diff options
Diffstat (limited to 'src/tempmodule/main.ino')
| -rw-r--r-- | src/tempmodule/main.ino | 70 |
1 files changed, 1 insertions, 69 deletions
diff --git a/src/tempmodule/main.ino b/src/tempmodule/main.ino index b07365d..e15cd93 100644 --- a/src/tempmodule/main.ino +++ b/src/tempmodule/main.ino @@ -22,13 +22,8 @@ #include <WiFiUdp.h> #include <stddef.h> #include <string.h> -#include <inttypes.h> #include "indicator.h" - -struct temptuple { - short res; /* Resistance in ohms. */ - short temp; /* Temperatures in 0.1°K. */ -}; +#include "temperature.h" static const unsigned int iled = 2; static const unsigned int analog = A0; @@ -46,9 +41,6 @@ static int udp_flush(void); static void wifi_connect(const char * const ssid, const char * const password, const char doblink, const int ledpin); static void blink_led(const int pin, const int ontime, const int offtime); static void discover_client(void); -static int get_resistance(int64_t vt, int64_t ra); -static int get_temperature(int res); -static int get_temp_subrange(short a, short b, int res); void setup(void) { @@ -163,63 +155,3 @@ static void discover_client(void) delay(95); } while (!done); } - -/* - * formula by applying Ohms law: - * - * Rt: Thermistor resistance - * Ra: Voltage divider resistor - * Vt: Tap voltage - * Vcc: Input Voltage (3.31V) - * - * Rt = Ra * Vcc / Vt - Ra - * - * Using 64-bit arithmetic as 32-bit would overflow. - * On WeMOS D1 Mini the A0 reads 3.2V as 1023; our Vcc is 3.31V - * The correct value of the reference volume obtained by measuring - * resistances with a multimeter, taking the ADC reading and applying - * Ohm's law. - * We shift the range by one to avoid division by zero. - */ -static int get_resistance(int64_t vt, int64_t ra) -{ - ++vt; - return ra * 1081 / vt - ra; -} - -static int get_temperature(int res) -{ - int ret; - size_t i; - static const struct temptuple lt[] = { - {1495, 2630}, {1630, 2730}, {1772, 2830}, {1922, 2930}, - {2080, 3030}, {2245, 3130}, {2417, 3230}, {2597, 3330}, - {2785, 3430}, {2980, 3530}, {3182, 3630}, {3392, 3730}, - {3607, 3830}}; - - ret = -1; - - for (i = 0; i < 12; ++i) { - /* If we have a matching resistance, nothing to calculate. */ - if (res == lt[i].res) { - ret = lt[i].temp; - break; - } else if (res == lt[i + 1].res) { - ret = lt[i + 1].temp; - break; - /* If no matching resistance is found, calculate temp from subrange. */ - } else if (res > lt[i].res && res < lt[i + 1].res) { - ret = lt[i].temp + get_temp_subrange(lt[i].res, lt[i + 1].res, res); - break; - } - } - - return ret; - -} - -/* Returns the last 0-10 part of the temperature, in 0.1°K. */ -static int get_temp_subrange(short a, short b, int res) -{ - return (res - a) * 100 / (b - a); -} |