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by markkuk
Sat Aug 01, 2020 8:28 am
Forum: Networking and servers
Topic: Pi WiFi with ESP8266?
Replies: 23
Views: 894

Re: Pi WiFi with ESP8266?

cleverca22 wrote:
Fri Jul 31, 2020 8:58 pm
firmware to do that might already exist, and may implement something linux supports out of the box
Yes, it's called ESP8266 AT, documentation: https://www.espressif.com/sites/default ... set_en.pdf
by markkuk
Sat Aug 01, 2020 7:53 am
Forum: Beginners
Topic: Loading Screenly or other programs
Replies: 2
Views: 136

Re: Loading Screenly or other programs

Screenly Open Source Edition can be added to an existing Raspberry Pi OS Lite installation. The support page referenced by RGJ-PI applies to the commercial Screenly Pro version.
by markkuk
Wed Jul 29, 2020 12:41 pm
Forum: Automation, sensing and robotics
Topic: Is there a way to get an altitude and azimuth sensor connected to the RPi without soldering?
Replies: 5
Views: 437

Re: Is there a way to get an altitude and azimuth sensor connected to the RPi without soldering?

Navi_21 wrote:
Tue Jul 28, 2020 2:17 pm
So I was wondering if you guys knew about any sensors that I could attach to my RPi without soldering. Thanks!
Any of the Adafruit Stemma QT/Sparkfun qwiic compatible sensor boards together with a suitable cable will work without any soldering.
by markkuk
Thu Jul 02, 2020 5:03 am
Forum: Beginners
Topic: Yet another question about LEDs and resistors...
Replies: 7
Views: 307

Re: Yet another question about LEDs and resistors...

If the LED is bright enough with the 220 Ohm resistor, then just use that one. The purpose of the resistor is to prevent too large currents, so using one that's larger than the theoretical optimum isn't a problem.
by markkuk
Sat Jun 27, 2020 8:50 am
Forum: Advanced users
Topic: Potential Biometric Login?
Replies: 8
Views: 402

Re: Potential Biometric Login?

Raspbian/Raspberry Pi OS includes the Freedesktop.org fprint library and libpam-fprintd module for PAM. List of supported devices: https://fprint.freedesktop.org/supported-devices.html
by markkuk
Wed Jun 17, 2020 11:12 am
Forum: C/C++
Topic: SmartHome IoT: RPi server for website and control esp8266 wifi clients
Replies: 14
Views: 1005

Re: SmartHome IoT: RPi server connect to esp8266 wifi clients

If you want to continue using Qt, there's QtWebApp library. Other possibilities include: Boost Beast , this one should be included in Raspberry Pi OS as part of the libboost-all-dev package. Drogon , leader in the TechEmpower performance rankings . Cutelyst , another Qt based framework. loads of oth...
by markkuk
Mon Jun 15, 2020 6:48 am
Forum: Raspberry Pi OS
Topic: How to create an installer for my app for Raspberry Pi OS?
Replies: 1
Views: 161

Re: How to create an installer for my app for Raspberry Pi OS?

I'm the author of Adventuron Classroom and I'd like to package the application so that it can be accessed via the Pi package manager. Raspberry Pi OS is based on Debian Linux and uses the Debian package management system. https://wiki.debian.org/HowToPackageForDebian is there a guide for having it ...
by markkuk
Wed Jun 10, 2020 9:51 am
Forum: C/C++
Topic: Bug Report - misbehaving little C++ code
Replies: 24
Views: 1308

Re: Bug Report - misbehaving little C++ code

I tried opening 16 LXTerminal windows running your program, I don't get any blank windows and the system stays responsive. This is on a 4GB Pi4 running 64bit RaspberryPiOS.
2020-06-10-123202_1920x1080_scrot.jpg
2020-06-10-123202_1920x1080_scrot.jpg (110.92 KiB) Viewed 1145 times
by markkuk
Wed Jun 10, 2020 5:28 am
Forum: C/C++
Topic: Bug Report - misbehaving little C++ code
Replies: 24
Views: 1308

Re: Bug Report - misbehaving little C++ code

It looks like a LXTerminal problem. Its wiki page says: "All instances of program share the same process to reduce memory usage", so there's a single process trying to keep up with all the output from your programs (and failing).
by markkuk
Tue Jun 02, 2020 5:14 pm
Forum: Networking and servers
Topic: i am on the search for a X2go solution for RASPI
Replies: 3
Views: 1469

Re: i am on the search for a X2go solution for RASPI

Choose "Custom desktop" as your session type and set "startlxde-pi" as the command to get the standard Raspberry Pi desktop on Raspbian/Raspberry Pi OS.
by markkuk
Tue Jun 02, 2020 5:03 am
Forum: Java
Topic: Is there reason why is there just Java 11?
Replies: 4
Views: 767

Re: Is there reason why is there just Java 11?

OpenJDK 11 is the latest Long Term Support (LTS) release and the next LTS release will be OpenJDK 17. Releases 12 - 16 have only 6 month support period, which is too short for inclusion in Debian stable.
by markkuk
Mon Jun 01, 2020 6:08 pm
Forum: Beginners
Topic: How to use the built-in RNG with python
Replies: 26
Views: 929

Re: How to use the built-in RNG with python

Your code reads a single byte from the random stream, then prints that byte again and again. The problem isn't with the random number generator, it's in your code. Try this instead: with open('/dev/urandom', 'rb') as f: while True: print(int.from_bytes(f.read(4), byteorder='little', signed=True))
by markkuk
Fri May 29, 2020 9:54 am
Forum: Python
Topic: Trouble writing BME280 sensor data to mariadb
Replies: 10
Views: 942

