rewording some things

labs/lab-5.md

@@ -23,14 +23,16 @@ latex: true
 - [ ] 1 Breadboard
 - [ ] 1 GPS Module & Antenna
 - [ ] 1 Level-Shifter
-- [ ] Completed Circuit from Lab 3
+- [ ] Completed Circuit from Lab 3 and 4
 - [ ] Programming Cable (and adapters if necessary)
 - [ ] Computer with the Arduino IDE [installed](/tutorials#arduino-ide-install) and [setup](/tutorials#arduino-library)
 - [ ] ENGR100-950 Arduino Library (make sure this is updated!)
 
 ## Introduction
 
-Up until this point, you have been dealing with analog sensors - their only output is a continuous DC voltage that is related to the physical phenomena they measure. However, analog sensors are only a small subset of sensors that exist! In fact, this single output format is rather limiting - we can only express information about one specific parameter of interest. In previous labs, we used the Arduino to write lots of different types of information to the Serial monitor. That information was encoded as digital signals. Thus, we’ve transmitted digital signals in the past, but until today we haven’t needed to receive and interpret them. In this lab, we’ll use our first digital devices: the GPS module and the data logger. This GPS module communicates through the simple UART communications protocol. We’ll need the SoftwareSerial library, which will allow us to communicate with the GPS. In addition, the data logger communicates via a Serial Peripheral Interface (SPI). This is similar to the serial port, but slightly different. Luckily, the Arduino is set up to do this communication and header files allow us to use this functionality! The GPS doesn’t really ’measure’ any sort of physical quantity. Instead, it receives messages from satellites which are used to generate GPS information packets. These packets are continuously output by the GPS module, even when it doesn’t have a proper GPS fix. This sort of continuous output is called spewing. Having a GPS fix means the GPS is reasonably sure about your location on earth, with only a few meters total of potential error. The output of the GPS are formatted as NMEA strings. NMEA strings are simply a predictable way to format the location, altitude, and diagnostic stamps that the GPS provides into messages. These strings are identified by a 5 letter identifier. Here’s a list of all of them:
+Up until this point, you have been dealing with analog sensors - their only output is a continuous DC voltage that is related to the physical phenomena they measure. However, analog sensors are only a small subset of sensors that exist! In fact, this single output format is rather limiting - we can only express information about one specific parameter of interest. In previous labs, we used the Arduino to write lots of different types of information to the Serial monitor and the SD card. That information was encoded as digital signals. Thus, we’ve transmitted digital signals in the past, but until today we haven’t needed to receive and interpret them. In this lab, we’ll use our first digital devices: the GPS module and the data logger. This GPS module communicates through the simple UART communications protocol. We’ll need the SoftwareSerial library, which will allow us to communicate with the GPS. In addition, the data logger communicates via a Serial Peripheral Interface (SPI). This is similar to the serial port, but slightly different. Luckily, the Arduino is set up to do this communication and header files allow us to use this functionality!
+
+The GPS doesn’t really ’measure’ any sort of physical quantity. Instead, it receives messages from satellites which are used to generate GPS information packets. These packets are continuously output by the GPS module, even when it doesn’t have a proper GPS fix. This sort of continuous output is called spewing. Having a GPS fix means the GPS is reasonably sure about your location on Earth, with only a few meters total of potential error. The output of the GPS are formatted as NMEA strings. NMEA strings are simply a predictable way to format the location, altitude, and diagnostic stamps that the GPS provides into messages. These strings are identified by a 5 letter identifier. Here’s a list of all of them:
 
 [http://aprs.gids.nl/nmea/](http://aprs.gids.nl/nmea/)
 
@@ -44,13 +46,13 @@ IMPORTANT: We recommend saving intermediate Arduino codes, so that if something
 IMPORTANT: When we are dealing with serial communication and loading the Arduino with a lot of memory, which we are doing today, our Arduinos can sometimes ”freakout”, and become stuck. The way that we often solve this problem is to unplug the Arduino, and load the ”blink.ino” program into the Arduino IDE. We then plug in the Arduino and quickly try to load the blink code (make sure the right port is selected, since when you unplug and plug in the Arduino, your computer can change the port). This often stops the Arduino from misbehaving, and we can try to upload the other code.
 </div>
 
-![GPS Schematic](/media/gps-schematic-lab5.png)
+![GPS Schematic](/media/GPS-wiring-lab05.png)
 
 Schematic for the connections between the Arduino and GPS shown above.
 
