SmarterConfig

A utility for ESP32 device provisioning to WiFi.

A challenge of ESP32 devices is getting them their first WiFi credentials and reconfiguring them in the event of a failure or device move.

SmarterConfig is BLE-based configuration for communication between an app and a single device.

Specifically the reason for SmarterConfig is several factors:

1. The ability to configure a single device, in the event that multiple ESP32s are nearby.
2. A status coming back to an app, showing success or failure of connecting to the wifi network.
3. Storing credentials on the device via LittleFS rather than direct EEPROM.

Comparison to other approaches

1. SmartConfig - unlike SmartConfig, the network BSSID is not necessary. The ESP32 controls its own WiFi so the app can be connected to 5ghz or a different network.
2. WiFiProv - WiFiProv did not work.
3. Custom device web-app - end user configuration is a bit harder, as they need to connect to your custom SSID and use the app.

Requirements

SmarterConfig requires several libraries. A sample platformio.ini

[env]
monitor_speed = 115200

[env:esp32dev]
platform = espressif32
board = esp32dev
board_build.filesystem = littlefs
framework =
	arduino
#	espidf
platform_packages = framework-arduinoespressif32 @ https://github.com/espressif/arduino-esp32.git#2.0.9
build_type = debug
monitor_filters = esp32_exception_decoder
lib_deps = 
	bblanchon/ArduinoJson@^6.19.2
	djgrrr/Int64String@^1.1.1
	h2zero/NimBLE-Arduino@^1.4.1
board_build.partitions = customPartition.csv
build_flags =
	-DARDUINO_ARCH_ESP32

Custom Partitions, because BLE libraries are large.

# Name,   Type, SubType, Offset,  Size, Flags
nvs,      data, nvs,     0x9000,  0x5000,
otadata,  data, ota,     0xe000,  0x2000,
app0,     app,  ota_0,   0x10000, 0x1C0000,
app1,     app,  ota_1,   0x1D0000,0x1C0000,
spiffs,   data, spiffs,  0x390000,0x70000,

Examples

See examples/provision.cpp for a sample device app.

See examples/flutter for a sample Flutter connecting app.

BLE Service and Commands

• Configuration Service 97F87C3E-F965-45EF-87DC-E1F0FF8C695A
  • Command to write FFFC70B6-4A21-4661-A2DB-9E0378902787
  • Command's Response to Notify 74121C41-5433-428F-B6F0-9B8479251785
  • WiFi Status to Read. Notify will be blank, informing the app to read new value. F802156A-FBE0-11ED-BE56-0242AC120002

Commands

Scan

The ESP will scan nearby WiFi APs and provide a list.

{"c": "scan"}

{"generated":87840," nearby":[{"ssid":"network1","rssi":-34,"encryption":"wpa2"},{"ssid":"Network Number 2","rssi":-89,"encryption":"wpa2"}]}

Connect

The ESP will attempt connection to this network. If credentials work, the device will save them across future reboots.

{"c": "connect", "ssid": "network name", "pass": "P@ssword"}

In the event of a success, the device will notify on the WiFi status characteristic and wait a short time before rebooting.

In the event of a failure, the device will respond on the Command Response characteristic and notify on the WiFi status characteristic, which can be read for the failure status.

{"status": "failed"}

Flow

graph TD;
    initializeFS[Initialize LittleFS]
    checkFile[Check WiFi credentials file]
    initializeFS-->checkFile
    tryConfig[Try Connection]
    checkFile--Exists-->tryConfig
    bleSetupStart[BLE Setup Start]
    checkFile--Doesn't exist-->bleSetupStart
    tryConfig--Fail-->bleSetupStart

    exit[Normal App]
    tryConfig--Succeeds-->exit

    startTimer[Start powerdown timer]
    bleSetupStart-->startTimer

    bleLoop[BLE Loop]
    startTimer-->bleLoop
    timerExceeded{Timer Exceeded?}
    bleLoop-->timerExceeded

    powerOff[Deep Sleep]
    timerExceeded--Yes-->powerOff

    receiveCommand[Receive Command]
    receiveCommand-.No Command.->bleLoop
    timerExceeded--No-->receiveCommand
    updateTimer[Update Timer]
    receiveCommand-->scan
    scan[Scan]
    connect[Connect]
    receiveCommand-->connect
    scan-->updateTimer

    tryNewCreds[Try new credentials]
    connect-->tryNewCreds
    tryNewCreds--Fail-->updateTimer
    saveAndReboot[Save and Reboot]
    tryNewCreds--Succeeds-->saveAndReboot
    updateTimer.->bleLoop

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