The reciever box

This is a picture dump of the receiver box we made, this circuit takes in and essentially scrubs a signal to make it much easier to collect useful data.  Making this complete circuit took about two weeks, using an MIT write up for directions and schematics.  We first laid out all of the parts to form the circuit before we connected everything, this helped us visualize it and make sure we had each part so we could build the complete circuit. We ran into a few hiccups while soldering simply due to human error.

PRMS reading an angle in Simulink

7/14/17

The final working simulink code and function within is shown above. In conjunction with PRMS (Pasco Rotary Motion Sensor) we are able to tell what angle the Viper Radio telescope is pointed at...

Some important notes:

-DO NOT have anything uploaded to your arduino or have anything open that could block simulink from connecting to the port.

-DO NOT locate which serial port you are using by looking at the Arduino IDE... it may be wrong... instead enter 'cd /dev/ ' into the terminal, then type 'ls',  then remove your usb, then type 'ls' again to see which one from the list is there when you have the usb plugged in and not there when the usb is unplugged. Should be located below the bluetooth stuff. Enter this into Host-board connection port number for a proper connection. It was '/dev/tty.usb.modem1411' for me.

-The sample time inside the two digital input pins is set to 0.0001. If we go to 0.00001 simulink will be too slow to be anywhere near accurate. However, 0.0001 is still too small of a sampling time to get a perfect reading, but it is the best we can do for right now... a sampling time of 0.000025 is the eventual goal. Uncertain if this is a simulink limitation or a limitation of the computer I am using.

-You must set the serial 0 baud rate to 115200 inside of this menu shown below... click the gear looking icon at the top of simulink to get there.

week 5 day 3

we managed to install the second wheel today as well as the outside face of the center wheel on top of getting the wheels set in the right place  

Week 5 day 2

today we were able to install the right wheel with little resistance as you can see in the picture we had to saw a hole in the floor to be able to set the plate and the wheel in their correct spots.  this is because the wheel was pushing up against the wood beam at its thickest point.

Second Week

Completing the Receiver Box-

Most the parts that we ordered were in by the Tuesday of this week allowing for the final construction of the receiver to commence. Aside from some misaligned holes, construction of the final product went relatively smoothly. Self tapping screws were required to secure the lid on the box, since the use of nuts allowed for the screws to freely slip in the pre-drilled holes. Prior to testing the box, the computer with which the Viper telescope data is located encountered an error that did not allow for the system to boot up. The issue was found to be the fact Kernel had been corrupted on the system, and it had to be reinstalled. There is a program in the SRT folder on the computer that allows for the measurement of incoming frequencies and save them to a file to be observed later. Upon testing the box against the results of the USB device which served the same purpose, we found the box to be faulty so we looked to find what could be a source of error. We still got a signal through both, however, the box did not allow for the expected shift when radio waves are directed at the dish. We also wen through multiple cables to see if the fault lied in the transmission of the signal. Upon getting the voltage across the V+ and ground, we found that is was upwards of 36 Volts in AC and nearly zero in DC. We expected that value to be around 15 Volts. We didn't really have a way to see what was wrong in the box since it was sealed, and there weren't any clear indications as to what the cause of the issue was, so the conclusion was a faulty power box. Once the box was removed, some of the soldered connections on the board had to be redone. Dr. McColgan suggested that we find the difference in a transistor that has DC running through it, and that which has AC. In the protoboard we used, the function generator was broken, and we went through 3 different function generators to get a signal into the breadboard, however, we were unsuccessful in viewing a clear distinction.

First Week

The members of this project are as follows:
Nico Carello- nj09care@siena.edu
Krista Plouman- km27plou@siena.edu
Brandon Watt- ba10watt@siena.edu
Timothy Ladeairous- tj29lade@siena.edu
Josh Hayes- jt28haye@siena.edu

This week we were tasked with creating the Receiver Box, 90° Combiner, High Pass Filter, and working on the code 

Brandon and Josh completed the 90 Combiner and the High Pass Filter. This was completed using pages 16-22 of the SRT Hardware Manual by Dustin Johnson. It was relatively straightforward to construct since all the pieces were pre-ordered and the instructions were relatively clear. The hardest part had to be the cutting of the circuit board since we could only utilize only a quarter of the full sheet for what was needed and the board itself was quite easy to break. Also, since the printout was in black and white, it was tough to figure out which wires the instructions were referencing when they referred to colors. This was resolved by pulling up the pdf which had the instructions in color. In doing this, it also helped with the construction of the receiver board which was also color coded. 

FIG 1: The Solder Master (Self Titled) himself.

FIG 2: Earliest stages of the board with the 90° Combiner on the plate.

Krista and Nico worked on the code that was created by Jon Farrel in the year prior. Their work can be seen by posts they published on the Blogger page.

Tim worked on drilling holes in the Receiver board to bolt down all the components. The instructions for this work can be found on pages 24-29 in the SRT Hardware Manual by Dustin Johnson. It took 2 days to get all the holes measured and drilled into the board. The instructions called for laser precision which we could not achieve here on campus. Also, once the holes were drilled, we outlined where each part and connection would go and realized we were missing a connection between the first IF Amp and the 7MHz filter. We also tried to color code our wires as best we could, making orange ground, red 15 volts, blue 12 volts, and yellow 5 volts. Upon actually beginning to bolt components down, it was decided that longer screws would be desirable as the shorter screws would make some connections very difficult to complete. Connections with more than 2 pieces proved to be very troublesome, with the solder not being able to bind the wires. Shrink tubing was used to cover connections that ran the risk of interacting with other connections close by in order to prevent a short circuit from damaging the board. A larger holding box would have been desirable if it were possible to attain since the current box seems to be a tight for all the different components. The bits used to drill the holes were 7/64 and 5/32. 

FIG 3: This is the circuit diagram created by MIT color coded to match the wires we were using. With key components circled that had different voltage wires being run through them.

FIG 4: This is roughly the completed board, with nearly all the wiring completed, barring the few pieces were waiting to come in and the components not being bolted in.

The group learned the purpose of a bias tee. It acts as a filter for DC and AC, where AC is allowed through the capacitor while DC is allowed through the inductor. 

FIG 5: A simple diagram of how a bias tee works.

Notes on Haystack SRT codes from Bennington College

Bennington has made some very thorough notes on using the SRT :
https://github.com/BenningtonCS/Telescope-2014/wiki/Installing,-Compiling,-and-Running-MIT-Haystack-SRT-Code