dennisfen

Enabling bluetooth

[Pi 3B (Non-Plus) / Pi Zero W ONLY]

As of kernel package, linux-raspberrypi-4.14.59-1, support for notifying the kernel of the Broadcom bluetooth device through the device tree has been enabled.

There is no longer a need for btattach, which makes the lives of everyone easier. There is also no need to fall back to hciattach for better performance, as the

dennisfen

void remove_list_entry (entry) {
  // we will use indirect pointer to traverse the list
  indirect = &head;
  
  // search the list for needed entry using indirect pointer for traversal
  while ((*indirect) != entry) {
     indirect = &(*indirect)->next;
  }
 
  // entry and indirect pointer point to the same location

dennisfen

all:
	gcc -std=c11 -O0 -ggdb -o work main.c

dennisfen

all:
	gcc -std=c11 -O0 -ggdb -o shell shell.c
  

dennisfen

all:
	g++ -std=c++14 -o derivative derivative.cpp

dennisfen

#include <iostream>
#include <ios>
#include <regex>
#include <cstdlib>
#include <string>
#include <errno.h>
#include <cmath>

std::string parse_input(const std::string& input) {
    std::cout << std::boolalpha;

dennisfen

class session {
  tcp::socket socket_;
  array<unsigned char, 1024> data_;
  //...
  void do_read() {
    socket_.async_read_some (buffer(data_),
                             [this](std::error_code ec, std::size_t n) {
                               // do stuff
                               //...
                               do_read();

dennisfen

# it calls unix ping util and checks its return status
import subprocess

def pingIt(host):
    try:
        output = subprocess.check_output("ping -c 1 " + host, shell=True)
    except Exception, e:
        return False

    return True

dennisfen

#include <vector>
#include <random>

using namespace std;

void print_vector(const vector<int>&);
vector<int> merge(const vector<int>&, const vector<int>&);
                                                                                                                               
vector<int> merge_sort_recursive(const vector<int>& v) {                                                                       
    if (v.size() <= 1)                                                                                                         

dennisfen

## /etc/udev/rules.d/71-xusbdfwu.rules 
# version 0003
ATTRS{idVendor}=="03fd", ATTRS{idProduct}=="0008", MODE="666"
SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="03fd", ATTRS{idProduct}=="0007", RUN+="/sbin/fxload -v -t fx2 -I /usr/share/xusbdfwu.hex -D $tempnode"
SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="03fd", ATTRS{idProduct}=="0009", RUN+="/sbin/fxload -v -t fx2 -I /usr/share/xusb_xup.hex -D $tempnode"
SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="03fd", ATTRS{idProduct}=="000d", RUN+="/sbin/fxload -v -t fx2 -I /usr/share/xusb_emb.hex -D $tempnode"
SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="03fd", ATTRS{idProduct}=="000f", RUN+="/sbin/fxload -v -t fx2 -I /usr/share/xusb_xlp.hex -D $tempnode"
SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="03fd", ATTRS{idProduct}=="0013", RUN+="/sbin/fxload -v -t fx2 -I /usr/share/xusb_xp2.hex -D $tempnode"
SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="03fd", ATTRS{idProduct}=="0015", RUN+="/sbin/fxload -v -t fx2 -I /usr/share/xusb