Hi there,
I have investigated recently the
Celestron AUX protocol driver
with my Celestron AVX mount.
One can connect via the handcontrol (HC) to the Celestron AUX protocol driver, and more or less bypass the HC. The HC still can interfere with the driver, however,
by e.g. running
Celestron AUXBUS Scanner
. The HC switches into mode "Pass Through" (I haven't found the option in the HC menu),
it bypass the HC completely and only is a real "pass through".
The output of the AUXBUS scanner is:
$ python ../celestronauxbus/celestron.py hc /dev/ttyUSB0
-------------------------------
AUXBUS SCANNER VERSION 0.9.31
-------------------------------
-----------------------
Starting AUXBUS Monitor
-----------------------
Enter Command:-----------------------
Initiating AUXBUS SCAN
-----------------------
Timestamp - Sender Hex -> Receiver Hex --- Command Hex --- Value
0.050945 - AUXBUS Scanner (0x22) -> Main Board (0x01) --- MB_GET_FW_VER (0xfe) --- []
0.201613 - AUXBUS Scanner (0x22) -> Nexstar HC (0x04) --- NXS_GET_FW_VER (0xfe) --- []
0.352324 - AUXBUS Scanner (0x22) -> Nexstar+ HC (0x0d) --- NXS_GET_FW_VER (0xfe) --- []
0.502859 - AUXBUS Scanner (0x22) -> Starsense HC (0x0e) --- NXS_GET_FW_VER (0xfe) --- []
0.653444 - AUXBUS Scanner (0x22) -> AZM MC (0x10) --- MTR_GET_VERSION (0xfe) --- []
0.704344 - AZM MC (0x10) -> AUXBUS Scanner (0x22) --- MTR_GET_VERSION (0xfe) --- 7.15.8270
0.804293 - AUXBUS Scanner (0x22) -> ALT MC (0x11) --- MTR_GET_VERSION (0xfe) --- []
0.855392 - ALT MC (0x11) -> AUXBUS Scanner (0x22) --- MTR_GET_VERSION (0xfe) --- 7.15.8270
0.954950 - AUXBUS Scanner (0x22) -> Focuser (0x12) --- FUCUS_GET_FW_VER (0xfe) --- []
1.105660 - AUXBUS Scanner (0x22) -> Dew Heater Controller (0x17) --- UNKNOWN (0xfe) --- []
1.256282 - AUXBUS Scanner (0x22) -> CPWI (0x20) --- NXS_GET_FW_VER (0xfe) --- []
1.406959 - AUXBUS Scanner (0x22) -> CFM (0x21) --- UNKNOWN (0xfe) --- []
1.557628 - AUXBUS Scanner (0x22) -> AUXBUS Scanner (0x22) --- UNKNOWN (0xfe) --- []
1.708248 - AUXBUS Scanner (0x22) -> CGX RA Switch (0x30) --- UNKNOWN (0xfe) --- []
1.858948 - AUXBUS Scanner (0x22) -> CGX DEC Switch (0x31) --- UNKNOWN (0xfe) --- []
2.009540 - AUXBUS Scanner (0x22) -> CGX DEC Autoguide Pt (0x32) --- UNKNOWN (0xfe) --- []
2.160172 - AUXBUS Scanner (0x22) -> GPS (0xb0) --- GPS_GET_FW_VER (0xfe) --- []
2.310831 - AUXBUS Scanner (0x22) -> RTC (0xb2) --- UNKNOWN (0xfe) --- []
2.362936 - RTC (0xb2) -> AUXBUS Scanner (0x22) --- UNKNOWN (0xfe) --- 3.1
2.461435 - AUXBUS Scanner (0x22) -> Skyportal Accessory (0xb3) --- WIFI_GET_FW_VER (0xfe) --- []
2.612124 - AUXBUS Scanner (0x22) -> Starsense Camera (0xb4) --- SS_GET_FW_VER (0xfe) --- []
2.762791 - AUXBUS Scanner (0x22) -> Nexstar EVO WiFi (0xb5) --- WIFI_GET_FW_VER (0xfe) --- []
2.913409 - AUXBUS Scanner (0x22) -> Battery Power Cont (0xb6) --- BAT_GET_FW_VER (0xfe) --- []
3.064023 - AUXBUS Scanner (0x22) -> Charge Port (0xb7) --- CHG_GET_FW_VER (0xfe) --- []
3.214661 - AUXBUS Scanner (0x22) -> Starsense Camera SW (0xb8) --- UNKNOWN (0xfe) --- []
3.365312 - AUXBUS Scanner (0x22) -> Dew Heater Controller (0xbb) --- DEWHEATER_GET_FW_VER (0xfe) --- []
3.515953 - AUXBUS Scanner (0x22) -> Mount Lights (0xbf) --- LIGHT_GET_FW_VER (0xfe) --- []
4.167221 - AUXBUS Scanner (0x22) -> AZM MC (0x10) --- MTR_GET_MODEL (0x05) --- []
4.221660 - AZM MC (0x10) -> AUXBUS Scanner (0x22) --- MTR_GET_MODEL (0x05) --- 1485
-----------------------
Finished AUXBUS SCAN
-----------------------
-----------------------
Mount : AVX
-----------------------
-----------------------
Detected Devices
-----------------------
0) AZM MC (0x10) - 7.15.8270
1) ALT MC (0x11) - 7.15.8270
2) RTC (0xb2) - 3.1
Another approach is to build a DIY USB <-> NexstarAUX relay. Based on previous projects:
NexStar™ Direct Telescope Mount Control
and
Homebrew Mount-USB Connection for AUX-Port
I used the proposed diode-resistor tri-state circuit and the tiny
Seeed Studio XIAO SAMD21
.
I first created a prototype and finalized it with the tiny shield.
Scanning it with AUXBUS Scanner:
$ python ../celestronauxbus/celestron.py serial /dev/ttyACM0
-------------------------------
AUXBUS SCANNER VERSION 0.9.31
-------------------------------
-----------------------
Starting AUXBUS Monitor
-----------------------
Enter Command:-----------------------
Initiating AUXBUS SCAN
-----------------------
Timestamp - Sender Hex -> Receiver Hex --- Command Hex --- Value
1.256682 - AZM MC (0x10) -> AUXBUS Scanner (0x22) --- MTR_GET_VERSION (0xfe) --- 7.15.8270
1.508208 - ALT MC (0x11) -> AUXBUS Scanner (0x22) --- MTR_GET_VERSION (0xfe) --- 7.15.8270
4.020671 - RTC (0xb2) -> AUXBUS Scanner (0x22) --- UNKNOWN (0xfe) --- 3.1
6.834152 - AZM MC (0x10) -> AUXBUS Scanner (0x22) --- MTR_GET_MODEL (0x05) --- 1485
-----------------------
Finished AUXBUS SCAN
-----------------------
-----------------------
Mount : AVX
-----------------------
-----------------------
Detected Devices
-----------------------
0) AZM MC (0x10) - 7.15.8270
1) ALT MC (0x11) - 7.15.8270
2) RTC (0xb2) - 3.1
The USB <-> NexstarAUX relay connects via the INDI Celestron AUX Driver and port type USB/HC without problems and allows to bypass the HC completely.
I will polish MCU code within the next days and upload it to github.
Cheers
Thomas
Topic Author
