nerdralph

/* Fridge Door Alarm for the ATTiny13[A]
 *
 * Functionality:
 *
 * Door opens, door open chime.
 * After 60 seconds, door-open warning beep.
 * If door still open, warning beeps every 30 seconds.
 * After 5 minutes, continous alarm signal.
 * Door closes, door close chime.
 * If Silent Running pressed, no door chimes for ONE operation.

nerdralph

// Ralph Doncaster 2020 public domain software
// generate lookup table for powers of sqrt(2)
#include <stdio.h>
#include <math.h>

int main()
{
    double sqrt2 = sqrt(2.0);
    for (double d = 2; d <= 16; d += 1) {
        printf( "1.414^%d = %lf\n", (int)d, pow(sqrt2, d) );

nerdralph

// Ralph Doncaster 2020 public domain software
// calculate the 64-bit inverse of odd integers
#include <stdio.h>
#include <stdint.h>

#define END_RANGE 9999

int main()
{
    uint64_t neg1 = (uint64_t) -1LL;

nerdralph

sudo ./openocd -f ~/devel/dap/cmsis-dap.cfg 
xPack OpenOCD, x86_64 Open On-Chip Debugger 0.10.0+dev (2020-10-13-17:27)
Licensed under GNU GPL v2
For bug reports, read
	http://openocd.org/doc/doxygen/bugs.html
Info : CMSIS-DAP: SWD  Supported
Info : CMSIS-DAP: FW Version = 1.0.0
Info : CMSIS-DAP: Interface Initialised (SWD)
Info : SWCLK/TCK = 1 SWDIO/TMS = 1 TDI = 0 TDO = 0 nTRST = 0 nRESET = 1
Info : CMSIS-DAP: Interface ready

nerdralph

#include <stdint.h>

extern __flash const uint8_t digital_pin_to_bit_mask_PGM[];

uint8_t read_array(uint8_t i)
{
  return digital_pin_to_bit_mask_PGM[i];        // bug: uses ld
  // return *(digital_pin_to_bit_mask_PGM + i);    // uses lpm
}