Build Thread: Burni

[SPF40plus]

This is getting a bit off track, but if you want your kids to learn programming, the Arduino platform is a excellent place to start.
Lots of cheap hardware and modules available on eBay and the Arduino IDE makes uploading code very simple.

I sent you a PM.

Off track, yes, may mean the need or another thread. See signature for further discussion on the digital dash build. ?

 

[SPF40plus]

Has anyone bought a Thermocouple in Australia recently and have any good/bad experience to share on the product or supplier?

 

[SPF40plus]

Time for an update.

While cleaning out the unbelievable mess that I had made inside the cab this morning (electrical, welding, parts, etc), I found my notes on the central locking system that I installed a few months ago. Of course this got rained on at some point, so is looking worse for wear. I'm posting this up in case you are interested in installing a 24v central locking system, and so I have a record of it.

The system comprises:

1. Mongoose M24 Vehicle security system (including keyless entry with two fobs);
2. 4x Mongoose 24v two wire door motors (there are no longer any master motors available from Mongoose, Rhino, or anyone else in Australia);
3. 3x 5 pin 24v relays (i used FRC7C-SR-1 units from Jaycar):
   1. Pin 85 = trigger;
   2. Pin 87 = normally open output;
   3. Pin 87a = normally closed output;
   4. Pin 30 = positive supply (battery/fuse block);
   5. Pin 86 = ground;
4. 2x inline blade fuse holders;
5. 2x high amperage diodes;
6. Miscellaneous fittings and heat shrink - the relays use male blade fittings.

The reason for all this, is that on a central locking setup there is normally one or two master door motors (these have 3, 4, or 5 wires) and then if there are more doors, then these are slave motors. The master door motors allow the door to be opened with a key, and then for all the other door motors to be triggered. As there is no 24v master available, the following set up allows for central locking with the key fob (but not with the key - this can be done but there are about another 15 components required). As you can see the system (except the first two items) is made of parts that can be sourced from any electronics or auto supply shop.

The security system has a number of features including immobilisation and audible alarm, but I'm not going to discuss these here. They are substantially independent of the keyless entry anyway.

The objective for the setup is:

1. Enable keyless entry (by unlocking all doors);
2. Enable automatic relocking if vehicle isn't accessed, which also means that a mistaken button press doesn't leave the vehicle unlocked;
3. Use the 24v electrical system of the truck, not a 12v sub system (the key reason for this is to minimise battery drain over long periods of non-use);
4. Allow for the external battery disconnect to be used, and allow for instant access to be possible when the switch is closed (and reimpose the alarm at the same time).

To set up the system, I first installed all the door motors - the two front doors were easy as there is already wire access to these doors for lights and mirrors. The additional two wires can be easily added to the loom/conduit. The rear two doors are much harder, and I had to remove the doors so I could drill holes in the doors and in the B-pillar to route the wires into them. Something to note if you are working on one of these FTS700 trucks - they have a piece of parallel flange channel in the B-pillar, which isn't directly attached to anything except the hinges, so if you drill a hole in the interior body work don't expect to be able to pass anything through until you also drill through the PFC. You need to be careful of your drill locations so you don't hit the web of the PFC. The other thing is what to do about the swarf and chips that fall into the void - do your best with this, there are no perfect answers it seems as there is no access from underneath or above.

As a general description, the M24 sends a positive signal on the blue wire to lock, and a positive signal on the green wire to unlock with the respective button press. However, if it suits your purposes you can reverse this, but note the lock/unlock button press also triggers things like setting the alarm state to on, and others if you are using those features. The other thing to note is that in each case the other wire needs to act as a ground (more on this later).

I have connected the blue wire (from M24) to pin 85 of one relay (I'll refer to this as the Lock Relay) and the green wire (from M24) to pin 85 of the other relay (I'll refer to this as the Unlock Relay).

The third relay is use to control the switching and provide an alternative ground for each circuit (I'll refer to this as the Ground Relay). On this relay Pin 30 is connected to ground (be careful with this). The image below shows the general arrangement:



On the left hand side, note the two diode symbols. You have to do this (or something else) so that the control circuit in the M24 will work - it allows the circuit to close in each direction.

The image below shows Lock button press (red dashed line for positive, black dashed line for negative):



The following image shows unlock button press: