From 9761a0be9e7d8610c38779e2daac12e98ad55c3b Mon Sep 17 00:00:00 2001
From: jweigele <jweigele@local>
Date: Fri, 14 Jul 2023 12:22:44 -0700
Subject: [PATCH 1/1] Initial commit, still prints a bunch of debug code but
 does work

---
 CMakeLists.txt     |   3 ++
 aqi_calc.c         | 124 +++++++++++++++++++++++++++++++++++++++++++++
 component.mk       |   1 +
 include/aqi_calc.h |   8 +++
 4 files changed, 136 insertions(+)
 create mode 100644 CMakeLists.txt
 create mode 100644 aqi_calc.c
 create mode 100644 component.mk
 create mode 100644 include/aqi_calc.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..3c0ad24
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,3 @@
+idf_component_register(SRCS "aqi_calc.c"
+INCLUDE_DIRS "include"
+REQUIRES driver)
diff --git a/aqi_calc.c b/aqi_calc.c
new file mode 100644
index 0000000..97f3bdf
--- /dev/null
+++ b/aqi_calc.c
@@ -0,0 +1,124 @@
+#include "aqi_calc.h"
+
+typedef struct aqi_lookup_s  {
+    uint16_t    aqi_low;
+    uint16_t    aqi_high;
+    uint16_t       pm10_low;
+    uint16_t       pm10_high;
+    uint16_t       pm25_low;
+    uint16_t       pm25_high;
+} aqi_lookup_t;
+
+enum lookup_type {LOOKUP_PM10, LOOKUP_PM25};
+
+static const aqi_lookup_t AQI_LOOKUP_TABLE[] = {
+    {
+        .aqi_low = 0,
+        .aqi_high = 50,
+        .pm10_low = 0,
+        .pm10_high = 54,
+        .pm25_low = 0,
+        .pm25_high = 120,
+    },
+    {
+        .aqi_low = 51,
+        .aqi_high = 100,
+        .pm10_low = 55,
+        .pm10_high = 154,
+        .pm25_low = 121,
+        .pm25_high = 354,
+    },
+    {
+        .aqi_low = 101,
+        .aqi_high = 150,
+        .pm10_low = 155,
+        .pm10_high = 254,
+        .pm25_low = 355,
+        .pm25_high = 554,
+    },
+    {
+        .aqi_low = 151,
+        .aqi_high = 200,
+        .pm10_low = 255,
+        .pm10_high = 354,
+        .pm25_low = 555,
+        .pm25_high = 1504,
+    },
+    {
+        .aqi_low = 201,
+        .aqi_high = 300,
+        .pm10_low = 355,
+        .pm10_high = 424,
+        .pm25_low = 1505,
+        .pm25_high = 2504,
+    },
+    {
+        .aqi_low = 301,
+        .aqi_high = 500,
+        .pm10_low = 425,
+        .pm10_high = 604,
+        .pm25_low = 2505,
+        .pm25_high = 5004,
+    },
+};
+
+
+float linear_calc(uint16_t value, aqi_lookup_t lookup_row, int lookup_type){
+    uint16_t lookup_low, lookup_high, aqi_low, aqi_high;
+    if (lookup_type == LOOKUP_PM10){
+        lookup_low = lookup_row.pm10_low;
+        lookup_high = lookup_row.pm10_high;
+    } else if (lookup_type == LOOKUP_PM25){
+        lookup_low = lookup_row.pm25_low;
+        lookup_high = lookup_row.pm25_high;
+    } else {
+        lookup_low = 0;
+        lookup_high = 0;
+    }
+    // convenience
+    aqi_low = lookup_row.aqi_low;
+    aqi_high = lookup_row.aqi_high;
+
+    float retval = ((aqi_high - aqi_low)/((float)(lookup_high - lookup_low))*(value - lookup_low) + aqi_low);
+    printf("calculated aqi of %f, returning\n", retval);
+    return retval;
+}
+
+float aqi_calc_pm10(uint16_t pm10){
+    // precision is integer, so div 100
+    // ex. 2543 / 100 = 25 (real value: 25)
+    pm10 /= 100;
+    int i = 0;
+    while (i < 6){
+        if (pm10 < AQI_LOOKUP_TABLE[i].pm10_high ){
+            printf("found lookup index for pm10, %d\n", i);
+            break;
+        }
+        i++;
+    }
+    if (pm10 > AQI_LOOKUP_TABLE[i].pm10_high){
+        printf("pm10 too high for aqi lookup, this should never happen %d > %d\n", pm10, AQI_LOOKUP_TABLE[i].pm10_high );
+        return 0.0;
+    }
+    return linear_calc(pm10, AQI_LOOKUP_TABLE[i], LOOKUP_PM10);
+}
+
+float aqi_calc_pm25(uint16_t pm25){
+    // precision is one decimal, so div 10:
+    // ex. 2543 / 10 = 254 (real value: 25.4)
+    pm25 /= 10;
+    printf("modified pm25: %d\n", pm25);
+    int i = 0;
+    while (i < 6){
+        if (pm25 < AQI_LOOKUP_TABLE[i].pm25_high ){
+            printf("found lookup index for pm25, %d\n", i);
+            break;
+        }
+        i++;
+    }
+    if (pm25 > AQI_LOOKUP_TABLE[i].pm25_high){
+        printf("pm25 too high for aqi lookup, this should never happen %d > %d\n", pm25, AQI_LOOKUP_TABLE[i].pm25_high );
+        return 0.0;
+    }
+    return linear_calc(pm25, AQI_LOOKUP_TABLE[i], LOOKUP_PM25);
+}
diff --git a/component.mk b/component.mk
new file mode 100644
index 0000000..346dafd
--- /dev/null
+++ b/component.mk
@@ -0,0 +1 @@
+# Use defaults
diff --git a/include/aqi_calc.h b/include/aqi_calc.h
new file mode 100644
index 0000000..57a21c2
--- /dev/null
+++ b/include/aqi_calc.h
@@ -0,0 +1,8 @@
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdbool.h>
+
+
+float aqi_calc_pm10(uint16_t pm10);
+float aqi_calc_pm25(uint16_t pm25);
+
-- 
2.30.2