bit bang the "i2c" protocol

components/sm2235/README.md

@@ -1,11 +1,11 @@
 # SM2235 LED driver
 
-Requires a configured i2c bus
-
 Example:
 ```yaml
 sm2235:
   - id: my_sm        #optional
+    sda: 4
+    scl: 5
     rgb_current: 12  #optional
     cw_current: 25   #optional
 

components/sm2235/__init__.py

@@ -1,13 +1,12 @@
 import esphome.codegen as cg
 import esphome.config_validation as cv
-from esphome.components import i2c
-from esphome.const import CONF_ID, CONF_NUM_CHANNELS
+from esphome import pins
+from esphome.const import CONF_ID, CONF_NUM_CHANNELS, CONF_SCL, CONF_SDA
 
-DEPENDENCIES = ["i2c"]
 MULTI_CONF = True
 
 sm2235_ns = cg.esphome_ns.namespace("sm2235")
-SM2235 = sm2235_ns.class_("SM2235", cg.Component, i2c.I2CDevice)
+SM2235 = sm2235_ns.class_("SM2235", cg.Component)
 
 CONF_RGB_CURRENT = "rgb_current"
 CONF_CW_CURRENT = "cw_current"
@@ -16,19 +15,23 @@ CONFIG_SCHEMA = (
     cv.Schema(
         {
             cv.GenerateID(): cv.declare_id(SM2235),
+            cv.Required(CONF_SDA): pins.internal_gpio_input_pin_schema,
+            cv.Required(CONF_SCL): pins.internal_gpio_input_pin_schema,
             cv.Optional(CONF_RGB_CURRENT, default=12): cv.int_range(min=4, max=64),
             cv.Optional(CONF_CW_CURRENT, default=25): cv.int_range(min=5, max=80),
         }
     )
     .extend(cv.COMPONENT_SCHEMA)
-    .extend(i2c.i2c_device_schema(0))
 )
 
 
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(var, config)
-    await i2c.register_i2c_device(var, config)
 
+    pin = await cg.gpio_pin_expression(config[CONF_SDA])
+    cg.add(var.set_sda_pin(pin))
+    pin = await cg.gpio_pin_expression(config[CONF_SCL])
+    cg.add(var.set_scl_pin(pin))
     currents = round((config[CONF_RGB_CURRENT] - 4) / 4) * 16 + round((config[CONF_CW_CURRENT] - 5) / 5)
     cg.add(var.set_currents(currents))

components/sm2235/sm2235.cpp

@@ -1,18 +1,44 @@
 #include "sm2235.h"
 #include "esphome/core/log.h"
 #include "esphome/core/helpers.h"
-#include "esphome/core/hal.h"
 
 namespace esphome {
 namespace sm2235 {
 
 static const char *const TAG = "sm2235";
 
+void SM2235::setup() {
+  this->sda_pin_->setup();
+  this->scl_pin_->setup();
+  this->scl_pin_->digital_write(true);
+  this->sda_pin_->digital_write(true);
+}
+
 void SM2235::dump_config() {
   ESP_LOGCONFIG(TAG, "SM2235:");
   ESP_LOGCONFIG(TAG, "  Channels: %d", this->num_channels_);
 }
 
+void SM2235::start_() {
+  this->sda_pin_->digital_write(false);
+  delayMicroseconds(4);
+}
+
+void SM2235::stop_() {
+  this->sda_pin_->digital_write(true);
+  delayMicroseconds(2);
+}
+
+void SM2235::send_byte_(uint8_t value) {
+  for (int i = 0; i < 9; i++, value <<= 1) {
+    this->scl_pin_->digital_write(false);
+    this->sda_pin_->digital_write(value & 0x80 > 0);
+    delayMicroseconds(2);
+    this->scl_pin_->digital_write(true);
+    delayMicroseconds(2);
+  }
+}
+
 void SM2235::update_(uint8_t channel) {
   uint8_t byte0 = 0xc0 + channel;
   switch(this->num_channels_) {
@@ -27,12 +53,13 @@ void SM2235::update_(uint8_t channel) {
    case 5:
     byte0 |= 0x30; break;
   }
-  uint8_t data[3];
-  data[0] = this->currents_;
+  this->start_();
+  this->send_byte_(byte0);
+  this->send_byte_(this->currents_);
   uint16_t value = this->values_[channel]; 
-  data[1] = value >> 8;
-  data[2] = value & 0xff;
-  this->bus_->write(byte0, data, 3);
+  this->send_byte_(value >> 8);
+  this->send_byte_(value & 0xff);
+  this->stop_();
 }
 
 void SM2235::register_channel(SM2235Channel *channel, uint8_t num) {

components/sm2235/sm2235.h

@@ -1,8 +1,8 @@
 #pragma once
 
 #include "esphome/core/component.h"
+#include "esphome/core/hal.h"
 #include "esphome/components/output/float_output.h"
-#include "esphome/components/i2c/i2c.h"
 
 namespace esphome {
 namespace sm2235 {
@@ -21,10 +21,13 @@ class SM2235Channel : public output::FloatOutput {
   SM2235 *parent_;
 };
 
-class SM2235 : public Component, public i2c::I2CDevice {
+class SM2235 : public Component {
  public:
+  void setup() override;
   void dump_config() override;
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
+  void set_sda_pin(InternalGPIOPin *pin) { this->sda_pin_ = pin; }
+  void set_scl_pin(InternalGPIOPin *pin) { this->scl_pin_ = pin; }
 
   void register_channel(SM2235Channel *channel, uint8_t num);
   void set_currents(uint8_t currents) { this->currents_ = currents; }
@@ -35,7 +38,12 @@ class SM2235 : public Component, public i2c::I2CDevice {
   uint8_t currents_;
   uint8_t num_channels_{0};
   uint16_t values_[5] = {0};
+  InternalGPIOPin *sda_pin_;
+  InternalGPIOPin *scl_pin_;
 
+  void start_();
+  void stop_();
+  void send_byte_(uint8_t value);
   void update_(uint8_t channel);
 };