1 files changed, 40 insertions, 0 deletions
diff --git a/src/driver/scd4x.cc b/src/driver/scd4x.cc
new file mode 100644
index 0000000..c0901e8
--- /dev/null
+++ b/src/driver/scd4x.cc
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2021 Daniel Friesel
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+#include "driver/scd4x.h"
+#include "driver/gpio.h"
+#if defined(MULTIPASS_ARCH_HAS_I2C) && !defined(DRIVER_SOFTI2C)
+#include "driver/i2c.h"
+#else
+#include "driver/soft_i2c.h"
+#endif
+
+void SCD4x::start()
+{
+	txbuf[0] = 0x21;
+	txbuf[1] = 0xb1;
+	i2c.xmit(address, 2, txbuf, 0, rxbuf);
+}
+
+void SCD4x::stop()
+{
+	txbuf[0] = 0x3f;
+	txbuf[1] = 0x86;
+	i2c.xmit(address, 2, txbuf, 0, rxbuf);
+}
+
+void SCD4x::read()
+{
+	txbuf[0] = 0xec;
+	txbuf[1] = 0x05;
+
+	if (i2c.xmit(address, 1, txbuf, 9, rxbuf) == 0) {
+		co2 = (rxbuf[0] << 8) + rxbuf[1];
+		rawTemperature = ((rxbuf[3] << 8) + rxbuf[4]);
+		rawHumidity = (rxbuf[6] << 8) + rxbuf[7];
+	}
+}
+
+SCD4x scd4x;