From cf97c18554b9aa88202b9d2463ee08cafd1252b0 Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Sun, 14 Feb 2021 21:42:26 +0100
Subject: add initialization and readout to CCS811 driver

---
 include/driver/ccs811.h   | 24 ++++++++++++----
 src/app/i2cdetect/main.cc | 18 +++++++++++-
 src/driver/ccs811.cc      | 72 ++++++++++++++++++++++++++++++++++++++++++-----
 3 files changed, 101 insertions(+), 13 deletions(-)

diff --git a/include/driver/ccs811.h b/include/driver/ccs811.h
index aab1e35..8be0e6e 100644
--- a/include/driver/ccs811.h
+++ b/include/driver/ccs811.h
@@ -9,15 +9,29 @@
 class CCS811 {
 	private:
 		CCS811(const CCS811 &copy);
-		unsigned char const address;
-		unsigned char txbuf[3];
-		unsigned char rxbuf[2];
+		unsigned char const address = 0x5a;
+		unsigned char txbuf[5];
+		unsigned char rxbuf[8];
 
 	public:
-		CCS811(unsigned char const addr) : address(addr) {}
+		CCS811() {}
+
+		unsigned short eco2;
+		unsigned short tvoc;
+		unsigned char status;
+		unsigned char error_id;
+		unsigned char raw_current;
+		unsigned short raw_voltage;
 
 		void init();
-		short check();
+		unsigned char getStatus();
+		unsigned char getError();
+		unsigned char getManufacturerID();
+		void startFirmware();
+		void setMode(unsigned char mode);
+		void read();
+		void setEnv(unsigned char humi, unsigned char humi_fraction, unsigned char temp, unsigned char temp_fraction);
+		void reset();
 };
 
 extern CCS811 ccs811;
diff --git a/src/app/i2cdetect/main.cc b/src/app/i2cdetect/main.cc
index 4d6ebe9..92c812c 100644
--- a/src/app/i2cdetect/main.cc
+++ b/src/app/i2cdetect/main.cc
@@ -125,7 +125,13 @@ void loop(void)
 	kout << "BME680 gas resistance " << data.gas_resistance << endl;
 #endif
 #ifdef DRIVER_CCS811
-	kout << "CCS811 status is " << ccs811.check() << endl;
+	ccs811.read();
+	kout << "CCS811 eCO₂ : " << ccs811.eco2 << " ppm" << endl;
+	kout << "CCS811 tVOC : " << ccs811.tvoc << " ppb" << endl;
+	kout << bin;
+	kout << "CCS811 status: " << ccs811.status << endl;
+	kout << "CCS811 error: " << ccs811.error_id << endl;
+	kout << dec;
 #endif
 #ifdef DRIVER_HDC1080
 	/*
@@ -186,7 +192,17 @@ int main(void)
 	kout << "I2C setup OK" << endl;
 
 #ifdef DRIVER_CCS811
+	kout << hex;
+	kout << "CCS811 HWID: " << ccs811.getManufacturerID() << endl;
+	arch.delay_ms(65);
+	kout << "CCS811 status: " << ccs811.getStatus() << endl;
+	arch.delay_ms(65);
 	ccs811.init();
+	arch.delay_ms(65);
+	kout << "CCS811 status: " << ccs811.getStatus() << endl;
+	kout << dec;
+	ccs811.setMode(1);
+	//arch.delay_ms(50);
 #endif
 #ifdef DRIVER_HDC1080
 	hdc1080.init();
diff --git a/src/driver/ccs811.cc b/src/driver/ccs811.cc
index ad0eabc..8c16b8a 100644
--- a/src/driver/ccs811.cc
+++ b/src/driver/ccs811.cc
@@ -17,18 +17,76 @@
 
 void CCS811::init()
 {
-	gpio.output(nWAKE);
-	gpio.write(nWAKE, 1);
+	startFirmware();
+	//setMode(1);
+	//setEnv(50, 0, 0, 0);
 }
 
-short CCS811::check()
+// switch to Application mode
+void CCS811::startFirmware()
+{
+	if (getStatus() & 0x10) {
+		txbuf[0] = 0xf4;
+		i2c.xmit(address, 1, txbuf, 0, rxbuf);
+	}
+}
+
+unsigned char CCS811::getManufacturerID()
 {
-	gpio.write(nWAKE, 0);
 	txbuf[0] = 0x20;
-	rxbuf[0] = 0;
 	i2c.xmit(address, 1, txbuf, 1, rxbuf);
-	gpio.write(nWAKE, 1);
 	return rxbuf[0];
 }
 
-CCS811 ccs811(0x5a);
+void CCS811::setMode(unsigned char mode)
+{
+	txbuf[0] = 0x01;
+	txbuf[1] = (mode & 0x07) << 4;
+	i2c.xmit(address, 2, txbuf, 0, rxbuf);
+}
+
+void CCS811::read()
+{
+	txbuf[0] = 0x02;
+	i2c.xmit(address, 1, txbuf, 8, rxbuf);
+	eco2 = (rxbuf[0] << 8) + rxbuf[1];
+	tvoc = (rxbuf[2] << 8) + rxbuf[3];
+	status = rxbuf[4];
+	error_id = rxbuf[5];
+}
+
+void CCS811::setEnv(unsigned char humi, unsigned char humi_fraction, unsigned char temp, unsigned char temp_fraction)
+{
+	txbuf[0] = 0x05;
+	txbuf[1] = humi;
+	txbuf[2] = humi_fraction;
+	txbuf[3] = temp; //((temp - 25) << 1) + (((temp - 25) & 0x80) >> 7);
+	txbuf[4] = temp_fraction; //(temp << 1) + ((temp & 0x80) >> 7);
+	i2c.xmit(address, 5, txbuf, 0, rxbuf);
+}
+
+unsigned char CCS811::getStatus()
+{
+	txbuf[0] = 0x00;
+	i2c.xmit(address, 1, txbuf, 1, rxbuf);
+	return rxbuf[0];
+}
+
+unsigned char CCS811::getError()
+{
+	txbuf[0] = 0xe0;
+	i2c.xmit(address, 1, txbuf, 1, rxbuf);
+	return rxbuf[0];
+}
+
+// switch to Bootloader mode
+void CCS811::reset()
+{
+	txbuf[0] = 0xff;
+	txbuf[1] = 0x11;
+	txbuf[2] = 0xe5;
+	txbuf[3] = 0x72;
+	txbuf[4] = 0x8a;
+}
+
+CCS811 ccs811;
-- 
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