The problem I have with that is no more GPS align, makes the telescope look like a robot, which is cool.
So let's try to replace this wonky GPS with something home brewed, based on this cloudynights thread.
The idea is to replicate the serial board of the Celestron with a cheap microcontroller that will convert the GPS data into Celestron serial code and transmit them in TTL.
Since I was dabbling or blabbing in electronic 2 years ago I have a few parts that I can use. A nodeMCU mini and a Beitian BN-180.The BN-180 works at 9600 bauds by default.
Connecting the proper pin requires to translate D pin name into GPIO, GPIO is what arduino understands.
Testing it with the full example in the tinyGPSPlus library with proper pin results in this
Switched over to a Arduino Nano because the Nano can take up to 12V in and output 3.3 or 5V, oh and the digital signal is 5V compatible with the Nexstar.
It works better with the BN220 and gets a lock for 7 sats indoor, but then loses it when I use the computer, I think the proximity to 3 large LCD screens scrambles the reception.
It would be nice to use the quality japan made patch antenna of the celestron, it seems to use a MHF3 ipex connector which doesn't fit the UFL of the new GPS module. I left a note on eevblog forum :) I know aliexpress has that stuff but i don't want to wait 2 weeks.
This NEP-7N gets 5 fixes within seconds but then drops when the antenna is moved.
Onto the wiring.
Get Rj12 from ebay
Use the desinsulators to expose a few wires
tin with this cheapo excellent active head soldering iron, it's fast!
Beowulf made it work https://github.com/LordBeowulf/nexstar_gps
Here is the correspondence between the rj12 and the internal cable.
