Hello All,

I am in a mighty struggle with serial protocol. Esp. how many configurations there are that will make it not work.

Ultimate plan is to use a serial Bluetooth dongle at the mount (AP1200 with GTOCP3 V2 chip).

But for now I just want to see that a text terminal program on the PC can talk to the PC can talk to the GTOCP3 and get ASCII answers. And that's just my question. If I hook up the laptop to the GTOCP3 (the way I up to now always do) via serial cable and serial-to-USB adapter, is there a simple 'Hello' -> 'OK' conversation that I can have with the controller? Just so that I can see that communication is established. Something like an 'AT' ->'OK'. In plain ASCII. Using 'PuTTY' on the laptop. What's the procedure? I understand that the AP driver sends tons of data between the laptop and the mount. I don't even want to include the driver here. Just type on the keyboard, see the echo, hit a command + enter, and see the answer from the controller. (preferably a non-destructive command)

BTW, the BT adapter wants to know if the port is DCE or DTE. Can someone answer for the GTOCP3 ??

Thanks,
Gert

Hi Woody,

Thank you for the kind feedback. My own experience is that these things don't work for me 'out of the box' so I have to travel the path of step by step debug / understanding / fixing / deployment. To me that also let's me understand why something works, and what I did to make it work. I'll keep looking for a way to establish a known-good terminal to GTOCP3 communication by existing cable and then step by step deploy the BT.

Thanks & Clear Skies,
Gert

Hi Gert,

Since a PC is the "terminal", so the CPx is the data communications equipment, DCE.  A standard straight-through RS-232 cable is used from a computer or USB-to-serial-converter, to the unit.

We use dumb data terminal programs like TeraTerm and HyperTerm *ALL* the time, in exactly the manner you describe.  The command set has it's origins in the old LX200 textual command set, so it is easy to issue them manually for diagnostic purposes.  The command set is published on the AP web-site.  However, examples of commands I use regularly to determine if a unit is alive, "reachable", and that I am even using the correct comm port in the computer, include "read version"  :V# (three characters), and "read local time"  :GL# (4 characters).  You'll want the terminal emulator "local echo" enabled as the CPx does not "echo".

The moment you power up the unit, it will transmit a single character, "1".  That way you know the unit is powered and the embedded software is actually trying to doing something.  This may be the single most powerful diagnostic feature. The serial communication parameters are also published on the AP website.  But to summarize here for ease in setting up the terminal emulator:
9600 baud, No Parity, 8 bits, 1 stop bit, No handshake.  Occasionally, folks "complain" about the lack of parity, but the serial interface remains the most reliable by far.

Happy Hacking!

Regards,
Mike Hanson

Hi,

When I test this on the bench with the GOTCP3 (V2 chip) removed from the mount and disconnected from motors (AP1200), will it impair stored data on gear phase / PEM / disrupt operation once re-connected to the mount ??

Thanks,
Gert

Ultimate plan is to use a serial Bluetooth dongle at the mount (AP1200 with GTOCP3 V2 chip).
But for now I just want to see that a text terminal program on the PC can talk to the GTOCP3 and get ASCII answers.

Cheers,
Gert

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