know wifibroadcast for live FPV video using RPI? I do know of wifibroadcast. I have a very similar system included in my code base using 2 TPLink WN722 cards receivers for diversity. Manga screens are great indeed for ground stations with almost double the brightness of the official ra...
by jeanleflambeur
Sat Jul 22, 2017 9:24 am
Forum: Wanted
Topic: New 5.9" HDMI screen. Any interest?
Replies: 23
Views: 5016

Re: New 5.9" HDMI screen. Any interest?

Those are some great LCDs. I pledged for a 5.9" one to use in my quadcopter remote control. Seems to be bright and compact enough. Some inspiration for your build https://www.intel.de/content/dam/www/public/us/en/images/photography-consumer/16x9/drones/cockpit-ground-control-unit-16x9.jpg.rendition...
by jeanleflambeur
Fri Jul 21, 2017 5:38 pm
Forum: C/C++
Topic: RaspberryPi C++ Blog
Replies: 26
Views: 4724

Re: RaspberryPi C++ Blog

Using just Visual Studio and ignoring other build systems covers just a narrow portion of the needs of a hobby and professional programmer. One one hand you have programmers (both professional and hobbyists) that develop on linux and other OSes where VS doesn't exists. On the other hand you have lot...
by jeanleflambeur
Mon Jul 17, 2017 11:17 pm
Forum: Wanted
Topic: New 5.9" HDMI screen. Any interest?
Replies: 23
Views: 5016

Re: New 5.9" HDMI screen. Any interest?

Those are some great LCDs.
I pledged for a 5.9" one to use in my quadcopter remote control. Seems to be bright and compact enough.
by jeanleflambeur
Mon Jul 10, 2017 8:05 am
Forum: Automation, sensing and robotics
Topic: Best Hunidity and temperature sensor
Replies: 4
Views: 2462

Re: Best Hunidity and temperature sensor

I replaced all the DHT22 with SHT21 and couldn't be happier. The DHT22 has other issues - like its internal voltage regulator failing and heating up the chip and many communication failures. The SHT21 has better accuracy, it's i2c as opposed to the bitbanged protocol the DHT is using and is an overa...
by jeanleflambeur
Mon Jul 10, 2017 7:17 am
Forum: Wanted
Topic: New 5.9" HDMI screen. Any interest?
Replies: 23
Views: 5016

Re: New 5.9" HDMI screen. Any interest?

There's always a need for new display panels. The current offer doesn't cover all the needs - for example there is no bright (>= 400 nits), cheap (<70-90$), capacitive touchscreens available at the moment. Adafruit has a few bright ones but without a touchscreen. The ones that do have touchscreen ar...
by jeanleflambeur
Sat Apr 08, 2017 4:15 pm
Forum: Troubleshooting
Topic: Raspberry pi only detects one USB wifi adapter at startup
Replies: 1
Views: 460

Re: Raspberry pi only detects one USB wifi adapter at startu

I'm having the exact problem with 2 WN722n adapters.
Did you manage to find a solution to this?
by jeanleflambeur
Fri Apr 07, 2017 5:15 pm
Forum: Python
Topic: Bitwise LEFT shift
Replies: 9
Views: 1432

Re: Bitwise LEFT shift

You do 4 times this operation: a = b << 1 b is 0xff (or 11111111) Shifted left 1 bit you get 11111110 Note that b is not modified in the loop, so essentially your code does this 4 times: a = 0b11111110 If you expect 11110000, you have to do: for i in range(0, 4): b = b << 1 a = b OR simpler: a = b <...
by jeanleflambeur
Thu Feb 16, 2017 8:07 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Connect MPU 9250 to I2C
Replies: 6
Views: 12669

Re: Connect MPU 9250 to I2C

You have a typo in your command.
i2cget expects the bus number first and the i2c address second:

Code: Select all

sudo i2cget -y 1 0x68
The error you were getting was because i2cget was interpreting 0x68 as the bus number (hex 0x68 = decimal 104)
by jeanleflambeur
Thu Jan 26, 2017 8:42 am
Forum: Español
Topic: MPU-6050
Replies: 11
Views: 4413

Re: MPU-6050

It's probably that the SDA pin is shorted to ground.
Double check the connections.

Also, run i2cdetect with the sensor disconnected and see if it still detects everything.
by jeanleflambeur
Fri Dec 02, 2016 8:25 am
Forum: Python
Topic: Python Script is Using CPU and Memory a lot.
Replies: 6
Views: 3466

Re: Python Script is Using CPU and Memory a lot.

What does your file contain? A line of text like ready, not ready Are you sure it cannot be something else? If you have the text 'ready ' (notice the space) the program will busy loop opening a file, reading the line and closing it without taking any action. This will use 100% CPU. I recommend a sl...
by jeanleflambeur
Fri Dec 02, 2016 7:48 am
Forum: Python
Topic: Python Script is Using CPU and Memory a lot.
Replies: 6
Views: 3466

Re: Python Script is Using CPU and Memory a lot.

