By far, the most difficult part of a SkyView Assist installation is providing a Bluetooth communications path from SkyView to the Android tablet. In every case, a serial-to-Bluetooth adapter on one of the SkyView’s serial ports is all that is needed. But the devil is in the details.
We provide this diagram outlining how the adapter should be wired. Typically a 9-pin D-subminiature connector matching the adapter is used.
However, the reality is that the adapter only requires a connection to the SkyView serial output line (TXD) (and ground of course and optionally +5V power). The RXD connection is not used and can be omitted with no loss of functionality. The only reason it was included in the first place is so that the serial port could be easily re-purposed at some future date.
Just be sure that the TXD line goes to the input line of the Bluetooth adapter, whether that input is on its pin 2 or pin 3.
In addition, we have found that the Bluetooth adapter does not require its own dedicated serial port. Since it only requires an output (TXD), it can be shared with another device that only requires an input (RXD) if connectors are provided for both devices. (Don’t forget to provide the ground for both devices). One such “shareable” port is the one used for the SkyView GPS (SV-GPS-250 and presumably the SV-GPS-2020) which is typically connected to port 5 in a SkyView system.
In any case, the SkyView serial port output is configured as specified in the documentation Connecting SkyView Assist to the Dynon SkyView
Finally, this serial-to-Bluetooth adapter is one with which we have had much success. It is available on eBay and other places under various names or we will send you one for $15.00 postpaid in the USA with payment by check or PayPal. Just email us at skyviewassist@gmail.com
Note that we have modified this adapter by soldering a wire to pin 9 of the connector for a +5V feed. You still have to provide +5V at a few ma. of course but the Dynon SkyView +5V output on pin 18 of the EMS 37-pin connector can supply it while also supplying +5V to the engine transducers. Here’s a view of the bottom of our recommended adapter:
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SkyViewAssist 