BigNG sensor fix

Originally the BigNG fan controller/sensor was reporting 0s for all the analog sensors. After double checking to make sure the sensor were plugged in correctly it was back to the driver to see what was going on.

Again it pays to read the documentation very closely. The BigNG has it's own subset of function to poll analog data. After simple fix temperatures came in correctly. Small post but also gave me an excuse to post how we work with RTS2.

Fixing AstroHaven Enterprises dome driver

Timing is everything and especially so when it comes to computers.

When issuing a command the dome controller will run the command exactly for one second. So when writing the driver the code to open and close the leafs were dead simple. Or so I thought so......

cmdSent=0;
response = '\x00';

while(response != POLL_B_OPENED && cmdSent < MAX_COMMANDS)
{
    sconn->writePort(CMD_B_OPEN);
    sconn->readPort(response);
    cmdSent++;
}

if(cmdSent < MAX_COMMANDS)
{
    return 1;
}
else
{
    return -1;
}

This code simply sends the command and keeps sending till it gets the wanted response. There is a upper limit set in the header file. The variable cmdSent is incrementing to the limit. The limit is just in case something might happen we can report a fail to open or close. A question might come up why we can't simply hard code a number?

Two reason, first is the controller and motors isn't exact. I can't say opening the dome will take X amount of seconds because with age the time to open and close will change. Second this driver will work for all three sizes of AHE domes with same controller. (Heard AHE now ships with different controller) Make it versatile as much as possible.

The problem started when converting the AHE driver from a custom serial driver to the standard RTS2 ConnSerial driver. So simply replaced write and read with the functions of the ConnSerial and tested. Everything worked except the opening and closing.

I worked on this problem for several hours. Mainly it took so long because it was super late and debugging abilities lessen with lack of sleep. :) Can you spot the problem? Hint: readPort() is non blocking......

Originally the serial read function of the custom serial was blocking. So when I replaced with the new code forgot it was non blocking. When this code runs it will reach the upper limit before the leaf started to close or open thus throwing an error and quitting. Quick fix is to sleep giving time for dome controller to move.

while(response != POLL_B_OPENED && cmdSent < MAX_COMMANDS)
{
    sconn->writePort(CMD_B_OPEN);
    sleep(1); //simple fix here
    sconn->readPort(response);
    cmdSent++;
}

Lesson learned, never assume anything and RTFM!

Dome Wiring

Our wiring is out of control! We can't make anything permanent yet because we still have to install major things like the telescope pier. Not to mention we still have some repairs/updates that need to be done to the dome motor system.

In any case, I've cleaned things up a bit and zip-tied some of the longer cables. In the future it would be good to have some shelving or mounting for some of the boxes as well as more tubing or clamps to hold wiring against the wall. On another note, there are some interesting creatures living in the cabling - maybe I'll post a few photos in the future.

Problems of 7/14/2010

In an effort to try to keep on top of issues I have decided to post them. As we solve each problem will write a follow up post explaining how and why we solved it.

Here is a current list the developers (Matt and I) are working on.

Software

• BigNG sensor has analog sensor dumps but libtban does not return a temperature when calling analog sensor individually. - fixed
  
• Apogee Alta CCD camera driver is currently not working. Problem lies in setting binning other than 1x1 will cause camera to hang on next exposure.
• RTS2 UPS integration has not been started yet. - fixed
  
• Convert RTS2 driver to use general SerialConn versus Vermes template. - fixed
• Meade LX200 driver not talking correctly to LX200GPS - fixed
  
• Filter driver - done just needs ported to RTS2 interface
  
• AstroHaven Enterprises dome driver not working correctly - fixed
• Add udev rules for all the USB devices
  

Hardware

• Still waiting on AstroHaven Enterprises dome motor replacement.
• Webswitch III died last weekend. Waiting for support to call use back. Maybe defect/warranty case.
• Still need to spec out computer capable of extreme temperatures. Computer still needs to have PCI slots and serial ports. Don't want to use USB<->Serial
• Draw a plan for UPS during extreme temps
• Add lens heater on LX200GPS to reduce night dew.
  

We certainly have plenty of things to do and to fix. There are also some problems we don't have solutions for quite yet. Any ideas welcome!

Summer Temperatures

A major concern of ours is internal dome temperatures. Right now we have a small ventilation system, but no cooling or heating system. Extreme temperatures will pose a problem because most UPS (uninterrupted power supplies) and computer systems are not designed to handle freezing or extreme heat.

On the left is a plot of our recorded temperature over a few months. The dome doesn't seem to be trapping heat or cooking our components yet. The dome currently houses an experimental computer with no special cooling and most of our required equipment (UPS, weather station, etc). So far the only casualty has been a remotely controlled power strip, but this is probably a defect and not a result of heat.

Basic Overview

The autonomous telescope we are constructing at Missouri State University (I'll call it "roboscope" for short) has a couple important goals. These include:

• User friendliness. Students should be able to schedule an observation as a part of classwork.
• Dependability/Autonomy. If you schedule something and the weather is good, you should have results as soon as you wake up the next day with no user intervention required.
• Modularity. Components should be easy to switch out. This is good for the long term operation as parts will inevitably wear out or become obsolete.
• Economics. Most telescope systems of this scale are out of reach for many schools because of cost. We aim to develop a system that other institutions can afford for themselves.

The hardest part about a project of this magnitude is stepping back and looking at all the components as a whole. This post is a sneak peek of some of the components making up our robotic observatory.

Prototype diagram

Our telescope system is composed of many parts. At the heart of it all is a computer running RTS2 software (among other things). This computer gathers information from a weather and temperature sensors and sends commands to hardware inside the dome. This includes dome motors, a telescope/mount, filterwheel, focuser, and ventilation. Not pictured in this diagram is surveillance and the security system protecting the equipment. Further posts will talk about each of these components in greater detail.

First Post

Just testing out the syntax highlighter...

#include <stdio.h>

int main(int,char**)
{
    printf("Hello, world!\n");
}