What does your file contain?
by jeanleflambeur
Fri Dec 02, 2016 7:44 am
Forum: Troubleshooting
Topic: GPIO not working as expected
Replies: 10
Views: 2338

Re: GPIO not working as expected

That code appears to be correct if the relay input is active LOW. If so, and if the relays are switching on and staying on, think about this: What is the operating voltage of the relay input? If it is designed for 5V (and the relay input control circuit runs at 5V) then it is possible that the GPIO...
by jeanleflambeur
Thu Dec 01, 2016 10:46 pm
Forum: Troubleshooting
Topic: GPIO not working as expected
Replies: 10
Views: 2338

Re: GPIO not working as expected

Seems to me like you're doing the opposite:

Code: Select all

# loop through pins and set mode and state to 'low'

for i in pinList:
    GPIO.setup(i, GPIO.OUT)
    GPIO.output(i, GPIO.HIGH)
The code is actually turning all the GPIOs ON instead of off.
by jeanleflambeur
Wed Nov 30, 2016 8:45 am
Forum: Raspberry Pi OS
Topic: Qt5 raspbian - errors, errors and more errors :(
Replies: 58
Views: 37320

Re: Qt5 raspbian - errors, errors and more errors :(

If you're using QT creator to cross-compile for the PI and to debug remotely you will have an issue with the host gdb being compiled without python support - on Ubuntu at least. The solution is to install gdb-multiarch on the host and configure it as the debugger for the kit, as detailed here: https...
by jeanleflambeur
Tue Oct 18, 2016 9:10 am
Forum: C/C++
Topic: How would you ...... in C ? (+ other C discussions)
Replies: 187
Views: 24171

Re: How would you ...... in C ?

Code: Select all

tm time_data;
time_data.tm_hour = 21;
char buffer[10];
strftime(buffer, sizeof(buffer), "%I%p", &time_data);
by jeanleflambeur
Thu Oct 13, 2016 8:32 pm
Forum: C/C++
Topic: Learning C++ for the first time. Feedback?
Replies: 6
Views: 1615

Re: Learning C++ for the first time. Feedback?

Hi, A few comments about the code you posted: 1. Member initialization is best expressed as this: TestClass::TestClass() : value(0) { } This has several advantages - it's faster as those members don't have to be default constructed and then assigned but instead are constructed with the desired value...
by jeanleflambeur
Tue Aug 30, 2016 7:43 pm
Forum: Camera board
Topic: Gimbal
Replies: 2
Views: 2536

Re: Gimbal

Not sure about CDROM motors, they woulld have to have a resistance of >5Ohm and not too high kV. Mounting the driver board next to the sensor board is interesting. However that would increase the size of the moving parts and would need more clearing. This is a big issue for my mini quad right now. F...
by jeanleflambeur
Mon Aug 29, 2016 9:29 pm
Forum: Camera board
Topic: Gimbal
Replies: 2
Views: 2536

Gimbal

I finished a 2 axis gimbal for the V2 camera. Here's a video of it in action: https://www.youtube.com/watch?v=wQypj7ti7Vw And more details + videos: https://jeanleflambeur.wordpress.com/2016/08/29/gimbal/ It weights 65 grams and BOM is of ~50e excluding the camera. The next step is to make a flexibl...
by jeanleflambeur
Sat Aug 06, 2016 9:10 pm
Forum: Advanced users
Topic: eglfs is 10x slower than EGL in X.org
Replies: 11
Views: 3079

Re: eglfs is 10x slower than EGL in X.org

You're welcome. Can you pls post the updated results if/when you have them? I'm really curious how it performs with opengl Es.

I'm also using the eglfs plugin on the pi but with qt quick which uses gl es by default. I get very good performance and was surprised by your results.
by jeanleflambeur
Sat Aug 06, 2016 8:49 pm
Forum: Advanced users
Topic: eglfs is 10x slower than EGL in X.org
Replies: 11
Views: 3079

Re: eglfs is 10x slower than EGL in X.org

(Posting from my phone so I'll be brief :)
Just looked at the QPainter docs and to use the OpenGL backend you have to render ina QOpenGLWidget instead of a QWidget.
So it does seem that all 3 methods tou tried used software rendering.
by jeanleflambeur
Sat Aug 06, 2016 4:05 pm
Forum: Advanced users
Topic: eglfs is 10x slower than EGL in X.org
Replies: 11
Views: 3079

Re: eglfs is 10x slower than EGL in X.org

It's very surprising that software rendering is as fast as using GLES. Can you measure the CPU usage in another terminal with top? I'm curious if you are CPU limited in the GLES test. You shouldn't as the draw calls should be batched by the painter. Try to also reuse the painter instead of creating ...
by jeanleflambeur
Sat Aug 06, 2016 8:57 am
Forum: Python
Topic: pigpio: callbacks stop working
Replies: 11
Views: 2022

Re: pigpio: callbacks stop working

Can you post some code, like the pigpio setup and the callback?
by jeanleflambeur
Sat Aug 06, 2016 8:01 am
Forum: Advanced users
Topic: eglfs is 10x slower than EGL in X.org
Replies: 11
Views: 3079

Re: eglfs is 10x slower than EGL in X.org

Print out the QSurfaceFormat in both cases, there might be differences in the default gl context initialization. For example the eglfs might use RGBA8888 and 24/32bpp depth while xcb RGB565 and 16bit depth. Also the eglfs might be using multisampling so check the sample count in the surface format. ...

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