Hand controller for AzGti

[vlaiv]

Well, my new Az Gti arrived, and it's rather nice looking and operating mount.

I would like to add tactile hand controller to it, but purchasing SynScan V5 hand controller at more than 150e (delivered) is too expensive for what I had in mind.

There is a SynTrek controller in my box of old bits and pieces (from Heq5 syntrek model that I no longer use because I control that mount via eqmod / laptop), but as far as I can tell, that one is build for 5V TTL while Az Gti works with 3.3V TTL and I'm not sure they will be compatible.

There is another issue of them having different connectors - so it's not simple matter of plug and try - hand controller is using RJ45 connector, and AzGti is using RJ12. Luckily there is pinout for both, so I should be able to make "adapter" with a bit of skill and few bits (male RJ12, female RJ45 and a piece of cable).

and

But can it damage mount if it provides 5V TTL? (as far as I know latest Skywatcher mounts use 5V tolerant 3.3V TTL, at least AZEQ6 and EQ8 do, according to EQMOD page):

This hand controller aside, I have idea of making something very interesting that will serve the same purpose:

There is now arduino model with Wifi (no need to purchase shield) for less than 30e (maybe even less on aliexpress) and there are keypads for it like this:

I'm no stranger to programming, and AzGTI is using UDP protocol, and I'm fairly certain that I could at least sniff out "commands" if I don't find protocol specs online for it. This means that for about 30-40e and a bit of programming I can have wireless tactile hand controller for AzGti.

Only problem with this approach is of course  - ugly looking keypad not suited for astronomy mount. Does anyone know something similar that will have up/down/left/right + few function buttons keypad that can be used with arduino controllers? I was not able to find anything online.

Or maybe programmable wifi remote controls? There are cheap ones for about 10e or less - but those work as HID devices and you can't program them in traditional sense (although you can assign actions for each button via software - but that is not something that I'm interested).

Another option would be to get remote control (some generic) and then just use keypad matrix of it and attach it somehow to arduino - but I don't know enough to do so myself, and most of boards for remote control are "integrated" with other electronics and don't have matrix separate to extract it easily.

In any case, feedback would be welcome on any of above approaches, or alternatives that will get job done (but are not overly expensive).

[Dr_Ju_ju]

A cheap way, put a box in the 'middle'  with a RJ45 socket at either end, or an RJ45 socket one end & flying lead terminated in an RJ45 connector, (chopped down network lead) then inside the box fit a some 3.3v Zenner diodes, to limit voltage swing. You'll also probably need a couple of resistors to current limit when the zenners are fired.... 

 

[lux eterna]

1 hour ago, vlaiv said:

Another option would be to get remote control (some generic) and then just use keypad matrix of it and attach it somehow to arduino - but I don't know enough to do so myself, and most of boards for remote control are "integrated" with other electronics and don't have matrix separate to extract it easily.

In any case, feedback would be welcome on any of above approaches, or alternatives that will get job done (but are not overly expensive).

Some time ago I built myself an Arduino "astro hub" which has three different duties :

• It manipulates the ST4 signals coming from my NexGuide, going to the HEQ5 Pro. This (almost) cancels out the small and fast PE coming from the RA motor itself. I will write a separate thread about that.
• Dual intervalometers for two different dslr´s.
• Handset emulator for the cabled NexGuide handset.

The handset emulator might be something you can do in a similar way.

(Anyone wondering what that weird "arm" is ? It´s a mirror on a flexible arm, so I can see (in reverse of course) the NexGuide display without breaking my neck. I used a cheap flexible usb led lamp for that).

 

I use the Toshiba remote for this, the bottom IR remote, very small and handy to use, is intended for my current project which is a very small and portable imaging rig. Both remotes can be found on Ebay.

Besides a few led´s, the Arduino also has some audio feedback via a buzzer, so I know what it does.

Ragnar

 

[vlaiv]

46 minutes ago, lux eterna said:

I use the Toshiba remote for this, the bottom IR remote, very small and handy to use, is intended for my current project which is a very small and portable imaging rig. Both remotes can be found on Ebay.

Besides a few led´s, the Arduino also has some audio feedback via a buzzer, so I know what it does.

I was looking at this but always "objected" the fact that it is IR type remote and thought that I would need to point it towards the scope / mount for some reason, but you are quite right.

Arduino with WIFI and simple IR detector (there is plenty of tutorials for that online) can pick up remote commands and translate those into UDP packets sent over wifi to command the mount!

Excellent idea!

[lux eterna]

Thank you @vlaiv

I may add that the reason I choosed the (Omron) Solid State Relays instead of ordinary opto couplers is that my NexGuide did not like the voltage drop across the opto couplers. These SSR´s have much less voltage drop.

Having used this IR thing for a while, I wanted more... like additional working range and two-way communication. The Toshiba remote has lots of free space inside, so I put a small Arduino Beetle and a HC-12 radio module inside it (in fact it is a Bluetooth Beetle but the BT has very low working range). And of course I put another HC-12 by the telescope side Arduino.

In the pic below you can see an IR receiver that is placed directly above the original IR transmitter, this is kind of an eavesdropping device for the Beetle, which interpreted the IR codes and then sent these to the other peer. I blocked the outside of the transmitter with some tape, to disable remote IR transmitting.

I also have a buzzer here for audio feedback - one signal for "One minute left of current exposure", another for "Wake up ! ST4 signals have disappeared !" (which is a cloud warning) etc etc.

The yellow package is a buck converter to feed the HC-12 with 5V. The converter itself was generating huge amounts of RF noise so I had to wrap it in many layers of plastic and aluminium foil, that helped a lot.

Ragnar