 ## Level Shifter
 
-The GPS operates on a 3.3V voltage and sends the digital signals with a maximum voltage of 3.3V on its communication lines. Our Arduino, however, reads digital signals of either 0V or 5V. This means that we may not be able to read the 3.3V signals from the GPS, and thus we can’t communicate with it directly. We will use a logic Level-Shifter to convert from 3.3V to 5.0V. This Level-Shifter will take the digital 3.3V logic of the GPS and convert it into 5.0V logic of the Arduino (it can also do the reverse as well). The Level-Shifter is shown below. It is actually a generic device in that it can shift between two different arbitrary voltages. For our application, these voltages are 5.0V and 3.3V. In order to do this, we have to provide the level-shifter these voltages, therefore, it requires references to (read: electrical connections to) the two voltages that you’re trying to convert between – in our case, 5V on the high voltage (HV) pin, and 3.3V on the low voltage (LV) pin. Since there are two references, there are two grounds, one on either side of this device, that both need to be connected to Arduino ground.
+The GPS operates on a 3.3V voltage and sends the digital signals with a maximum voltage of 3.3V on its communication lines. Our Arduino, however, reads digital signals of either 0V or 5V. This means that we may not be able to read the 3.3V signals from the GPS, and thus we can’t communicate with it directly. We will use a logic Level-Shifter to convert from 3.3V to 5.0V. This Level-Shifter will take the digital 3.3V logic of the GPS and convert it into 5.0V logic of the Arduino (it can also do the reverse as well). The Level-Shifter is shown below. It is actually a generic device in that it can shift between two different arbitrary voltages. For our application, these voltages are 5.0V and 3.3V. In order to do this, we have to provide the level-shifter these voltages, therefore, it requires references to (read: electrical connections to) the two voltages that you’re trying to convert between – in our case, 5V on the high voltage (HV) pin, and 3.3V on the low voltage (LV) pin. Since there are two references, there are two grounds, one on either side of this device, that both need to be connected to ground.
 
 ![Level Shifter](/media/level-shifter-lab5.png)
 
@@ -60,11 +62,7 @@ Apart from the voltage references, there are the high and low voltage channels.
 
 ## Wiring and Testing GPS
 
-<div class="primer-spec-callout info" markdown="1">
-The wiring and code needed is covered in ‘Arduino Lab 5a: GPS Modules, Part 1’.
-</div>
-
-1. Connect the GPS to your Arduino, as described in the schematic above. You only need to connect to the GPS’s VIN (3.3V), GND, and TX pins. The GPS TX needs to go through the level-shifter, transfering from 3.3V TX on the GPS side to 5.0V RX on the Arduino side. Designate a port (D2) to take in data from the TX pin from the GPS. Remember that the TX pin an the GPS is the RX pin (D2) on the Arduino. We are not going to send messages to the GPS, so we don’t have to hook up the RX pin on the GPS, but it is good practice to ground this pin.
+1. Connect the GPS to your Arduino, as described in the schematic above. You only need to connect to the GPS’s VIN (3.3V or 5V), GND, and TX pins. The GPS TX needs to go through the level-shifter, transfering from 3.3V TX on the GPS side to 5.0V RX on the Arduino side. Designate a port (D2) to take in data from the TX pin from the GPS. Remember that the TX pin an the GPS is the RX pin (D2) on the Arduino. We are not going to send messages to the GPS, so we don’t have to hook up the RX pin on the GPS, but it is good practice to ground this pin.
 
 2. Test your wiring by creating a new Arduino sketch. We have supplied a sample code called read gps single character.ino. This code reads from your new Software- Serial port (D2) using the .read() function. If you aren’t familiar with the .read() function in the SoftwareSerial library, there’s a good reference for it here: https://www.arduino.cc/en/Serial/read.
 
@@ -81,8 +79,8 @@ The wiring and code needed is covered in ‘Arduino Lab 5a: GPS Modules, Part 1
     - A way to make sure you catch the gps when stuff is just being written to the buffer is doing a multi-stage check: (1) do a `while gps.available()` do `gps.read()` to clear the buffer and just ignore this data; (2) do a `while !gps.available()` do `delay(1)` to just wait until the buffer starts to get data again; (3) note the time using `millis` (print to the serial port); (4) do another `while gps.available()` loop where you read in the data into your c-character array, like:
     `i = 0;`
     `while (gps.available()) {`
-    `mystring[i] = gps.read();`
-    `i++; }`
+    `  mystring[i] = gps.read();`
+    `  i++; }`
 
     - For ease, the steps above are in a function, so you can call that and it reads in the gps data.
 