Re: Trouble writing BME280 sensor data to mariadb

nowtemp=28.12 try: cursor.execute("INSERT INTO testw(TEMP1) VALUES(%s)", (nowtemp)) mariadb_connection.commit() This gives an error from mariadb saying that I have an error in my SQL syntax error near %s). The substitution values for parameters in the query must be given as a sequence even when the...
by markkuk
Thu May 28, 2020 9:16 am
Forum: Python
Topic: Raspberry OS: ModuleNotFoundError: No module named 'RPi'
Replies: 4
Views: 328

Re: Raspberry OS: ModuleNotFoundError: No module named 'RPi'

I'm guessing it's the usual Python2 vs.Python3 problem: you have installed only the Python2 version of RPi.GPIO and you're running the script with Python3. Install the Python3 version of the package with:

Code: Select all

sudo apt update
sudo apt install python3-rpi.gpio
by markkuk
Wed May 27, 2020 5:03 am
Forum: Advanced users
Topic: RPI to arduino(MKR 1010) Master-Slave Ethernet Protocol.
Replies: 4
Views: 272

Re: RPI to arduino(MKR 1010) Master-Slave Ethernet Protocol.

TCP/IP Ethernet networks are peer-to-peer, not master-slave. There is no "creator of the network". Assign a different IPv4 address for each device, and use standard socket communications between the devices.
by markkuk
Sun May 24, 2020 8:37 pm
Forum: Beginners
Topic: Tf and micro cards
Replies: 1
Views: 154

Re: Tf and micro cards

TF is an old name for MicroSD cards. Originally TF was a proprietary form factor by Sandisk and Motorola, but later it was included in official standards published by the SD Association as MicroSD. See: https://en.wikipedia.org/wiki/SD_card#2 ... icro_cards.
by markkuk
Sat May 23, 2020 7:35 am
Forum: Camera board
Topic: C or CS mount to M42
Replies: 8
Views: 549

Re: C or CS mount to M42

Are you sure it's really a M42 mount instead of a T-mount? Both are 42mm in diameter but the thread pitch is different. T-mount is commonly used in telescope and microscope attachments.
by markkuk
Fri May 22, 2020 9:23 pm
Forum: General discussion
Topic: I got a new Raspberry Pi 3 Model B+ Board (3B+)
Replies: 6
Views: 378

Re: I got a new Raspberry Pi 3 Model B+ Board (3B+)

Thanks a lot. But this link is for debian version. Is it the same than the Operating System installed on my microSD card please? You're the only person that can find that out, so try the commands in the article. If they don't work at all, then you are running something really strange like RiscOS. A...
by markkuk
Mon May 18, 2020 12:43 pm
Forum: Automation, sensing and robotics
Topic: Using a 12V relay to control pi power state
Replies: 3
Views: 245

Re: Using a 12V relay to control pi power state

Or is the GPIO just triggering the state change and the pi itself would need constant power. Yes, you must provide 5V power to the Pi and the GPIO pins are only used to trigger shutdown/reboot. With the relay, wouldn't I need some sort of resistor or something to bring down the voltage from 12V on ...
by markkuk
Wed May 13, 2020 11:49 am
Forum: General discussion
Topic: keypad connection
Replies: 4
Views: 237

Re: keypad connection

You need a Linux input device driver to make the keypad work as a normal keyboard. Fortunately a driver for matrix keypads exists already in Raspbian, so you don't have to write one by yourself. All you need is a device tree overlay file that defines the connections between GPIO lines and the rows a...
by markkuk
Mon May 11, 2020 5:55 am
Forum: General discussion
Topic: Java 9 arrays for loop
Replies: 4
Views: 226

Re: Java 9 arrays for loop

I suspect most online courses on Java programming would cover this within the first semester, but I don't know which to recommend. Maybe https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-092-introduction-to-programming-in-java-january-iap-2010/ I would recommend this one: ht...
by markkuk
Tue Apr 28, 2020 12:27 pm
Forum: Python
Topic: Using Python on raspberry pi 3 b+
Replies: 2
Views: 230

Re: Using Python on raspberry pi 3 b+

The default Python IDE in Raspbian Buster is Thonny and the other recommended one is Mu. If you absolutely must have IDLE, you can install it with the usual package management tools.
by markkuk
Fri Apr 24, 2020 8:45 am
Forum: Python
Topic: Traffic light display (UK Pattern) using LEDs and Python
Replies: 15
Views: 623

Re: Traffic light display (UK Pattern) using LEDs and Python

But could the timing get out of sync? (i.e. is 2 sec exactly 2.000000 etc seconds Yes, the lights will get out of sync. In Python 3.5 or later, time.sleep() is guaranteed to sleep at least the specified time, but the time can be longer than specified "by an arbitrary amount". You should use a singl...
by markkuk
Mon Apr 20, 2020 8:03 am
Forum: Advanced users
Topic: Is it possible to get MySQL on the pi?
Replies: 5
Views: 385

Re: Is it possible to get MySQL on the pi?

LonlyGamerX wrote:
Sun Apr 19, 2020 10:15 pm
So is it possible to get MySQL (NOT MariaDB) on your pi.
Oracle doesn't provide binary packages for ARM Linux, so your only choice would be to download the source code and compile it by yourself. The instructions are here: https://dev.mysql.com/doc/refman/8.0/en ... ation.html
by markkuk
Thu Apr 16, 2020 6:21 am
Forum: Python
Topic: JSON finding the right key
Replies: 2
Views: 162

Re: JSON finding the right key

Is there a way to get separate key/values for all of the things at the end of the JSON? ie, how do I pull out the value of "wind_chill" or "air_temperture"? The value for 'obs' is a single-element list that contains a regular Python dictionary that can be accessed by keyword: print(data['obs'][0]['...

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