PaulStoffregen

// Demo video: https://www.youtube.com/watch?v=mbqrDqTsEf0

#include <Audio.h>

AudioInputAnalog         audioIn;
AudioAnalyzeToneDetect   row1;     // 7 tone detectors are needed
AudioAnalyzeToneDetect   row2;     // to receive DTMF dial tones
AudioAnalyzeToneDetect   row3;
AudioAnalyzeToneDetect   row4;
AudioAnalyzeToneDetect   column1;

PaulStoffregen

// Test whether seek() works after reading to end of file
//
// https://twitter.com/fast_code_r_us/status/1285180217720528896

#include <SD.h>

const int csPin = 10;

void setup() {
  Serial.begin(9600);

PaulStoffregen

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/select.h>
#include <unistd.h>
#include <errno.h>

PaulStoffregen

// TwitchyBun algorithm, Dec 4 2019
// https://www.twitch.tv/ninjabunny9000

// gcc -Wall -o TwitchyBun TwitchyBun.c && ./TwitchyBun

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

PaulStoffregen

// A very quick entropy test.  Run on Teensy 3.x or Teensy LC.
// https://twitter.com/DavidInOregon/status/937304504210423808

volatile uint8_t val=0;
volatile bool newval=false;

void setup() {
  SIM_SCGC5 |= SIM_SCGC5_LPTIMER;
  LPTMR0_CSR = 0b10000100;
  LPTMR0_PSR = 0b00000101;  // PCS=01 : 1 kHz clock