A Comprehensive EBL with Everything You Want

I have plans to build my own EBL for the motorhome. An EBL is essentially an electrical center adapted for a motorhome, where you connect batteries and consumers. Here you'll find fuses and other things. However, they are quite basic, though in the newest motorhomes, smarter systems are starting to appear.

I intend to address the most significant shortcomings of the existing EBLs and also add a bunch of new possibilities.

Ideas

Here I write down all the ideas that would be interesting to include, adding more over time.

Charging

• [1] Connection for external solar charger
• [1] Connection for external leisure battery charger
• [1] Connection for charging the starter battery ????
• [1] Built-in charger for leisure and starter battery
• [1] Prepared for connection of a DC/DC converter

Inputs

• [1] Temperature and humidity measurement inside the EBL
• [2] Temperature bus for external measurement
• [4] Voltage sensing inputs (push button, light sensor, alarm contact, motion detector…)
• [1] I2C bus for a variety of sensors
• [1] Connection for D+ from the alternator
• [2] Connection to ultrasonic water level meter

Outputs

• [4] 8 amp fused, controllable outputs (water pump, radio, non-dimmable lighting…)
• [4] 8 amp fused dimmable outputs for lighting (LED or incandescent bulbs)
• [4] 25 amp fused, controllable outputs for various purposes (steps, grey tank valve)
• [1] Connection for compressor and condenser fridges
• [1] Output for NEOPIXEL strip (LEDs that can display different colors)
• [1] 3x4 amp output for RGB LED strip (mood lighting)
• [?] Current measurement on certain consumers

Communication (standard)

• [2] CAN bus (vehicle and living area)
• [1] WiFi with external antenna
• [1] Bluetooth
• [1] Serial port for flashing, possibly USB
• [2] NEOPIXEL LEDs for status indication

Communication (with plugins)

• [1] 2.4GHz for remote control with NRF2401 (battery-powered door contacts, for example)
• [1] Port or space on the board for connecting a 4G/5G module (remote control and alarm)
• [1] Port or space on the board for GPS
• [0] No LAN port, too much complicated software
• [1] TIN bus for communication with Truma would be nice!

Miscellaneous

• Connection of power consumers with 6.3mm or 2.8mm flat connectors
• Connection of sensors with spring-loaded terminal block
• 12v relay for on/off with MOSFET (instead of relay)
• ESP32-S3 as the main processor, ESP32-S3 as the I/O processor

Functions

• There should be various operating modes: night, day, driving, with/without connection to 230V, winter storage, low power for minimal consumption
• Should be able to monitor/control via 4G/5G and/or WiFi
• The CAN bus can read certain data from the vehicle's system and act on it
• Additional sensors can be connected via the I2C bus (humidity, sound ...)
• External display can be connected for status and operation
• Wireless battery-powered accessories according to 2.4GHz can be used
• Control of color and brightness of LED strips
• More accurate measurement of water levels
• Moisture measurement during winter storage
• Alarm functions with door contacts, motion sensors, light measurement, sound measurement…
• Current measurement of consumers
• Automatic retraction of steps
• Alarm when the water tank is filling and becomes full, possibly automatic shutdown
• Alarm for temperature and humidity
• Possibly integration with Truma for reading and operation
• Heating control for LiFePO4 batteries
• Self-test

Links

Components

Givare

Waterlevel sensor A02

Protocol S20

Waterlevel sensor A22

Protocol A22

Modules

GPS module

Current measurement

ACS758

Software

There are two ESP32-S3 processors, totalling four cores and 8MB flash.

I/O-processor

Handles outputs and inputs, for example:

• Reads 5 digital inputs
• Reads D+
• Reads the power consumption of connected loads
• Controls output-FET, fixed or PWM

Main processor

Handles EBL's logic.

• Controls status-LED
• Communicates on the CAN-bus
• Communicates on the I2C-bus
• Reads any connected GPS
• Communicates with any connected 4G/5G connection

"Tasks"

Read temperature and humidity from ThermoBeacon via BT Read data from the car's CAN-bus Read/write data on the local CAN-bus Read DS18B20 temperatures Control FET outputs, on/off and pwm Read opto inputs including D+ Control on/off of EBL666 based on buttons Control stair steps Read water levels Control the color of mood-LED Measure current from current sensors Publish data to control panel, at least the same as EBL99 Communicate with the "other" CPU, serial? CAN?