Comment by arminb on LoRa point-to-point limitations
@clfmaris Yes, especially then you are obligated to respect duty-cycles. Annoying, but that's how it works. Otherwise there would be anarchism in frequency distribution. Those guidelines are completely...
View ArticleComment by arminb on Multiple self referencing in Entity Framework fails with...
Can we achieve this behaviour with data annotations only?
View ArticleComment by arminb on Simple select statement of SQLite takes more than 2 seconds
Show an example of a full query (BARCODE).
View ArticleComment by arminb on Using the C++ standard library in a Windows User Mode...
You are practically writing a user mode application. The name says it all, no reason to overthink. Just do what you would do in a "normal" application.
View ArticleComment by arminb on How to communicate with the reader using PC/SC
There is this question stackoverflow.com/q/35389657/1110642 With an alternate solution as well.
View ArticleComment by arminb on getopt does not order arguments in Windows
Thank you for the clarification that the sorting is not POSIX standard.
View ArticleComment by arminb on Is there any way to get 64-bit time_t in 32-bit programs...
On my 32 bit Linux 5.4 i can't call clock_gettime64 etc. It tells me undefined reference. What do I need to include/define/install in order for it to work?
View ArticleComment by arminb on Hey, I've recently learned recurrsion and i want to know...
You maybe need a \n in your printf statements to write the output.
View ArticleComment by arminb on Do I have to re-compile glibc 2.34 itself for full...
@KamilCuk no it's not. BTW if I change lchmod(...) to chmod(...) it works. I tend to believe this is a glibc 2.34 bug.
View ArticleAnswer by arminb for GET RESPONSE APDU Command
I don't know the framework you are using. I assume you use native WinSCard or PCSC Lite. When using SCardTransmit you have to make sure parameter pcbRecvLength is big enough for your response to fit in.
View ArticleAnswer by arminb for Android smart-card interface over USB
Sadly there is no abstraction layer like PC/SC in the native Android system. But you can utilize Android USB library to talk directly to the USB smart card reader.
View ArticleAnswer by arminb for Simple c code with sleep gives no output after execution
Add \n when printing to stdout.printf("inside main\n");The reason a \n is needed is because printf flushes data to stdout after \n was reached.You can print to stderr to see your data immediately,...
View ArticleRetrieve interface number in Windows driver
In my INF file I write following line to load interface number 01 from my composite USB device:%DeviceName%=Device_Install, USB\VID_XXXX&PID_XXXX&MI_01Now how do I retrieve this interface...
View ArticleAnswer by arminb for PCSC detect multiple smartcards
ACR-1252 reader has only one contact-less interface. When you try to connect (lay on) two contact-less smartcards at the same time, it becomes the responsibility of the reader firmware to choose which...
View ArticleAnswer by arminb for How to store the random seed generated from time(NULL)...
The function time() returns time_t type which can be any integer or real-floating type.But you can cast it to a known type:printf("%lld\n", (long long) time(NULL));If you just want to store the...
View ArticleAnswer by arminb for What does APDU response 910B mean for a DESFire EV2 card?
I saw HID's firmware source code for OMNIKEY readers and I can tell you it's a catastrophic mess. The OK5x21 reader is quite old, so I would suggest you to contact HID directly and request a firmware...
View ArticleAnswer by arminb for The same barcode is unexpectedly inserting into my database
Not entirely sure, but you should check you array like this for entries:if (count($data) > 0)
View ArticleAnswer by arminb for Does the Single Responsibility Principle work in OOP?
A class shall handle one topic, that's its single responsibility. A class Car could contain methods like startEngine() or attributes like weight:class Car{ int weight; void startEngine(); void...
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Answer by arminb for Can i use different timer channels when other channels...
The PWM and the I2C module are connected to the GPIO output via an multiplexer. By configuring related registers in your microcontroller you can decide which output will be passed through to the GPIO....
