From 7cc658bc2e1f314ed85ed3cc55aa44fe424ecfda Mon Sep 17 00:00:00 2001
From: RedHawk <tadshig@gmail.com>
Date: Sun, 11 Jun 2023 21:45:22 +0300
Subject: [PATCH] temp sensor: [#61] Added placeholder for the sensor
 interface.

---
 .../threads/temperature/SensorTempSHT20.cpp   | 57 +++++++++++++++++++
 .../src/threads/temperature/SensorTempSHT20.h | 28 +++++++++
 2 files changed, 85 insertions(+)
 create mode 100644 source/shoh/src/threads/temperature/SensorTempSHT20.cpp
 create mode 100644 source/shoh/src/threads/temperature/SensorTempSHT20.h

diff --git a/source/shoh/src/threads/temperature/SensorTempSHT20.cpp b/source/shoh/src/threads/temperature/SensorTempSHT20.cpp
new file mode 100644
index 0000000..b3cc327
--- /dev/null
+++ b/source/shoh/src/threads/temperature/SensorTempSHT20.cpp
@@ -0,0 +1,57 @@
+/*
+ * SensorTempSHT20.cpp
+ *
+ *  Created on: 16 May 2023
+ */
+
+#include "SensorTempSHT20.h"
+#include "FreeRTOS.h"
+#include "task.h"
+#include "Log.h"
+
+//D6U9H:
+//D - Digital (i2c)
+//6 - 2016 year of production
+//U9H - Sensirion undecodable crap
+//Address: 0x40
+
+//Trigger T measurement | hold master    | 1110 0011 - 0xe3
+//Trigger T measurement | no hold master | 1111 0011 - 0xf3
+//Write user register   |                | 1110 0110 - 0xe6
+//Read user register    |                | 1110 0111 - 0xe7
+//Soft reset            |                | 1111 1110 - 0xfe
+
+//Use hold master - read(com = 0xe3)
+//Reading is done via 3 bytes.
+//WRITE: I2C address + write | read command
+//READ: Data (MSB) | Data (LSB) + Stat. | Checksum
+
+
+SensorTempSHT20::SensorTempSHT20(I2C* pi2c)
+: _pi2c(pi2c), _dev_addr(0x40)
+{}
+
+SensorTempSHT20::~SensorTempSHT20()
+{}
+/*
+const int16_t POLYNOMIAL = 0x131;
+
+int8_t SHT2x_CheckCrc(int8_t data[], int8_t nbrOfBytes, int8_t checksum)
+{
+    int8_t crc = 0;
+    int8_t bit;
+    int8_t byteCtr;
+    //calculates 8-Bit checksum with given polynomial
+    for (byteCtr = 0; byteCtr < nbrOfBytes; ++byteCtr)
+    {
+        crc ^= (data[byteCtr]);
+        for ( bit = 8; bit > 0; --bit)
+        {
+            if (crc & 0x80) crc = (crc << 1) ^ POLYNOMIAL;
+            else crc = (crc << 1);
+        }
+    }
+    if (crc != checksum) return 1;
+    else return 0;
+}
+*/
diff --git a/source/shoh/src/threads/temperature/SensorTempSHT20.h b/source/shoh/src/threads/temperature/SensorTempSHT20.h
new file mode 100644
index 0000000..021e1a5
--- /dev/null
+++ b/source/shoh/src/threads/temperature/SensorTempSHT20.h
@@ -0,0 +1,28 @@
+/*
+ * SensorTempSHT20.h
+ *
+ *  Created on: 16 May 2023
+ */
+
+#ifndef THREADS_TEMPERATURE_SENSORTEMPTC74_H_
+#define THREADS_TEMPERATURE_SENSORTEMPTC74_H_
+
+#include "I2C.h"
+#include "chip.h"
+
+class SensorTempSHT20 {
+public:
+	SensorTempSHT20(I2C* pi2c);
+	virtual ~SensorTempSHT20();
+private:
+	uint16_t read();
+
+	bool write_com(uint8_t com, uint8_t *trdata, const uint16_t size);
+	bool read_com(uint8_t com, uint8_t *rdata, uint16_t size);
+
+	I2C* _pi2c;
+	const uint8_t _dev_addr;
+	bool _up_flag;
+};
+
+#endif /* THREADS_TEMPERATURE_SENSORTEMPSHT20_H_ */