L-1011 Trainer Installation: NAV and COM Radio Head Integration

L-1011 Trainer NAV and COM Radio Integration

Today we finished the VHF NAV and VHF COM Radio head integration with X-Plane. Ben Klang wrote the code for the VHF NAV radios. The VHF NAV radios use a 2 of 5 encoding method and we are reading them with National Instruments DIO cards. Ben wrote a program on a small Linux box that continuously reads the values and sends them on to X-Plane via a UDP DataRef.

We also completed the VHF COM Radio integration. Here, the radios use the ARINC 429 Labels 030 with different SDI numbers to differentiate the various COM channels. For now, we integrated COM1 and COM2 to directly interface with X-Plane. Just as with the VHF NAV tuning information, the VHF COM frequencies are passed to X-Plane via the network as UDP packets.

The video below shows the operation of the VHF COM and VHF NAV radios in our L-1011 cockpit.

Avionics Bending: Mechanical Synchro Signal Producer (Part 7)

Mechanical Digital to Synchro Converter - Test Assembly

Made lots of little tweaks to the individual parts and did a test assemble of some of the components. Eventually the entire assembly will be held together by four rods. Right now, I did a test assembly of the connector plate, the stepper motor plate, the synchro transformer plate and then the section that hold the electronics. Yep, those are cable ties holding the pieces together right now; however, I did this just to double check the sizing of the spacers and to make sure that the gear mechanism lines up.

Mechanical Digital to Synchro Converter

The image below shows the basic Beagle Bone Black in the the rear section of the design. There will actually be a cape on the Beagle that will handle the Stepper motor.

Mechanical Digital to Synchro Converter - Test Assembly

The images show the center core with the Synchro Transformer not yet assembled. I will try to get some rods over the next few days and then put the entire design together and cable it.

Mechanical Digital to Synchro Converter - Test Assembly

So far I am about $86 into this effort. Really want to keep it below $100 if possible. The most expensive part, so far, was the Beagle. Maybe in future iterations I go with a RaPi, but, actually both the BBB and the RaPi are a bit of an overkill for this.

Avionics Bending: Mechanical Synchro Signal Producer (Part 6)

Mechanical Digital to Synchro Converter - Connector and Electronics Bay

I added the connector plate and the electronics bay to the design. The Beagle Bone Black (BBB) will ride in an "electronics bay" on the backside of the design. This will be located behind the synchro transmitter. For the initial design there will be daughter board on the BBB driving the stepper motor (see image below). All connectivity, except for Ethernet, will be brought in through a Tyco Circular Connector. 

Mechanical Digital to Synchro Converter - Connector and Electronics Bay

The image below show the current design from behind. I envision a case around the complete design and a DIN rail holding bracket so that the unit, or multiple units, can be attached to a DIN rail in the simulator. The 26VAC 400Hz power sill also be brought in via the Tyco circular connector.

Mechanical Digital to Synchro Converter - Connector and Electronics Bay

Here is the left hand side view of the current design iteration. 

Mechanical Digital to Synchro Converter - Connector and Electronics Bay

Over time I will probably come up with a more space optimized design. If you have any design ideas please call them out to me. 

Avionics Bending: Mechanical Synchro Signal Producer (Part 5)

Mechanical Digital to Synchro Convert

Here is the first printed and assembled version of the mechanical digital to synchro converter motor assembly. It's a pretty simply assembly and together with the stepper motor and the synchro transmitter and the optical sensor I am about $22 into the project. In the image below you can see the proposed location of the optical sensor.  Next will be to design the plate that holds the Beagle Bone to drive the stepper motor with.

Mechanical Digital to Synchro Converter

Once I get a little further with the design I will put the CAD files on grabcad and the code on github.