Re: Serial to bluetooth for CPC3

Woody Schlom



It’s been many years now, but yes, I did that with my Mach1-GTO.  I used a RN-270 serial to Bluetooth adapter (RN is Roving Networks). 


The SkySafari guys used to sell the identical adapter but they called it their “SkyBT” adapter.  I’m pretty sure they’ve used up their inventory and aren’t selling it any more.  But the RN-270 is still available. 


The RN-270 can be self-powered with two AAA internal batteries (disposable or rechargeable), or through the RS-232 connector, or externally.  There’s an external jack that I think wants 4v – 9v DC (NOT 12v!).  I now power mine almost exclusively from one of those external rechargeable USB Lithium battery packs.  And when you power externally, you MUST insert two AAA rechargeable batteries inside the RN-270 as the external power goes through those internal batteries.  If you use disposable batteries inside – they’ll explode.  And if you don’t put any batteries inside, it just won’t work.


The internal AAA batteries are susceptible to ambient temperature.  And when the ambient temp. drops below around 55°, battery life drops too.  The solution is more expensive AAA Ultimate Lithium disposables (which work great in sub-freezing temperatures), or external power.


I used mine with my Mach1-GTO two ways.  1) controlling the mount with SkySafari-Pro running on an Android phone or tablet, and 2) controlling the mount with TheSkyX running on a Win-7 Pro laptop.  I haven’t tried it with Win-10 Pro yet, but I’m sure it still works.


The “trick” to using Bluetooth on a Win laptop (at least it used to be) is a little utility program called COM2TCP.  At least when I did this, you had to have that little utility to connect using Bluetooth.  And I see that there’s now a Win-10 version of COM2TCP.  So that tells me, it’s still needed.  The utility isn’t free, but it’s inexpensive and works.


After that, I don’t recall the settings for TSX, but I’m pretty sure I have them written down - somewhere.


P.S.  Wireless range with the RN-270 is amazing.  They claim up to 300m (330 ft.).  I don’t know about that, but I’ve successfully used mine at 75 ft.  Of course the further away it is from the Bluetooth device at the other end, the harder the transceiver has to work – and therefore, it uses the batteries faster.


Hope that helps.




From: [] On Behalf Of drgert1 via
Sent: Friday, August 28, 2020 12:01 PM
Subject: [ap-gto] Serial to bluetooth for CPC3


Hello All,

Is someone using the CPC3 (older generation AP mounts controller) with serial ports with a Bluetooth adapter to connect to Windows10 laptop (with Bluetooth built-in capability) ?
Expectation is to have this transparent to AP driver on the laptop  and connected software.

I.e. this device mounted at CPC3 serial connector :

Clear Skies,

Join to automatically receive all group messages.