simplest_barometer

# Example for a simple barometer on an LCD

An example to demonstrate how to use `HD44780`, `BMP280`, and `PCF8574`.

## What it does

The example configures `BMP280` and `HD44780` via `PCF8574`. It shows
temperature and pressure on the LCD in a loop.

## Wiring

Connect `HD44780` and `PCF8574`.

| `HD44780` | `PCF8574` |
|-----------|-----------|
| `RS`      | 0         |
| `E`       | 2         |
| `D4`      | 4         |
| `D5`      | 5         |
| `D6`      | 6         |
| `D7`      | 7         |
| `BL`      | 3         |

Connect all `SCL` and `SDA` pins on `PCF8574` and `BMP280` to the following
pins with appropriate pull-up resistors.

| Name | Description | Defaults |
|------|-------------|----------|
| `CONFIG_EXAMPLE_I2C_MASTER_SCL` | GPIO number for `SCL` | "5" for `esp8266`, "6" for `esp32c3`, "19" for `esp32`, `esp32s2`, and `esp32s3` |
| `CONFIG_EXAMPLE_I2C_MASTER_SDA` | GPIO number for `SDA` | "4" for `esp8266`, "5" for `esp32c3`, "18" for `esp32`, `esp32s2`, and `esp32s3` |