Petfeeder Sensor

This project is part of a larger smart home effort working with Home Assistant. I feel like there should be a better way to document all the subproject in one place, so that might still come.

Complete DIY was also an option, as done by jplanaux's 3D printed cat feeder or many others on Thingiverse. Plenty other can be found on instructables.com. I don't have a 3D printer (yet), and I had the idea that modding a 2nd hand pet feeder would be easier to achieve (as well as everything being food grade material).

Table of Contents

1. MQTT communication
2. ESP8266 toolchain SDK installation
3. CLion Instructions
4. WiFi and MQTT configuration with SDKCONFIG

MQTT communication

Motor to next position, send to topic /petfeeder/calibrate/tick (arbitrary payload, may be empty).
Request raw scale value, send to topic /petfeeder/calibrate/raw/req (arbitrary payload, may be empty).
Result of raw scale request can be read from topic /petfeeder/calibrate/raw/resp

General about the code

It seems MQTT publish can not be called too frequently, crashes on 2 sec interval, seems fine on 5 sec. Alternative is to gather more readings, and publish all at once

clion

ESP8266 toolchain SDK installation

For clarity, toolchain refers to the xtensa-lx106-elf-XXX binaries used to compile your ESP8266 projects with, and SDK refers to the libraries/header files and examples from Espressif to make your life as a programmer easier. Also the tool to flash and monitor your device is part of the SDK.

Get the latest toolchain from the Github repository of Espressif After you've gotten the latest toolchain, follow the remaining instructions on the repository to also install the latest SDK. More information about the installation can be found on their getting started page.

CLion Instructions

Open File > Settings > Build, Execution, Deployment > CMake. Select the profile you want to work on (or create if there's none yet). For CMake options fill in:

-DCMAKE_C_COMPILER="/home/user/esp/xtensa-lx106-elf/bin/xtensa-lx106-elf-gcc" -DCMAKE_CXX_COMPILER="/home/user/esp/xtensa-lx106-elf/bin/xtensa-lx106-elf-g++"

Note: replace with your own absolute paths of where you put the toolchain.

For Build options put -- -j N where N is the number of processor cores in your system + 1. So for a quad core processor N will be 5.

For Environment I had to put ESPPORT=/dev/ttyUSB0 to force the SDK to use the correct USB port. This might not be necessary in your case. Of course replace with the USB port your device is connected to. The USB port can be found on Linux by in a terminal running ls /dev/ttyUSB?. If there's multiple results, disconnect your device to find the difference in result, that being your ESP8266.

CMakeLists.txt in root directory needs reference to IDF_PATH. When using include($ENV{IDF_PATH}/tools/cmake/project.cmake) , use

WiFi and MQTT configuration with SDKCONFIG

Open a terminal in your project directory and run make menuconfig. A custom entry has been added thanks to the Kconfig.projbuild file in the main folder. Here enter the SSID and password of your WiFi. For the MQTT broker URL adhere to the following format mqtt://[username]:[password]@[broker_url]:[port]. Here replace with your own username, password, broker url and its MQTT port.

In order to enable the printing of float and doubles, in make menuconfig, go to Component config -> Newlib and disable Enable 'nano' formatting options for printf/scanf family (it's enabled by default).

To change the default log level, go to Component config -> Log output.