EQDirect Cable

[AndreaLiga]

Hi there. 

I am looking to build a cable to connect my 8 inch Skywatcher  go to FlexiTube Dob to pc or Astroberry.

I can't find anywhere the pinout of the RJ12 mount port. 

Any one ever built one or can address me. 

Regards

[symmetal]

The HEQ5 and AZEQ6 have an RJ45 on the mount for connecting either the Synscan controller or the EQDirect cable. The Synscan  to mount RJ45 to RJ45 is wired 1 to 1 so the details of the HEQ5/AZEQ6 EQDirect cable here giving the pinout of the mount RJ45 is also the pinout of the Synscan RJ45 connector.

Your Synscan RJ45 to Mount RJ12 cable likely has the colours of the wires used visible through the plugs so you can see which colour wires are used for the Synscan TX, RX and Gnd connections, and which pins they are connected to on the mount RJ12 plug. These would be the ones to use on your eqdirect cable for your Dob synscan system.

if the wire colours aren't visible on your synscan RJ45 to RJ12 cable then a multimeter continuity test can be used to check the pin connections. 🙂

Alan

Edit: The AZ-GTi has an RJ12 for the Synscan connection so this may be the same pinout as your Dob which the continuity check above can confirm.

Here's the Synscan pinout

Edited July 17, 2022 by symmetal

[malc-c]

EQDIR cables were originally intended for use with EQ mounts (hence their name).  Whilst it is possible to make one for a Dob, you have to be really careful that you don't end up frying the motor board (which as you know requires the replacement of the PIC micros).  The MC003 motor board has a 6 pin RJ11 socket, it only uses the four inner terminals, but with two shorted which go to the PICs RX and TX pins via two diodes and a few pull up resistors, with one pin connected to RA4 on both PICs, which can only be used as some form of trigger to manage the directional flow of serial signals, because otherwise with the TX and RX pins connected at the connector all that would happen if a FTDI 5v TTL serial adapter was connected would be an echo back to the PC of whatever is sent.

This was discussed on page 8 of the lengthy, but detailed thread repairing a blown motor board - Most of the board I've repaired have been down to people trying to connect their Dobs to a computer which results in popped diodes or burnt out UARTs in the PICs.

You can see this shorting of pins on the two images of the MC003 on that same page.  Top left of the first image below the silk screen R1 you can see the thick track linking the two.  This line is pulled high by R3, and then gets routed to the two PICs va D2 and D3 on the TX lines.

Now I'm not saying it's not possible to connect a Dob with an MC003 or MC004 board to a computer, but it's not something that has been in built by design, probably as an ALT/AZ mount is not one that someone would really use for imaging due to tracking and field rotation issues.  If you do manage to take an FTDI - 232- 5V cable and terminate it with an RJ11 and manage to get it to work without blowing the board then please let us know.  

[symmetal]

34 minutes ago, malc-c said:

EQDIR cables were originally intended for use with EQ mounts (hence their name).  Whilst it is possible to make one for a Dob, you have to be really careful that you don't end up frying the motor board (which as you know requires the replacement of the PIC micros).  The MC003 motor board has a 6 pin RJ11 socket, it only uses the four inner terminals, but with two shorted which go to the PICs RX and TX pins via two diodes and a few pull up resistors, with one pin connected to RA4 on both PICs, which can only be used as some form of trigger to manage the directional flow of serial signals, because otherwise with the TX and RX pins connected at the connector all that would happen if a FTDI 5v TTL serial adapter was connected would be an echo back to the PC of whatever is sent.

This was discussed on page 8 of the lengthy, but detailed thread repairing a blown motor board - Most of the board I've repaired have been down to people trying to connect their Dobs to a computer which results in popped diodes or burnt out UARTs in the PICs.

You can see this shorting of pins on the two images of the MC003 on that same page.  Top left of the first image below the silk screen R1 you can see the thick track linking the two.  This line is pulled high by R3, and then gets routed to the two PICs va D2 and D3 on the TX lines.

Now I'm not saying it's not possible to connect a Dob with an MC003 or MC004 board to a computer, but it's not something that has been in built by design, probably as an ALT/AZ mount is not one that someone would really use for imaging due to tracking and field rotation issues.  If you do manage to take an FTDI - 232- 5V cable and terminate it with an RJ11 and manage to get it to work without blowing the board then please let us know.  

Good point Malcolm.

I'm not sure what happens if you try to control an AZ-EQ6 in Azimuth mode using EQMod. The EQDirect page I linked to by the EQMod project does show the connections for an AZ-GTi. Whether EQMod can then control the AZ-GTi I don't know, but it's odd that it would be included if it doesn't.

