try to connect the mount using USB cable and see any miracle happen? Pulse guiding either doing great with USB or RS232.

Hm..does it mean that the BT connection is not good enough to support guiding?

I still think that cable still play a very important role in transmitting data without failing.

My personal experience was that BT is even more unreliable than Wifi connections but it could also be just delusion

It's true. There is a noticeable delay with BT over USB with serial TTL adapter.

Hi all i noticed exactly the same thing over the weekend. Bluetooth works great inside my house with just the mount connected. Once i attached bluetooth moonlite focuser it starts to play up. Add guiding to the mix and forget about it, it falls over within a minute. It seems like there is just way too much data being transfered and bluetooth is just not up to the task. After changing to eqmod USB cabled connection the thing ran all night, no issues with pulse guiding (no ST4 cable) with a ASI 120MC and 2x2 binning and SER algorithm (looks to me that it is better than the smart algorithm, i don't know why, just an observation after using both).

One thing i did notice was internal guider worked flawlessly on my first target. After aligning on my second target and clicking on guide, the internal guider did not guide properly. I had to restart the computer to get the guider to recalibrate for successful guiding.

Is there is a way to just reset the internal guider calibration and have it recalibrate on a new star without having to restart everything?

regards

To clear the calibration data, click the trashcan next to the Guide button.

I should use my glasses, I didn't even see the button, cool thank you

Really appreciate all the responses! On next occasion I will compare, BT vs USB - still I wonder why BT from a technical perspective would not be good enough, is it really that much data?

Anyway, wanted to ask this:

What guide rate is recommendable? By default I was using 0.5, now I read that 1.0 would be preferred - for phd2.

Then: What minimum pulse rate do people use? With a 500mm scope (thru oag), and asi120, would 1000ms or even more would make sense?

Lastly, to which extent would autostretch have an effect on the guiding? Apart from increasing visibility of stars to the user?

Many thanks as always! Helge

I use HEQ5 Pro with EQDIR-BT dongle with PHD2 and have recently made some changes to EQMod driver for this purpose. The original code didn't take into account communication delay with the mount which is around 50ms per command when using BT and around 16ms when using EQDIR cable and 32ms when using PC Direct mode via the hand controller. This made each pulse essentially that much longer. Also the code used timer for all pulse lengths which made short pulses quite unreliable. Last issue was that if mount status query timer happened to hit during the pulse duration, the pulse got significantly longer as command to end the pulse got delayed. These issues should be remedied by current EQMod driver version from nightly which added configuration items to ignore very short pulses and configurable limit how long pulses are handled synchronously. The value for minimum pulse should be around the communication delay so 50 ms for BT, less for wired connection, the default value of 10 ms is very conservative. Default value for timer threshold (100 ms) is probably good as is, but I've used slightly longer 150 ms as the limit myself.

As for the guide rate I've settled on 0.5x after testing 0.3x, 0.75x and 1x, it seems to be a good compromise between correction speed and not over correcting. I'm not sure what you mean by minimum pulse rate, I use 3s exposures so PHD2 does corrections only every 3s to average out effects of seeing. Sometimes I use 2s or even 1s, but 3s has proved to be good compromise.

I tested with Jarno's changes yesterday and everything worked fine. Of course, I didn't have issues before (using EQDir cable, so latency wasn't much of an issue), but the results are great nonetheless!

Dear Jarno,

I was fascinated reading about the enhancements you made. Great job!!!

I erroneously wrote minimum pulse rate, should just have been minimum pulse (length).

Best, Helge