Category Archives: Astronomy

05/18/19

Evolution EAA Computer Mount

Due to the horrible light pollution here in San Jose, CA I decided to try out EAA- Electronically Assisted Astronomy. Traditional astro photography (AP) is actually really hard and time consuming. EAA is a lot easier and lot faster, although the results aren’t as nice as you can get with AP.

One of the big advantages of EAA is you can use a simple Alt-Az mount like my Celestron Evolution EdgeHD 8″ SCT since you’re taking dozens of shorter pictures rather than much longer photos which require excellent tracking (polar alignment) and stability.
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03/19/17

ESP-DSC Works Not Well!

So yesterday I was all happy that I got my prototype ESP-DSC working. This ended up being short lived as I realized this morning that while it does technically work, the ESP8266 can’t keep up with two medium resolution (2,500 CPR) encoders.

Ironically, I found out that the code was too slow when I started to optimize the code and I realized that the code I has was very very conservative. My original optimization was to speed it up, but maintain that conservative ethos. I figured while I was editing the code, I might as well also add a test to see if the ESP-12F was dropping interrupts… Continue reading →

03/16/17

New low cost digital setting circles: ESP-DSC

So a few years ago, I announced TeensyDSC, project that brings telescope digital setting circles to the iPad and Android devices using WiFi. I’ve been using my TeensyDSC successfully with my telescope and SkySafari on an iPad for a few years, but one thing always bothered me about it: the “COGS” (cost of goods sold) of the TeensyDSC was really expensive: nearly $100. A lot of that cost was in two parts: the Teensy 3.1 ($20) and RN-XV WiFi module ($35).
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11/17/14

A working basic TeensyDSC board

I recently got my first generation PCB in the mail from OshPark and I’m happy to say that the board works just like I had planned! I was able to do some basic testing using 10,000 step encoders, but due to the power of the Teensy 3.1 board and being able to use interrupt driven decoding there shouldn’t be any problem handling 100,000 step encoders if you so desired. The good news is that the board did a great job of reporting the position of the encoders to Sky Safari Pro running on my iPad via a wireless WiFi connection!

Renderings of the board I actually ended up using:

teensydsc-top-v0.5

teensydsc-bottom-v0.5

Photos of the board with the necessary components installed:

TeensyDSC Simple (populated) Top

TeensyDSC Simple (populated) Bottom

Notice there are some missing parts on the PCB.  That’s because so far I’ve only soldered on the parts necessary to power it via USB.  The missing parts are for powering it via 12V DC.

It also fits nicely in this small plastic enclosure I have:

2014-11-17 21.50.29

2014-11-17 21.48.12

As you can see, this board is smaller and much simpler then the earlier board I designed. I did this because it wasn’t going to be possible to fit the original board in the small plastic enclosure I had picked out and most of the features I wasn’t actually going to use/need and I wanted to focus on getting the basic DSC features tested and working.