In this rather old link, Chris Schillito, who wrote EQMod, says that  EQMod won't drive an AZ-EQ6 in Azimuth mode correctly, and GOTOs will be wrong. EQDirect is just a hardware interface for RS-232 level serial to TTL level serial communication so Alt-Az control is certainly possible using an EQDirect cable if suitable software is available.

Alan

Edited July 17, 2022 by symmetal

[malc-c]

Alan, from reading may post on the EQMOD users group Chris originally wrote EQMOD as a means of controlling his EQ6, and then through popular requests the HEQ5 ratios were added.  He's often stated to people who aske about using it with AZ mounts that "the clue is in the name"  ie EQMOD.   I think the reason it lists some AZ mounts is that they gave options to be used in either ALT/AZ or EQ configuration, so when used as an EQ mount EQMOD works as it would with any of the other supported EQ mounts.  

As Chris and you have stated, goto's and tracking will be off, as tracking only drives one axis, the software is presuming the "AZ" axis is angled to the latitude of the location and not at 90 degrees straight up.

However a lot of this may be in vein as a few days ago I received a PM  from the OP stating that they appear to have blown the PICs on the using a DIY EQMOD cable and were seeking advice on how to replace them.  I have no idea if they had used a standard RS232 adapter that would have applied +/- 12v into the PICs or if it was something else that damaged the PICs..  The OP seems to have some experience in soldering and I've given them some advice on how to go about programming and replacing the PICs (logistics prevents me offering to do it for them) so hopefully one the mount is back up and working they might want to take a look at the SynScan wi-fi adapter which list Dobsonian synscan mounts under the compatibility list

[AndreaLiga]

7 hours ago, malc-c said:

so hopefully one the mount is back up and working they might want to take a look at the SynScan wi-fi adapter which list Dobsonian synscan mounts under the compatibility list

Hi there Malcolm. 

That is what I'm going to do. 

Looks also like that I can make Astroberry talk with the SW WiFi dongle so that I can have a remotely controlled system. 

Thank you for your input and help

Regards

Andrea 

[StevieDvd]

@AndreaLiga

I see from your posts on FB Astroberry group a few days ago that you said  'mount motor control board cooked!' is that incorrect then?

A point to note is when using an eqmod connection the baud rate is normally 9600, but when connecting to a usb port on the mount/handset it is usually 115200 and you should check for the mount type other than eqmod.

The manuals here and here for the mount & later handset show a computer connection is allowed for the mount type. So a cable connection should work.

If you download the synscan app for your PC you can try via the handset usb cable (no diy) and see if that connects. It could be the astroberry settings stopping the mount being recognised.

 

 

[AndreaLiga]

1 hour ago, StevieDvd said:

I see from your posts on FB Astroberry group a few days ago that you said  'mount motor control board cooked!' is that incorrect then?

Hi StevieDvd,

No it's not incorrect. The MC board got fried. 

So I will have to attempt to repair it. 

And if I succeed I'm not prepared to fry it again unless I'm absolutely sure to find the correct cable to connect to Astroberry.

At this stage all the cables and pinouts I've been coming across are not suitable for the AltAz dob mount. 

For this reason I'll be considering a WiFi dongle.

I have a v5 Synscan HC and connection to a pc is possible via the USB A plug no problems at all with a printer cable. 

In a linux environment like Astroberry however I am unable to even though it is contemplated and supported by Indilib drivers. 

[StevieDvd]

Sorry to hear the board is fried. Once you have it setup you can try the synscan app/PC direct connection, if that works then the astoberry should work too - though com port assignment to the correct tty can be picky at times.

Update us when you have the board working.

 

[malc-c]

Steve, the board is an old MC003 with the 16F886's, which run their serial UART at 9600 

I've given the OP as much info and assistance on programming replacements and swapping them out as I can.  The cost to send the board and handset halfway around the world in both directions would make the repair a tad prohibitive.  I could program a couple of PICs and send them to Andrea but as there is some discrepancy over the version of firmware this board uses (having been asked to put 2.09 on one board recently) and if that turns out to be wrong there is no way to revert back without going through the same process again.

[malc-c]

3 hours ago, AndreaLiga said:

I have a v5 Synscan HC and connection to a pc is possible via the USB A plug no problems at all with a printer cable. 

Using the handset in PC-DIRECT mode to act as the interface between computer and mount may be the safest alternative to a wi-fi dongle.  A direct physical connection using an EQDIR cable could put you back to square one again

[StevieDvd]

Malcolm,

I'm not suggesting anything that's destructive.  I think a home made eqdir cable may be the culprit here.

If the board is repaired then safest mode is to try with handset only first, then a simple usb cable as that's allowed for.  If all  okay then perhaps a wifi dongle or eqmod cable recommended by someone like FLO.

