NMEA 2000 Fluidmonitor

Table of contents

• NMEA 2000 Fluidmonitor
  • Table of contents
  • Description
  • NMEA 2000
  • Librarys
  • Hardware
  • Configuration
    • NMEA 2000 Settings
      • Instance
      • SID
    • Tank
      • Fluid type
      • Capacity
      • Height
    • Sensor
      • Calibration factor
      • Upper dead zone
      • Lower dead zone
  • WiFi
    • Default Password
    • Default IP address
    • OTA
    • Configuration options
  • Blinking codes
  • Reset

Description

A sensor based on a VL53L0X to determine the fill level in a tank. The VL53L0X is a Time-of-Flight (TOF) laser-ranging module. It can measure absolute distances up to 2m This sensor can be used to determine the fill level in a tank. The sensor VL53L0X is used for this and is a Time-of-Flight (TOF) laser-ranging module. It can measure absolute distances up to 2m, setting a new benchmark in ranging performance levels.

A measurement is taken every second. The average value is determined from 60 measurements.

The system communicates via the NMEA 2000 protocol, sending temperature values and alarms as NMEA 2000 messages over an NMEA bus. Configuration is done through a web interface, and real-time values can be viewed on a website. Additionally, there's a link on the configuration page for convenient firmware updates.

NMEA 2000

The following PNG is send by this sensor.

• 127505

Librarys

• VL53L0X
• NMEA2000
• NMEA200_ESP
• AsyncTCP
• ESPAsyncWebServer
• IotWebConf
• IotWebConfAsync
• IotWebRoot

Hardware

Hardware description

Configuration

NMEA 2000 Settings

Instance

This should be unique at least on one device. May be best to have it unique over all devices sending this PGN.

SID

Sequence identifier. In most cases you can use just 255 for SID. The sequence identifier field is used to tie different PGNs data together to same sampling or calculation time.

Tank

Fluid type

Select the fluid type. can be one of the following

• Fuel
• Water
• Gray water
• Live well
• Oil
• Black water
• Gasoline fuel

Capacity

The volume in liters that can be held in the tank.

Height

This value is used to calculate the amount of liquid in the tank.

Sensor

Calibration factor

You can calibrate this with a 2 point slope. Take one measurement at 50mm and another at 300mm. Write down the value that the sensor measures. Then calculate the factor according to the following formula

factor = (300mm - 50 mm) / ( X1 - X2)

X1 = value for the 300mm measurement
X2 = value for the 50mm measurement

Use the factor as your calibration factor. This 2 point slope should give you a good linear fit.

Upper dead zone

This value determines the dead zone at the top of the tank. If the reading is less than this value, then the tank is considered as full.

Lower dead zone

This value determines the dead zone at the bottom of the tank. If the measured value is greater than the tank height - lower dead zone, then the tank is considered as full.

WiFi

Default Password

When not connected to an AP the default password is 123456789

Default IP address

When in AP mode, the default IP address is 192.168.4.1

OTA

OTA is enabled, use default IP address or if connected to a AP the correct address. Port is the default port.

Configuration options

After the first boot, there are some values needs to be set up. These items are maked with * (star) in the list below.

You can set up the following values in the configuration page:

• Thing name - Please change the name of the device to a name you think describes it the most. It is advised to incorporate a location here in case you are planning to set up multiple devices in the same area. You should only use english letters, and the "_" underscore character. Thus, must not use Space, dots, etc. E.g. lamp_livingroom *
• AP password - This password is used, when you want to access the device later on. You must provide a password with at least 8, at most 32 characters. You are free to use any characters, further more you are encouraged to pick a password at least 12 characters long containing at least 3 character classes. *
• WiFi SSID - The name of the WiFi network you want the device to connect to. *
• WiFi password - The password of the network above. Note, that unsecured passwords are not supported in your protection. *

Blinking codes

Prevoius chapters were mentioned blinking patterns, now here is a table summarize the menaning of the blink codes.

• Rapid blinking (mostly on, interrupted by short off periods) - Entered Access Point mode. This means the device create an own WiFi network around it. You can connect to the device with your smartphone (or WiFi capable computer).
• Alternating on/off blinking - Trying to connect the configured WiFi network.
• Mostly off with occasional short flash - The device is online.

Reset

When CONFIG_PIN is pulled to ground on startup, the Thing will use the initial password to buld an AP. (E.g. in case of lost password)

Reset pin is GPIO 13