The Caravan Mover Remote Control Extension
Can be used by:
The mobile phone as a caravan mover remote control for ewiks movers as well as a general caravan
mover remote control is an extension of the traditional switch-box ewiks control system. Connections are made in parallel with the hand-held switch panel so both systems are simultaneously functional. Installation is very simple: it involves: placing and securing the controller near to the existing ewiks electrical switchgear, mounting the power switch in a suitable place on or in the caravan's structure, and connecting 7 wires between the controller and the ewiks installation.. (See Power Considerations below).
Since the remote control relies on radio communication with the mobile phone for its operation, RF shielding should be kept to a minimum. The aluminium side wall of the caravan cannot be avoided and this by itself will not greatly inhibit the transmission of radio waves, but additional metal enclosures should be avoided.
The ewiks-supplied motor switchgear is a very basic 'slam-on - slam-off' relay driven control system, where the motors are supplied with either 100% of electrical power, or none. If a more nuanced control is desired, where motors are driven with partial power, our MotorPac comprehensive motor control system should be considered.
The Android Phone App
Updated for Android V12
Provides all the facilities of the hand-held switch panel as well as allowing mobility all around the caravan to be manoeuvred into position. Phones running Android 6.0 and higher are supported. For convenience the app never goes to sleep, but remains active on the screen until it is shut down, and when it is shut down the Bluetooth connection will be broken.
There is a flashlight button to let you illuminate the scene should you be making camp after dark.
Tapping any motor button, or combination of buttons, while holding down the INCH MODE button sends a command to the Remote Control unit to energise the motor(s) for a single power pulse. This is useful when only small increments of movement are desired. A single power pulse will turn the drive drums through about an tenth of a turn, or 25mm (one inch) of movement, under no-load conditions. Under load this will reduce somewhat. A Red INCH MODE indicator is displayed while INCH MODE is active.
The INCH MODE button is placed to be convenient to the left thumb of a right-handed user. For left-handed operators the INCH MODE button can be moved to the right-hand side of the screen by tapping the red INCH MODE warning indicator when it appears. Use the same method to put it back on the left again. Inch Mode is unaffected by Soft Start and works
independently of it. Inch Mode is an alternative method for making small movements when SoftStart is not
If the mobile phone is equipped with a flashlight there will be a torch-like button at the bottom right of the screen where it can be turned on and off. If the Android level is V6.0 or higher and this is the first time it is used the Android system will ask for permission for the app to use the flashlight. This will pause the app and it must be resumed by tapping it in the Recently Used screen.
The Mobile Phone Remote Control unit requires a 12 volt power supply similar to that which powers the rest of the caravan. It draws a current of about 200mA while working. The cheapest and simplest way to supply it with power is to connect it to the caravan's battery system through a single-pole on/off switch. But there are ramifications to consider.
When not turning DC motors have a very low electrical resistance, which means that they draw a very large current until they get up to speed. Similarly when working hard to against a heavy drag their current consumption rises steeply. The result may be that the caravan battery voltage drops so low that the microcomputer in the controller can no longer function correctly and the unit will disconnect from the Bluetooth network.
There are two solutions available if you do not have a MotorPac with current ramping:
1. Connect the trailing mains-cable to the caravan's power input before and while you use the ewiks motors. This will greatly reduce the power dips and help to keep the battery from discharging too deeply, especially if you keep the duty cycle low. To power the remote control unit from the main battery connect the bridge as shown on the schematic.
2. Power the remote control unit from a separate, dedicated supply battery such as a 12V gel-cell of the type used in burglar alarm systems. The gel-cell will keep the remote control powered for many hours, but not indefinitely. When the power switch set to Off the main battery (and its charger) will be connected to the secondary battery to keep it float-charged. The schematic details how the 2-pole switch assembly included with the controller should be connected between the batteries and the remote control unit and the switch is supplied with each wire tail labelled.