[AndreaLiga]

22 minutes ago, malc-c said:

Using the handset in PC-DIRECT mode to act as the interface between computer and mount may be the safest alternative to a wi-fi dongle.  A direct physical connection using an EQDIR cable could put you back to square one again

Hi Malcolm,

I've already taken the EQDIR cable out of the equation. 

Definitely not compatible. 

The wifi dongle would allow me to control my telescope from the comfort of my office. 

With the Astroberry box I have a plethora of instruments and apps that I can access remotely. 

If I had to go via PC Direct mode I would have to have a long cable running from my office to the scope hand controller. I'm not keen on the idea...

This kind of connection is suggested in the Indilib forum at the page dedicated to the Skywatcher AltAz Dob mount driver. However I've tried it several times with no luck! 

 

Edited July 18, 2022 by AndreaLiga

[AndreaLiga]

3 hours ago, StevieDvd said:

Sorry to hear the board is fried. Once you have it setup you can try the synscan app/PC direct connection, if that works then the astoberry should work too - though com port assignment to the correct tty can be picky at times.

Update us when you have the board working.

When I type "dmesg" in the terminal I can see the device connected to ttyUSB0 port. I then punch that value into the port field of the telescope settings in the Ekos. But it always fails connecting. 

Once I fix the board I'll try to re flash Astroberry and see if I get some luck

[malc-c]

17 hours ago, AndreaLiga said:

When I type "dmesg" in the terminal I can see the device connected to ttyUSB0 port. I then punch that value into the port field of the telescope settings in the Ekos. But it always fails connecting. 

Once I fix the board I'll try to re flash Astroberry and see if I get some luck

To verify the board is fried, plug the handset into the port on the motorboard and power up the board.  If the handset displays "no response both axis" or similar and fails to then advance through the set up routine then yes that confirms the UARTs on the PIC, or the diodes have been blown.  If it functions as expected then the board hasn't been fried, and suggests an settings issue when you tried used the USB cable and handset in PC-DIRECT mode between the computer and mount.

[AndreaLiga]

5 hours ago, malc-c said:

To verify the board is fried, plug the handset into the port on the motorboard and power up the board.  If the handset displays "no response both axis" or similar and fails to then advance through the set up routine then yes that confirms the UARTs on the PIC, or the diodes have been blown.  If it functions as expected then the board hasn't been fried, and suggests an settings issue when you tried used the USB cable and handset in PC-DIRECT mode between the computer and mount.

Hi Malcolm.

When the drama happened I had everything connected and upon powering the mount (I was very close to it) I heard two distinct pop.

The two PICs are fried and this is validated by the pictures attached.

This morning I spent some time in trying to find out if other components were damaged but I couldn't find anything under my jewelers loupe.

I might have to carry some more tests with the old fashion multimeter especially on the two diodes and the resistor on the TxRx line close by the RJ11 plug

 

[malc-c]

I think that's concrete proof they've blown (literally!) - Not sure how things are for supply down under, but my normal wholesaler has been showing them as back order only with no date for fulfilment.  The only place I've found them in stock is a listing on e-bay where the guy is selling them at the ridiculous price of £26.99 ea, compared to the £5 I was paying pre-covid. !!

 

[AndreaLiga]

13 hours ago, malc-c said:

I think that's concrete proof they've blown (literally!) - Not sure how things are for supply down under, but my normal wholesaler has been showing them as back order only with no date for fulfilment.  The only place I've found them in stock is a listing on e-bay where the guy is selling them at the ridiculous price of £26.99 ea, compared to the £5 I was paying pre-covid. !!

 

Hi Malcolm,

I should be receiving them in about 3 weeks time from AliExpress. I paid around AU$ 4.50 per piece with about AU$ 7.30 postage. I bought 4 just to be safe.

So all in all I paid around AU$ 25 for the lot.

I spent  the afternoon trying to remove the two cooked PICs (see photo attached).

With U5 however unfortunately 2 pads are gone. Looks like are not connected. From the Datasheet they are the two pins used for programming (Pins 27 and 28 ICSPCLK and ICSPDAT respectively) So if they don't have a pad they still should be fine, am I right?

Regards

[malc-c]

Yes, those two pads are not connected to anything so you are OK.  They are just the last to pins on port B (RB6 and RB7) that also double up as Program Clock and Data.

Well done on sourcing the PICs.  Good luck with the programming.

[AndreaLiga]

14 minutes ago, malc-c said:

Good luck with the programming.

Even the programmer is a couple of weeks away.

Will let you know when done.

And thank you so much for sharing your knowledge!

 

[malc-c]

24 minutes ago, AndreaLiga said:

Even the programmer is a couple of weeks away.

Will let you know when done.

And thank you so much for sharing your knowledge!

 

No worries, sorry can't do more.