EECS16A - Lab Equipment Overview
This guide serves as a reference for students in EECS 16A lab to familiarize themselves with the equipment present in the lab. Read carefully so you do not accidentally damage the equipment and potentially hurt yourself.
Create an EE16A account by logging into acropolis with our CalNet ID. Click “Create an Account” for EE16A and wait for the page to create an account. You will be presented with an ee16a account and a password and prompted with an option to send the account information to an email. Please email this account information to yourself. Use the account credentials to log into a lab computer.
USB - There are USB ports on the front panel of the computers for you to use during the lab. However, due to extended use, some of the USB ports may not work 100% of the time. If one port does not work, try switching to a different one.
Audio - There are two audio jacks on the computer - one microphone and one headphone. Each have a symbol on top of the jack to indicate which one they are. Make sure that your equipment is fully pushed into the jack and test before using the ports.
GPU - Each computer is outfitted with a Graphics Processing Unit (GPU) to drive the monitors. In the imaging module, we make use of the HDMI port on the GPUs to connect our computers to handheld projectors - the HDMI cable must be plugged into the GPU as opposed to the motherboard to function correctly. You should not need to be unplugging and plugging in cables to the lab benches.
Installing Software - We have restricted access to most of the C:// drive on the Windows machines to prevent tampering with the installed software. We carefully select packages and versions to ensure a smooth lab experience - please do not install different versions of software to avoid breaking any dependencies. As a user, you have full access to the Downloads folder, so please use that folder for all your lab needs.
Syncing Files - The U:// drive is where you can store files in the University’s cloud space if you need to access files across computers.
On a Windows computer, you can change your password by hitting Control + Alt + Delete and selecting “Change Password”. Follow the prompt to permanently change your password. If you ever forget the password that you set, you can reset it by going to acropolis and resetting the password associated with that account.
To download the lab, go to the class website and download the lab to your Downloads folder. All the labs come zipped in a compressed archive format and need to be uncompressed. To do this, open the file explorer, go to the Downloads folder, right click the lab zip file, and extract all. Every lab include a BAT file (batch script) that will help you launch the lab. Double click “Launch Notebook.BAT” to execute the script to open the lab notebook - if there is a popup “How do you want to open this file?”, close the dialog to continue running the script. If there is a pop up that says “Untrusted Source”, click “More Options” and hit “Run Anyway”. If there is a popup that says “Search for app in the Store?” hit No to continue running the script.
Handling Instructions - The MSP comes in an anti-static bag to protect it; you can keep it in this bag if you want to keep it extra safe, but keeping it in the box is also fine. As with all electronics, do not expose it to water and be gentle with it. Do not change the circuit while the MSP is connected to while plugged into the computer. This can potentially permanently damage the MSP to the point where it may not function.
Connecting to the computer - Use a micro-USB to USB cable to connect the MSP to the lab station. You should see a Green LED light up near the micro-USB port to indicate that it is working. Next, you want to figure out what COM port the MSP was assigned. To do this, hit the Windows Key, then type “Device Manager” and select that option. A small warning will pop up - hit OK to continue. Once at the Device Manager window, open up Ports and you should see 2 or more devices connected. Of them, two will correspond to the MSP - one is the debugging interface and the other is the UART interface. The COM port we care about is the UART interface - take note of what COM port it is.
Energia - Energia is the software TI has provided us to interface with the MSP. It is built off of the more well known IDE, Arduino, and allows us to program the MSP, as well as read data off of it. To launch it, go to your desktop and double click the Energia icon.
Uploading Code - To upload code, you must first go to Tools > Ports > COM #, where # is the COM port number you found in the “Connecting to the Computer” section above. With that selected, you can load in the code by going to File > Open and finding the file for the lab. Now that Energia is setup to upload code, you can hit the right arrow button to upload the code. Watch the logs on the bottom of the window to make sure it completes. Once it is done hit the RESET button on the MSP.
Serial Communication - There will be points in the lab where it asks you to open up the Serial Monitor. This is how we get data from the MSP. However, there are a few rules that the Serial Monitor needs to abide by in order for us to visualize the data properly. Firstly, there can only be one Serial Port open per device on a computers - if you try to open multiple instances of Serial to communicate to the MSP, only the first one will work. Secondly, Serial needs to agree on a speed for it to communicate. Make sure you are selecting the correct Baud Rate for each lab (can be found within each lab) and setting that in the Serial Monitor menu.
Breadboard - Used to make circuits.
Jumper Wires - Nicely packaged wires to connect your breadboard to peripherals - very useful when prototyping or making small circuits. Make sure to tear apart your jumper wires before using them (similar to string cheese before eating). There are three different configurations - Male to Female, Male to Male, Female to Female. Pay close attention to what your circuit requires when choosing a jumper wire. Jumper wires are not to be confused to breadboarding wires. Breadboarding wires are not in your kit and can be used to create cleaner breadboards by cutting and stripping to required lengths. Do not cut or strip your jumper wires.
