From 9405b3d8b8204a42bf58b74f940cda9ff19812e5 Mon Sep 17 00:00:00 2001
From: Maximilian Grau <maximilian.grau@st.ovgu.de>
Date: Mon, 1 Nov 2021 16:56:50 +0100
Subject: [PATCH] Save/load state of BME680 to intern EEPROM

---
 src/bmeSPI.cxx | 89 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 77 insertions(+), 12 deletions(-)

diff --git a/src/bmeSPI.cxx b/src/bmeSPI.cxx
index 6499172..1f6e422 100644
--- a/src/bmeSPI.cxx
+++ b/src/bmeSPI.cxx
@@ -3,12 +3,14 @@
 #include "main.h"
 #include "semphr.h"
 #include "spi.h"
+#include "stm32l1xx_hal_flash_ex.h"
 #include "task.h"
 
 #include <cstring>
 
 #include "BME68x-Sensor-API/bme68x.h"
 #include "BSEC/bsec_interface.h"
+#include "SSD1306_SPI.hpp"
 #include "oled-driver/Renderer.hpp"
 
 extern QueueHandle_t spiMutex;
@@ -51,8 +53,10 @@ float iaq, rawTemperature, pressure, rawHumidity, gasResistance, stabStatus, run
 uint8_t iaqAccuracy, staticIaqAccuracy, co2Accuracy, breathVocAccuracy, compGasAccuracy,
     gasPercentageAcccuracy;
 
-// uint8_t bsecState[BSEC_MAX_STATE_BLOB_SIZE];
-// uint8_t workBuffer[BSEC_MAX_WORKBUFFER_SIZE];
+uint8_t bsecState[BSEC_MAX_STATE_BLOB_SIZE];
+uint8_t workBuffer[BSEC_MAX_WORKBUFFER_SIZE];
+
+constexpr uintptr_t EepromAddress = FLASH_EEPROM_BASE;
 
 void setChipSelect(bool state)
 {
@@ -310,33 +314,94 @@ void printBmeSensorData()
 {
     renderer.clearAll();
 
-    snprintf(buffer, MaximumChars,
-             "%d°C, %luhPa, %d%%\nIAQ: %d, Accuracy: %d\nCO2: %dppm\n%d, %d, %d - %lukOhm",
+    const auto MaxTextWidth = renderer.getLineWidth("1000hPa");
+
+    snprintf(buffer, MaximumChars, "%d°C\n%luhPa\n%d%%\nAcc: %d",
              static_cast<int>(temperature),            //
              bmeData[numberOfData - 1].pressure / 100, //
              static_cast<int>(humidity),               //
-             static_cast<int>(iaq),                    //
-             iaqAccuracy,                              //
-             static_cast<int>(co2Equivalent),          //
-             bmeData[numberOfData - 1].status,         //
-             bmeData[numberOfData - 1].gas_index,      //
-             bmeData[numberOfData - 1].gas_wait,       //
-             bmeData[numberOfData - 1].gas_resistance / 1000);
+             iaqAccuracy);
+    renderer.print({128, 0}, buffer, Renderer::Alignment::Right);
+    renderer.drawVerticalLine(OledWidth - MaxTextWidth - 2, 0, OledPages - 1);
 
-    renderer.print({0, 0}, buffer);
+    if (iaqAccuracy == 0)
+        snprintf(buffer, MaximumChars, "IAQ:---\n---ppm\n");
+    else
+        snprintf(buffer, MaximumChars, "IAQ:%d\n%dppm\n",
+                 static_cast<int>(iaq), //
+                 static_cast<int>(co2Equivalent));
+
+    renderer.print({0, 0}, buffer, Renderer::Alignment::Left, 2);
     renderer.render();
 }
 
+void readStateFromEeprom()
+{
+
+    uint8_t sizeOfData = *reinterpret_cast<uint8_t *>(EepromAddress);
+
+    if (sizeOfData != BSEC_MAX_STATE_BLOB_SIZE)
+        return;
+
+    // Existing state in EEPROM
+    for (uint8_t i = 0; i < BSEC_MAX_STATE_BLOB_SIZE; i++)
+    {
+        bsecState[i] = *reinterpret_cast<uint8_t *>(EepromAddress + i + 1);
+    }
+
+    bsec_set_state(bsecState, BSEC_MAX_STATE_BLOB_SIZE, workBuffer, sizeof(workBuffer));
+}
+
+void writeStateToEeprom()
+{
+    if (iaqAccuracy != 3)
+        return;
+
+    uint32_t numberSerializedState = BSEC_MAX_STATE_BLOB_SIZE;
+
+    auto status = bsec_get_state(0, bsecState, BSEC_MAX_STATE_BLOB_SIZE, workBuffer,
+                                 BSEC_MAX_STATE_BLOB_SIZE, &numberSerializedState);
+
+    if (status != BSEC_OK)
+        return;
+
+    HAL_FLASHEx_DATAEEPROM_Unlock();
+
+    // write size
+    HAL_FLASHEx_DATAEEPROM_Program(FLASH_TYPEPROGRAMDATA_BYTE, EepromAddress,
+                                   BSEC_MAX_STATE_BLOB_SIZE);
+
+    for (uint8_t i = 0; i < BSEC_MAX_STATE_BLOB_SIZE; i++)
+    {
+        HAL_FLASHEx_DATAEEPROM_Program(FLASH_TYPEPROGRAMDATA_BYTE, EepromAddress + i + 1,
+                                       bsecState[i]);
+    }
+
+    HAL_FLASHEx_DATAEEPROM_Lock();
+}
+
 //--------------------------------------------------------------------------------------------------
 extern "C" void sensorTask(void *)
 {
     initDisplay();
     bmeSensorInit();
+    readStateFromEeprom();
+
+    uint16_t counter = 0;
 
     while (1)
     {
         bmeRun();
         bsecRun();
         printBmeSensorData();
+
+        if (counter++ >= 100)
+        {
+            initDisplay();
+            counter = 0;
+            writeStateToEeprom();
+        }
+
+        vTaskDelay(pdMS_TO_TICKS(10));
     }
 }
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