[components] Use sign_extend for raw sensor readings (#20934)

esphome/components/ade7880/ade7880_i2c.cpp

@@ -11,12 +11,6 @@
 
 namespace esphome::ade7880 {
 
-// adapted from https://stackoverflow.com/a/55912127/1886371
-template<size_t Bits, typename T> inline T sign_extend(const T &v) noexcept {
-  using S = struct { signed Val : Bits; };
-  return reinterpret_cast<const S *>(&v)->Val;
-}
-
 // Register types
 // unsigned 8-bit (uint8_t)
 // signed 10-bit - 16-bit ZP on wire (int16_t, needs sign extension)
@@ -49,7 +43,7 @@ uint16_t ADE7880::read_u16_register16_(uint16_t a_register) {
 
 int32_t ADE7880::read_s24zp_register16_(uint16_t a_register) {
   // s24zp means 24 bit signed value in the lower 24 bits of a 32-bit register
-  int32_t in;
+  uint32_t in;
   this->read_register16(a_register, reinterpret_cast<uint8_t *>(&in), sizeof(in));
   return sign_extend<24>(convert_big_endian(in));
 }

esphome/components/bme280_base/bme280_base.cpp

@@ -3,6 +3,7 @@
 
 #include "bme280_base.h"
 #include "esphome/core/hal.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include <esphome/components/sensor/sensor.h>
 #include <esphome/core/component.h>
@@ -144,11 +145,10 @@ void BME280Component::setup() {
   this->calibration_.h1 = read_u8_(BME280_REGISTER_DIG_H1);
   this->calibration_.h2 = read_s16_le_(BME280_REGISTER_DIG_H2);
   this->calibration_.h3 = read_u8_(BME280_REGISTER_DIG_H3);
-  // h4 and h5 are signed 12-bit values; shift left then arithmetic right shift to sign-extend
-  int16_t h4_raw = read_u8_(BME280_REGISTER_DIG_H4) << 4 | (read_u8_(BME280_REGISTER_DIG_H4 + 1) & 0x0F);
-  this->calibration_.h4 = static_cast<int16_t>(h4_raw << 4) >> 4;
-  int16_t h5_raw = read_u8_(BME280_REGISTER_DIG_H5 + 1) << 4 | (read_u8_(BME280_REGISTER_DIG_H5) >> 4);
-  this->calibration_.h5 = static_cast<int16_t>(h5_raw << 4) >> 4;
+  this->calibration_.h4 =
+      sign_extend<12>(read_u8_(BME280_REGISTER_DIG_H4) << 4 | (read_u8_(BME280_REGISTER_DIG_H4 + 1) & 0x0F));
+  this->calibration_.h5 =
+      sign_extend<12>(read_u8_(BME280_REGISTER_DIG_H5 + 1) << 4 | (read_u8_(BME280_REGISTER_DIG_H5) >> 4));
   this->calibration_.h6 = read_u8_(BME280_REGISTER_DIG_H6);
 
   uint8_t humid_control_val = 0;

esphome/components/cs5460a/cs5460a.cpp

@@ -1,4 +1,5 @@
 #include "cs5460a.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 namespace esphome::cs5460a {
@@ -304,7 +305,7 @@ bool CS5460AComponent::check_status_() {
       voltage_sensor_->publish_state(raw_voltage * voltage_multiplier_);
 
     if (power_sensor_ != nullptr && raw_energy != prev_raw_energy_) {
-      int32_t raw = (int32_t) (raw_energy << 8) >> 8; /* Sign-extend */
+      int32_t raw = sign_extend<24>(raw_energy);
       power_sensor_->publish_state(raw * power_multiplier_);
       prev_raw_energy_ = raw_energy;
     }

esphome/components/hx711/hx711.cpp

@@ -67,9 +67,7 @@ bool HX711Sensor::read_sensor_(uint32_t *result) {
 
   this->status_clear_warning();
 
