1 files changed, 92 insertions, 0 deletions
diff --git a/src/drivers/touchwheel.cpp b/src/drivers/touchwheel.cpp
new file mode 100644
index 00000000..11a115fb
--- /dev/null
+++ b/src/drivers/touchwheel.cpp
@@ -0,0 +1,92 @@
+#include "touchwheel.hpp"
+
+#include <cstdint>
+
+#include "assert.h"
+#include "driver/i2c.h"
+#include "esp_err.h"
+#include "esp_log.h"
+#include "hal/i2c_types.h"
+
+#include "i2c.hpp"
+
+namespace drivers {
+
+static const char* kTag = "TOUCHWHEEL";
+static const uint8_t kTouchWheelAddress = 0x1C;
+
+static const uint8_t kWriteMask = 0x80;
+static const uint8_t kReadMask = 0xA0;
+
+double normalise(uint16_t min, uint16_t max, uint16_t value) {
+  if (value >= max) {
+    return 1.0;
+  }
+  if (value <= min) {
+    return 0.0;
+  }
+  uint16_t range = max - min;
+  return (double)(value - min) / range;
+}
+
+
+auto TouchWheel::create(GpioExpander* expander)
+    -> cpp::result<std::unique_ptr<TouchWheel>, Error> {
+  std::unique_ptr<TouchWheel> wheel = std::make_unique<TouchWheel>(expander);
+  wheel->WriteRegister(Register::SLIDER_OPTIONS, 0xC0);
+  return wheel;
+}
+
+TouchWheel::TouchWheel(GpioExpander* gpio) {
+  this->gpio_ = gpio;
+};
+
+TouchWheel::~TouchWheel(){
+};
+
+void TouchWheel::WriteRegister(uint8_t reg, uint8_t val) {
+  // uint8_t maskedReg = reg | kWriteMask;
+  uint8_t maskedReg = reg;
+  I2CTransaction transaction;
+  transaction.start()
+      .write_addr(kTouchWheelAddress, I2C_MASTER_WRITE)
+      .write_ack(maskedReg, val)
+      .stop();
+  ESP_ERROR_CHECK(transaction.Execute());
+}
+
+void TouchWheel::ReadRegister(uint8_t reg, uint8_t* data, uint8_t count) {
+  // uint8_t maskedReg = reg | kReadMask;
+  uint8_t maskedReg = reg;
+
+  if (count <= 0) {
+    return;
+  }
+
+  I2CTransaction transaction;
+  transaction.start()
+      .write_addr(kTouchWheelAddress, I2C_MASTER_WRITE)
+      .write_ack(maskedReg)
+      .stop()
+      .start()
+      .write_addr(kTouchWheelAddress, I2C_MASTER_READ)
+      .read(data, I2C_MASTER_NACK)
+      .stop();
+
+  // TODO: Handle errors here.
+  ESP_ERROR_CHECK(transaction.Execute());
+}
+
+void TouchWheel::Update() {
+    // Read data from device into member struct
+    uint8_t position;
+    this->ReadRegister(Register::SLIDER_POSITION, &position, 1);
+    data_.wheel_position = position;
+}
+
+TouchWheelData TouchWheel::GetTouchWheelData() const {
+  return data_;
+}
+
+
+}  // namespace drivers