@@ -101,10 +99,15 @@ Go back outside with your board and collect some gps data. Walk around the perim
 Write a matlab (or python or whatever) code that will read your GPS data. Grab the lines that start with $GPGGA. Parse these lines so that you can get the time, latitude, and longitude. (If it is too difficult to figure out how to do this you can do this later...), simply copy and paste the $GPGGA lines into a new file so that all of the lines in the file have $GPGGA lines. You should then be able to read this into Matlab (or python) with a CSV reader.
 
 <div class="primer-spec-callout warning" markdown="1">
-Note: latitude and longitude are not exactly the right units - for now, just divide them by 100 and that will be close enough.
+Note: latitude and longitude are not exactly the right units. Technically, they are given as DDMM.MMMMM (for latitude) and DDDMM.MMMMM (for longitude), where D is degrees and M is minutes.  See question 4 below.
 </div>
 
-Using Matlab (or python), make a plot of latitude vs time, longitude vs time, and latitude vs longitude (3 plots total). **Submit these with your postlab.**
+Using Matlab (or python), make a plot of latitude vs time, longitude vs time, and latitude vs longitude (3 plots total).
+
+Take some of the latitude and longitude output from the GPS (at least 4 points) and manually put it into a google maps file as either lines or pins. Show these points on the google map and take a screenshot of this.
+
+
+**Submit these with your postlab.**
 
 ## Post Lab Questions
 
@@ -114,30 +117,30 @@ Using Matlab (or python), make a plot of latitude vs time, longitude vs time, an
 
 3. The Arduino has something known as a serial buffer. This buffer stores the bytes sent from the GPS (or whatever module you’re connected with) to the Arduino. It works like a circular buffer. Look up what a circular buffer is (Wikipedia is a great source here), and give a brief definition below (1-2 sentences).
 
-4. The GPS part hints that the latitude and/or longitude may not be in exactly degrees when divided by 100. Why might this not be the case (hint: think about how navigators sometime discuss locations in terms of degrees, minutes, and seconds)?
+4. The GPS part hints that the latitude and/or longitude may not be in exactly degrees when divided by 100. Why might this not be the case (hint: think about how navigators sometime discuss locations in terms of degrees, minutes, and seconds)?  How could you take the format as is (DDMM.MMMMM) and convert it to decimal degrees, which is what is needed.
 
 ### Point Breakdown & Summary
 
 This lab will be worth 20 points total in your grade and is graded as follows:
 
-1. Lab 4 Postlab: 15 points (Engineering, Team)
+1. Lab 5 Postlab: 17 points (Engineering, Team)
 
-2. Lab 4 Figures: 5 points (Technical Communication)
+2. Lab 5 Figures: 3 points (Technical Communication)
 
 ## Submission
 
 On Canvas, you will submit ***ONE PDF*** that will include all of the following:
 
-- [ ] All Arduino programs that were created for this lab (copy and paste into the PDF).
-- [ ] All GPS data (copy and paste into the PDF).
-- [ ] Plots of the GPS location information.
-- [ ] Answers to the post lab questions (as part of the .pdf file).
-- [ ] A screenshot of your Altium schematic (entire circuit from lab 3 + GPS and level shifter).
+- [ ] All Arduino programs that were created for this lab (copy and paste into the PDF) (1 pt)
+- [ ] All (or if you took a lot, then a subset of) GPS data (copy and paste into the PDF) (2 pts)
+- [ ] Plots of the GPS location information (3 pts)
+- [ ] Google Maps screenshot of the GPS location information (3 pts)
+- [ ] Answers to the post lab questions (as part of the .pdf file) (4 pts)
+- [ ] A screenshot of your Altium schematic (entire circuit from lab 3/4 + GPS and level shifter) (4 pts)
 
 **TECH COMM NOTES:**
 - [ ] Print your MATLAB or Python figures to png or pdf, do not use screencaps.
 - [ ] Include all necessary titles and axis labels.
-- [ ] Colors are your friend! Use them effectively.
 
 To put said content into a PDF, it is suggested you create a new Google Doc ([docs.new](https://docs.new)) and paste your images and write any text in the document. Export/Download this document as a PDF and upload it. **DO NOT SUBMIT A GOOGLE DOC FILE OR SPREADSHEET FILES.**