-  if (data & 0x800000ULL) {
-    data |= 0xFF000000ULL;
-  }
+  data = static_cast<uint32_t>(sign_extend<24>(data));
 
   if (result != nullptr)
     *result = data;

esphome/components/max31856/max31856.cpp

@@ -1,5 +1,6 @@
 #include "max31856.h"
 
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include <cmath>
 
@@ -53,12 +54,8 @@ void MAX31856Sensor::read_thermocouple_temperature_() {
     // Faults have been logged, clear it for next loop
     this->clear_fault_();
   } else {
-    int32_t temp24 = this->read_register24_(MAX31856_LTCBH_REG);
-    if (temp24 & 0x800000) {
-      temp24 |= 0xFF000000;  // fix sign
-    }
-
-    temp24 >>= 5;  // bottom 5 bits are unused
+    // bottom 5 bits are unused
+    const int32_t temp24 = sign_extend<24>(this->read_register24_(MAX31856_LTCBH_REG)) >> 5;
 
     float temp_c = temp24;
     temp_c *= 0.0078125;

esphome/components/max9611/max9611.cpp

@@ -1,17 +1,10 @@
 #include "max9611.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include "esphome/components/i2c/i2c_bus.h"
 
 namespace esphome::max9611 {
 using namespace esphome::i2c;
-// Sign extend
-// http://graphics.stanford.edu/~seander/bithacks.html#FixedSignExtend
-template<typename T, unsigned B> inline T signextend(const T x) {
-  struct {
-    T x : B;
-  } s;
-  return s.x = x;
-}
 // Map the gain register to in uV/LSB
 float gain_to_lsb(MAX9611Multiplexer gain) {
   float lsb = 0.0;
@@ -72,7 +65,7 @@ void MAX9611Component::update() {
   uint16_t t_register = ((register_map_[TEMP_DATA_BYTE_MSB_ADRR] << 8) | (register_map_[TEMP_DATA_BYTE_LSB_ADRR])) >> 7;
   float voltage = rs_register * VOUT_LSB;
   float shunt_voltage = (csa_register * gain_to_lsb(gain_)) / MICRO_VOLTS_PER_VOLT;
-  float temp = signextend<signed int, 9>(t_register) * TEMP_LSB;
+  float temp = sign_extend<9>(t_register) * TEMP_LSB;
   float amps = shunt_voltage / current_resistor_;
   float watts = amps * voltage;
 

esphome/components/xdb401/xdb401.cpp

@@ -127,8 +127,7 @@ i2c::ErrorCode XDB401Component::read_pressure_(float &pressure) {
   format_hex_pretty_to(pressure_buf, sizeof(pressure_buf), p_data, 3);
   ESP_LOGV(TAG, "Got pressure data: %s", pressure_buf);
 
-  // Sign-extend 24-bit big-endian pressure value to int32_t.
-  int32_t raw_pressure = static_cast<int32_t>(encode_uint24(p_data[0], p_data[1], p_data[2]) << 8) >> 8;
+  int32_t raw_pressure = sign_extend<24>(encode_uint24(p_data[0], p_data[1], p_data[2]));
   ESP_LOGD(TAG, "Pressure data raw %" PRId32, raw_pressure);
 
   pressure = (static_cast<float>(raw_pressure) / CONVERT_PRESSURE) *

esphome/components/xgzp68xx/xgzp68xx.cpp

@@ -76,9 +76,7 @@ void XGZP68XXComponent::update() {
     ESP_LOGV(TAG, "Got raw pressure=%" PRIu32 ", raw temperature=%u, K value=%u", pressure_raw, temperature_raw,
              this->k_value_);
 
-    // Sign extend the pressure
-    float pressure_in_pa = (float) (((int32_t) pressure_raw << 8) >> 8);
-    pressure_in_pa /= (float) (this->k_value_);
+    const float pressure_in_pa = static_cast<float>(sign_extend<24>(pressure_raw)) / this->k_value_;
 
     float temperature = ((float) (int16_t) temperature_raw) / 256.0f;