[mcp3204] differential mode support (#7436)

Co-authored-by: marko <marko@>
Co-authored-by: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>

esphome/components/mcp3204/mcp3204.cpp

@@ -16,16 +16,21 @@ void MCP3204::dump_config() {
   ESP_LOGCONFIG(TAG, "  Reference Voltage: %.2fV", this->reference_voltage_);
 }
 
-float MCP3204::read_data(uint8_t pin) {
+float MCP3204::read_data(uint8_t pin, bool differential) {
-  uint8_t adc_primary_config = 0b00000110 | (pin >> 2);
+  uint8_t command, b0, b1;
-  uint8_t adc_secondary_config = pin << 6;
+
+  command = (1 << 6) |                       // start bit
+            ((differential ? 0 : 1) << 5) |  // single or differential bit
+            ((pin & 0x07) << 2);             // pin
+
   this->enable();
-  this->transfer_byte(adc_primary_config);
+  this->transfer_byte(command);
-  uint8_t adc_primary_byte = this->transfer_byte(adc_secondary_config);
+  b0 = this->transfer_byte(0x00);
-  uint8_t adc_secondary_byte = this->transfer_byte(0x00);
+  b1 = this->transfer_byte(0x00);
   this->disable();
-  uint16_t digital_value = (adc_primary_byte << 8 | adc_secondary_byte) & 0b111111111111;
+
-  return float(digital_value) / 4096.000 * this->reference_voltage_;
+  uint16_t digital_value = encode_uint16(b0, b1) >> 4;
+  return float(digital_value) / 4096.000 * this->reference_voltage_;  // in V
 }
 
 }  // namespace mcp3204

esphome/components/mcp3204/mcp3204.h

@@ -18,7 +18,7 @@ class MCP3204 : public Component,
   void setup() override;
   void dump_config() override;
   float get_setup_priority() const override;
-  float read_data(uint8_t pin);
+  float read_data(uint8_t pin, bool differential);
 
  protected:
   float reference_voltage_;

esphome/components/mcp3204/sensor/__init__.py

@@ -13,6 +13,7 @@ MCP3204Sensor = mcp3204_ns.class_(
     "MCP3204Sensor", sensor.Sensor, cg.PollingComponent, voltage_sampler.VoltageSampler
 )
 CONF_MCP3204_ID = "mcp3204_id"
+CONF_DIFF_MODE = "diff_mode"
 
 CONFIG_SCHEMA = (
     sensor.sensor_schema(MCP3204Sensor)
@@ -20,6 +21,7 @@ CONFIG_SCHEMA = (
         {
             cv.GenerateID(CONF_MCP3204_ID): cv.use_id(MCP3204),
             cv.Required(CONF_NUMBER): cv.int_range(min=0, max=7),
+            cv.Optional(CONF_DIFF_MODE, default=False): cv.boolean,
         }
     )
     .extend(cv.polling_component_schema("60s"))
@@ -30,6 +32,7 @@ async def to_code(config):
     var = cg.new_Pvariable(
         config[CONF_ID],
         config[CONF_NUMBER],
+        config[CONF_DIFF_MODE],
     )
     await cg.register_parented(var, config[CONF_MCP3204_ID])
     await cg.register_component(var, config)

esphome/components/mcp3204/sensor/mcp3204_sensor.cpp

@@ -7,16 +7,15 @@ namespace mcp3204 {
 
 static const char *const TAG = "mcp3204.sensor";
 
-MCP3204Sensor::MCP3204Sensor(uint8_t pin) : pin_(pin) {}
-
 float MCP3204Sensor::get_setup_priority() const { return setup_priority::DATA; }
 
 void MCP3204Sensor::dump_config() {
   LOG_SENSOR("", "MCP3204 Sensor", this);
   ESP_LOGCONFIG(TAG, "  Pin: %u", this->pin_);
+  ESP_LOGCONFIG(TAG, "  Differential Mode: %s", YESNO(this->differential_mode_));
   LOG_UPDATE_INTERVAL(this);
 }
-float MCP3204Sensor::sample() { return this->parent_->read_data(this->pin_); }
+float MCP3204Sensor::sample() { return this->parent_->read_data(this->pin_, this->differential_mode_); }
 void MCP3204Sensor::update() { this->publish_state(this->sample()); }
 
 }  // namespace mcp3204

esphome/components/mcp3204/sensor/mcp3204_sensor.h

@@ -15,7 +15,7 @@ class MCP3204Sensor : public PollingComponent,
                       public sensor::Sensor,
                       public voltage_sampler::VoltageSampler {
  public:
-  MCP3204Sensor(uint8_t pin);
+  MCP3204Sensor(uint8_t pin, bool differential_mode) : pin_(pin), differential_mode_(differential_mode) {}
 
   void update() override;
   void dump_config() override;
@@ -24,6 +24,7 @@ class MCP3204Sensor : public PollingComponent,
 
  protected:
   uint8_t pin_;
+  bool differential_mode_;
 };
 
 }  // namespace mcp3204

tests/components/mcp3204/common.yaml

@@ -4,7 +4,21 @@ mcp3204:
 
 sensor:
   - platform: mcp3204
-    id: mcp3204_sensor
+    id: mcp3204_default_single_0
     mcp3204_id: mcp3204_hub
     number: 0
     update_interval: 5s
+
+  - platform: mcp3204
+    id: mcp3204_single_0
+    mcp3204_id: mcp3204_hub
+    number: 0
+    diff_mode: false
+    update_interval: 5s
+
+  - platform: mcp3204
+    id: mcp3204_diff_0_1
+    mcp3204_id: mcp3204_hub
+    number: 0
+    diff_mode: true
+    update_interval: 5s