View ArticleAnswer by arminb for Add a hyperlink only to one column of a table
Add a counter to you inner loop:$counter = 0;foreach ( $value as $a ){ $url = get_template_directory_uri(); if ($counter == 1) { echo '<td><a href="'.$url.'/folder/' . $a . '">'....
View ArticleAnswer by arminb for Can't Download Full File in Python
First of all http://www.nmgncp.com/dark-wallpaper-1920x1080.html is an HTML document. Second when you try to download an image by direct URL (like:...
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Answer by arminb for What's mean 10B payload?
Semtech provides a calcualtor for its LoRa chip SX1272. When you fill in the parameters to the calculator from the example (LoRa for the Internet of Things):To give an example we assume SF12, BW125,...
View ArticleAnswer by arminb for Single channel gateway only detect first message
This sounds like your transmitter sends the messages using frequency-hopping, while your receiver does not handle it correctly (or the other way around).Definition of frequency-hopping found in chapter...
View ArticleUsing Data Annotations for SQLite in Entity Framework Core
I am using the Entity Framework Core to interface my SQLite database. I want to set a minimum and maximum range for the field ExitSide in my model Station:using...
View ArticleHow to obtain SCARD_ATTR_DEVICE_UNIT correctly
I am developing a smartcard UMDF windows driver. I would like to achieve following behaviour:When listing all connected readers by using API call SCardListReaders I want to retrieve the correct...
View ArticleAnswer by arminb for LoRa: application layer receiving fragmented packets for...
I am not familiar with the Ebyte ttl-1w-433 module but it uses the Semtech SX1276 chip. The SX1276 has a register RegPayloadLength (see SX1272 datasheet, page 114) which defines the payload length....
View ArticleAnswer by arminb for Substitutes for OSR Driver Loader (windows kernel driver )
Peter_Viscarola's comment from OSR community:Right now, you can't. We're in the process of trying to determine what to do with these hideously old, legacy, utilities. We haven't touched them in years...
View Articlebash: xargs passing variable
How can a global script variable be passed to the command of xargs? I tried it this way:TEST=hallo2echo "hallo" | xargs sh -c 'echo passed=$1 test=$TEST' shOutput:passed=hallo test=I know I could use...
View ArticleLooking for source code of __builtin_avr_delay_cycles called by _delay_ms in...
I was investigating the delay_ms function of avr-gcc. In delay.h I found its definition:void _delay_ms(double __ms){ double __tmp ;#if __HAS_DELAY_CYCLES && defined(__OPTIMIZE__) && \...
View ArticleAnswer by arminb for CCID protocol command types
The official CCID specification: LinkAlso helpful document (not public available): ISO 7816-3
View ArticleAnswer by arminb for Is checking the return value of printf important?
Not checking a return value is considered bad practice. BUT it is considered clean, if you explicitly state that you ignore the return value by adding (void) in front of the function call:(void)...
View ArticleHow to trigger pynput's GlobalHotkeys when all of the keys are released?
With pynput we can listen for global hotkeys like this:from pynput import keyboarddef on_activate_i(): print('<ctrl>+<alt>+i pressed')with...
View ArticleWrite HEX values to file in Windows batch
In Linux we can doecho -n -e '\x66\x6f\x6f'> test.txtto write HEX values to a file.How can this be done simply in Windows batch?
View ArticleWhy is GCC 11 compiler producing weird output when optimization is enabled?
Please take a look at this code:#include <stdio.h>#include <stdint.h>int main(){ uint8_t run = 1; /* Define variable of interest and set to random value */ uint32_t dwTime = 0xdeadc0de; /*...
View ArticleGraphViz Dot very long duration of generation
I have a tree structure I want to be generated by Dot. Each node has 4 edges to another 4 nodes. In sum there are about 1,000 nodes. If I try to generate it with Dot it takes a very long time (once I...
View ArticleRS232 Serial Pin Read in C in Linux
Ist there any possibility to read values from the pins of the COM Port? Any solution in C under Linux is appreciated!
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