95 lines
2.4 KiB
C
95 lines
2.4 KiB
C
#include "moisture_sensor.h"
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#include <stdio.h>
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#include <stdlib.h>
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/* the most readings one session can send; the sensor keeps its own copy */
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#define SENSOR_LIMIT 64
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static int total;
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static int sent;
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static int minute;
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static int level;
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static int sent_times[SENSOR_LIMIT];
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static int sent_levels[SENSOR_LIMIT];
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/*
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* srand() fixes where rand() starts, so the same seed sends the same readings
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* every run on one machine. Different C libraries may still send different ones.
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* Reference: https://en.cppreference.com/w/c/numeric/random/rand
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*/
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void sensor_start(unsigned int seed, int readings)
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{
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srand(seed);
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total = readings < 0 ? 0 : (readings > SENSOR_LIMIT ? SENSOR_LIMIT : readings);
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sent = 0;
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minute = 0;
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}
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static int next_level(void)
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{
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int kind = rand() % 20;
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if (kind < 2) {
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return -(1 + rand() % 5); /* a sensor fault */
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}
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if (kind < 4) {
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return 0; /* dry */
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}
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if (kind < 7) {
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return 101 + rand() % 20; /* saturated */
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}
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return 1 + rand() % 100;
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}
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int sensor_has_next(void)
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{
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if (sent >= total) {
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return 0;
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}
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minute = minute + 1 + rand() % 15;
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level = next_level();
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sent_times[sent] = minute;
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sent_levels[sent] = level;
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sent = sent + 1;
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printf("sensor: minute %d, level %d\n", minute, level);
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return 1;
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}
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int sensor_time(void)
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{
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return minute;
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}
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int sensor_level(void)
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{
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return level;
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}
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void sensor_check_log(int times[], int levels[], size_t count)
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{
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size_t want = 0;
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int i;
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for (i = 0; i < sent; i++) {
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if (sent_levels[i] < 0) {
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continue;
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}
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if (want == count) {
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printf("check: FAIL, minute %d (level %d) is valid but was not stored\n",
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sent_times[i], sent_levels[i]);
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return;
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}
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if (times[want] != sent_times[i] || levels[want] != sent_levels[i]) {
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printf("check: FAIL, slot %zu holds minute %d level %d; expected minute %d level %d\n",
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want, times[want], levels[want], sent_times[i], sent_levels[i]);
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return;
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}
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want = want + 1;
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}
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if (want != count) {
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printf("check: FAIL, count is %zu but the sensor sent %zu valid reading(s)\n", count, want);
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return;
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}
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printf("check: PASS, all %zu valid reading(s) stored in order\n", count);
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}
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