Will Apache #NuttX OS talk I2C with Bosch BME280 Sensor? (Temperature + Humidity + Air Pressure) ... Let's find out!

https://github.com/lupyuen/bme280-nuttx

Verify with Bus Pirate that our BME280 works OK ... Despite my horrid soldering 😂

https://github.com/lupyuen/bme280-nuttx#test-with-bus-pirate

Connect BME280 to #RISCV PineCone #BL602 @PINE64 ... Preferably not on a cooking pot 😂

https://github.com/lupyuen/bme280-nuttx#connect-bme280

Enable the I2C Port and I2C Character Driver on Apache #NuttX OS ... So it will talk with BME280

https://github.com/lupyuen/bme280-nuttx#configure-nuttx

Apache #NuttX OS doesn't have a BME280 Driver ... Let's test the BMP280 Driver instead (Air Pressure only)

https://github.com/lupyuen/bme280-nuttx#configure-nuttx

We patch the I2C Address and Device ID in the #NuttX BMP280 Driver ... So it will work with BME280

https://github.com/lupyuen/bme280-nuttx#change-i2c-address-and-device-id

Here's how we register the BMP280 Driver at #NuttX Startup

https://github.com/lupyuen/bme280-nuttx#register-bmp280-driver

#NuttX BMP280 Driver fails because the detected Device ID is 0 ... Let's find out why 🤔

https://github.com/lupyuen/bme280-nuttx#invalid-device-id

Logic Analyser shows that #BL602 sent the wrong Register ID to BME280 ... Let's fix this 🤔

https://github.com/lupyuen/bme280-nuttx#invalid-register-id

Here's how we connected our Logic Analyser to PineCone #BL602 ... For testing the #NuttX BMP280 Driver

https://github.com/lupyuen/bme280-nuttx/blob/main/README.md#invalid-register-id

#BL602 #NuttX I2C Driver doesn't log the data transferred ... Let's log ourselves

https://github.com/lupyuen/bme280-nuttx#log-i2c-transfers

#BL602 has a peculiar I2C Port ... We need to send the I2C Sub Address (Register ID) separately from the I2C Data ... This might cause the BMP280 Driver to fail

https://github.com/lupyuen/bme280-nuttx#set-i2c-sub-address

#BL602 #NuttX I2C Driver expects us to provide the I2C Sub Address ... Let's patch the BMP280 Driver to pass the Register ID as I2C Sub Address

https://github.com/lupyuen/bme280-nuttx#set-i2c-sub-address

Here's how we patch the #NuttX BMP280 Driver to send the Register ID as I2C Sub Address (instead of I2C Data)

https://github.com/lupyuen/bme280-nuttx#set-i2c-sub-address

#NuttX BMP280 Driver loads OK on #BL602 ... After setting the Register ID as I2C Sub Address! 🎉

https://github.com/lupyuen/bme280-nuttx#bmp280-driver-loads-ok

#NuttX BMP280 Driver appears as "/dev/sensor/baro0" ... Let's read the device

https://github.com/lupyuen/bme280-nuttx#bmp280-driver-loads-ok

We enable the #NuttX Sensor Test App ... To test the BMP280 Driver

https://github.com/lupyuen/bme280-nuttx#run-sensor-test-app

#NuttX BMP280 Driver says it's 29 °C with air pressure 1,006 millibars ... Yep looks right for Sunny Singapore by the Seaside 👍

https://github.com/lupyuen/bme280-nuttx#run-sensor-test-app

#NuttX BMP280 Driver works OK with our BME280 Sensor ... But we're missing one thing: Humidity ... Can we port the BME280 Driver from Zephyr OS? 🤔

https://github.com/lupyuen/bme280-nuttx#port-bme280-driver-from-zephyr-os

Zephyr BME280 Driver looks similar to #NuttX BMP280 Driver ... So porting Zephyr BME280 Driver to NuttX might not be so hard 🤔

https://github.com/lupyuen/bme280-nuttx#port-bme280-driver-from-zephyr-os

Zephyr BME280 Driver builds OK on #NuttX (with a few tweaks) 🎉 ... Now we wrap the Zephyr Driver as a NuttX Driver

https://github.com/lupyuen/bme280-nuttx#wrap-zephyr-driver-as-nuttx-driver

Our #NuttX Driver Wrapper wraps around the Zephyr BME280 Driver ... So it works like a NuttX Driver

https://github.com/lupyuen/bme280-nuttx#wrap-zephyr-driver-as-nuttx-driver

Our #NuttX BME280 Driver reads the Sensor Data from Zephyr Driver in two steps: 1️⃣ Fetch the sensor sample 2️⃣ Get the channel data

https://github.com/lupyuen/bme280-nuttx#read-sensor-data-from-zephyr-driver

Power Management works a little differently in #NuttX vs Zephyr ... Here's how our NuttX BME280 Driver calls the Zephyr Driver to do Power Management

https://github.com/lupyuen/bme280-nuttx#power-management

BME280 Standby Duration is static in Zephyr but configured at runtime in #NuttX ... So we set it in our NuttX BME280 Driver

https://github.com/lupyuen/bme280-nuttx#standby-duration

Zephyr BME280 Driver ported to Apache #NuttX OS ... Works great on NuttX! 🎉

https://github.com/lupyuen/bme280-nuttx#output-log

We made minimal changes to Zephyr BME280 Driver while porting to #NuttX OS

https://github.com/lupyuen/bme280-nuttx#zephyr-driver-modified-for-nuttx

#NuttX doesn't have a Sensor Type that supports BME280 Temperature + Humidity + Pressure ... So our NuttX BME280 Driver combines 2 Sensor Types: 1️⃣ Barometer Sensor (Pressure + Temperature) 2️⃣ Humidity Sensor

https://github.com/lupyuen/bme280-nuttx#combined-barometer-and-humidity-sensor

Each #NuttX Sensor defines its operations for 1️⃣ Activating the sensor 2️⃣ Fetching sensor data 3️⃣ Setting the standby interval

https://github.com/lupyuen/bme280-nuttx#combined-barometer-and-humidity-sensor

At #NuttX Startup we register both BME280 sensors: Barometer Sensor and Humidity Sensor

https://github.com/lupyuen/bme280-nuttx#combined-barometer-and-humidity-sensor