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Lithium Starter Batteries

This is a catch-up post, not a very recent activity. It was a while back that I deep discharged my starter batteries again. Had not started the truck for a while and the lead batteries were flat again .. That was the signal for me to finally get the swap done to Lithium batteries. I am tired of lead batteries failing just because they were a bit discharged.

It is tight under the bonnet and my batteries have terminals on the side and not on the top because they would not fit anymore. The Lithiums are 40aH batteries and are […]

Electrical Signals

By |June 18th, 2015|CONCEPTS|0 Comments

Most of the electrical signals which need connection and processing are defined. There are a few components not yet defined, but the majority is. This list groups the signals by signal type in order to identify the number and kind of interfaces the network nodes need.
The next step is to assign the signal to a location in the van, which then leads to the identification of connection boxes and network nodes and their location. All network nodes are connected via the CAN bus and exchange information with the central system.
Manually switched lights – (can be turned off by […]

Ethernet CAN Bus Gateway

By |March 25th, 2015|CONCEPTS|0 Comments

The TAS has two Ethernet/CAN bus gateways for reason of redundancy. If one fails to respond the second one is activated to take over the message relais function. The gateway simply forwards the CAN bus message sent over Ethernet to the CAN bus client and realais the response back to the sender over Ethernet. I stated at another occasion that I decided to use the CAN bus because of the number of client processors and the fact that Ethernet would require far too many switches (ports) and cables to connect each client. The CAN bus is a real bus […]

CAN Bus Program

By |March 22nd, 2015|CONCEPTS|0 Comments

This chapter is not really for every one. Maybe a little too technical for the average auto electrician. This is an early version of an Arduino sketch for a network node reading temperature values from digital temperature sensors ($1.80 each) and sending the data to a gateway with Ethernet port to be forwarded to the central processor for processing and display. This is not a programming lesson, but the few who might be interested to see what an Arduino sketch looks like may have something to ponder over. For an IT person this is probably peanuts, since I used […]


By |March 22nd, 2015|CONCEPTS|0 Comments

All the electric signals in the van are going to be controlled by the TAS and all sensors have to be connected also. The signals and sensors are spread all over the van and it would be rather daunting to connect them all back to the central processor. One reduces the complexity of such an installation by building a network of nodes, which are processors handling local signals and being connected with each other for communication.

I am using Ethernet for some of the connections but with a larger amount of nodes in the network Ethernet is not really the […]

Test Environment

By |March 11th, 2015|CONCEPTS|0 Comments

Most of my tests have been done on the breadboard or free air connections between boards. This works with a few components on the desk but when it gets to the point that one wants to test any kind of integration between components it becomes difficult to keep an overview and more importantly making sure one does not create shorts or bad connections. I use lab power supplies, which ultimately is not a problem for shorts because the lab supplies handle that nicely by limiting the current or cutting the voltage. Nevertheless a more solid setup was needed.

I had […]

HVAC Remote Control

By |February 25th, 2015|CONCEPTS|0 Comments

Another step along the way of full automation has been made today. I finished the page for aircondition control with two heads, one in the kitchen/living area and one in the bedroom. The heads can be switched between the two locations and are connected to the same outdoor unit. The right most temperature scales actually control the target temperatur for each headunit by dragging the red bit to the desired temperature. This will be the same concept on the phone remote control.

Each of the headunits run to the desired temperature, if achievable, but the switch over between the two […]

Battery Monitor

By |February 25th, 2015|CONCEPTS|0 Comments

A major component of the van are the battery packs. Lithium technology brought the weight down considerably and increased cycle times and higher discharge levels make the technology quite attractive. There are a few downsides though. One has to be careful with the charging regime not to overcharge and also make sure that each cell (4 in a 12V battery) has the same voltage, meaning the cells are balanced. The battery needs a BMS (Battery Management System) which monitors the cells and will disconnect a charge line or a load line in case of over charge or over discharge.

It […]

Security IP-Camera

By |February 18th, 2015|CONCEPTS|0 Comments

Today my IP-Camera arrived from China via DHL. It took only 5 days from time of order. Wrapped 3 times in bubblewrap and lots of tape inside a DHL bag. Very nice product, software and documentation on CD and additional software through web download. Was easy to set up. Just change ip of one pc to the default network of the camera, login with browser and default user/password, change ip to local subnet, reboot the camera and the live stream was visible in the browser window after downloading the plugin from their website. All took less than 15 minutes. […]

GUI – Holding Tank Control

By |February 12th, 2015|CONCEPTS|0 Comments

Above picture show the control page for the holding tanks. Tank level gauges display the level in each tank and threshold settings will create alarms when the level goes under or over certain values. This allows automatic clearing of the tanks with a flush cycle for the black water tank.

The activity buttons are not on the page yet. Both aggregate functions and elementary functions are available.

An elementary function is a simple command to open one valve or start the pump, however the pump start will not be executed unless one valve is open. The drain valve for example will […]

GUI – Control Application

By |February 8th, 2015|CONCEPTS|0 Comments

The pictures in the previous chapter showed a first version of the graphical user interface for the control application. It pictured the light switches in the indoor section. I start with the light switches because it is the easiest part to implement from a technical point of view. The above picture is not original resolution. Original size is 1364 pixels wide, the picture above is compressed to 800 pixels wide, everything looks smaller. I decided for a 15″ screen because I wanted more items on the screen at the same time with a reasonable size and not going through […]

Technologies And Concepts

By |February 5th, 2015|CONCEPTS|0 Comments

A quick overview of all the different technologies and technical concepts I am using for the control system and the van. These are points of interest which are not common in RV’s or vans.

Udoo with Freescale i.MX 6 CPU and Atmel SAM3X8E ARM Cortex-M3 CPU (same as Arduino Due)

Arduino Uno with ATmega328

XBoard V2 with Atmega328P low voltage version with Arduino bootloader

Ethernet for loacal Lan

Wifi long range access point with up to 15km reach with WPA-PKA2 protection

Ubuntu Linux 12.04

Samba for file exchange between Windows and Linux

Java as main programming language on Ubuntu and Android

Eclipse IDE for Java development on Windows […]