Op Amp - You will learn more about what an Op Amp is used for later in the course. It can be used in many different circuit configurations for a variety of analog and digital applications. This particular Op Amp (LMC6483) has two Op Amp circuits in it.
LEDs - Light Emitting Diodes are special circuit elements that only conduct unidirectionally, i.e. they are polarized. If there is enough voltage across the LED and minimal current is supplied, it will emit light. The Longer Leg is Positive, and the Shorter Leg is Negative.
Ambient Light Sensor - A sensor that changes electrical properties based on the amount of light present. We will be using the Ambient Light Sensor (ALS) to create our imaging system. Thought it shares a resemblance with the LED, the polarization is the opposite: Shorter Leg is Positive, and the Longer Leg is Negative.
Gauge - The breadboarding wires we use in the lab are 22 gauge (0.65mm), so you will need to use that slot to strip these wires. You can read about the sizing here where it explains the wire size as well as how much current can be sourced through them.
Stripping Breadboarding Wires - Breadboarding wires come with a layer of insulation that needs to be stripped away before using with a breadboard or soldering. To strip a wire, you must first identify which wire gauge you would like to strip to, and place the wire in the selection. You typically only need to strip off a centimeter (shorter length of your pinky nail) to get it to work with your breadboard. For a video demo, watch this video.
Cutting - The wire stripper is also outfitted with a wire cutter close to the fulcrum. This will be useful when cutting wires to the correct length while breadboarding.
Keeping your breadboard circuit planar - In EECS16A, we enforce a planar breadboarding rule. This means that your breadboard cannot have wires in long loops above your breadboard. The wires in your circuit should be cut to the appropriate length so the breadboard looks clean and organized. Here are a few tips and tricks to get you started on planar breadboarding.
The Precision Wire Cutter, or Diagonal Angle Cutters are to be used and left at the TA desk. When using them, please cut over a trash can or the scraps box on the TA desk to avoid making a mess.
Soldering Irons can burn you - they heat up to temperatures well over 300oF. This comes alongside with the fact that they can easily be damaged. To ensure your safety and the longevity of our equipment, please read this entire section very carefully.
Before starting to solder, you must take the soldering iron stand to the TA desk to wet the sponge. There should be a water bottle at the TA to help you with this. The wet sponge serves as a safe way to clean the tip of the iron.
Solder can be obtained at the TA desk in small snippets. You will typically only need half a foot of solder for each soldering lab. They can be cut with scissors or wire cutters at the TA desk.
You might want to use the clamp to secure your Printed Circuit Board (PCB) while you solder. Adjust the width of the clamp by turning the knobs on the side. If your station is not fitted with a clamp, you will have to solder on top of the mat.
The tip tinner is used to keep the tip of the soldering iron healthy. If the iron is exposed to the air for too long while hot, oxidation reaction takes place much faster and starts to turn into iron oxide which cannot be used for soldering. To prevent this, we coat the tip with a layer of solder using the tinner. You can ask a Lab ASE or TA to do this for you.
The soldering iron tip is copper coated with a thin layer of iron. If the tip somehow gets damaged (through chemical or physical damage), the copper inner core can get exposed, destroyed the iron altogether. To prevent this, always make sure your tip is tinned and to turn off the iron when not in use. Chemical damage is how most of our irons get ruined, thanks to how quickly the tip can oxidize when at 400oC. Please help us keep our equipment operational.
The PSU is used to power our circuits. It comes with three different configurable channels as well as a safety current limiting feature.
There are two types of cables or leads in the lab - Alligator and Hook leads. They both can serve the same purpose, and the choice to use whichever is purely personal taste. They are terminated by a banana plug that goes into the PSU. Both come in Red and Black variants - by convention, Red is used for non-ground and Black is used for Ground.
To connect them to your breadboard, you must attach a wire that will act as a medium between either the alligator clip or the hook to the breadboard. Make sure that the alligator clip clamps down on exposed copper from a breadboarding wire by pinching the side of the clip to open and feeding a copper wire between the teeth. The hook comes out by pushing down on the base of the housing like a syringe to expose the hook that can clamp down on a piece of exposed copper.
The PSU’s in lab have 3 channels: +6V, +25V, and -25V. They each are named after their upper limit in voltage magnitude they can supply - i.e. +6V can supply up to 6V, +25V can supply up to 25V, and -25V can supply down to -25V. The +6V rail is special due to it also being able to supply higher current, up to 5A. This will never be of use in this lab, as we ask everyone to limit the currents for all channels to 0.1A (See Current Limiting). The PSU creates the potential set by the user between the red and black terminal, labeled in the figure below (Note on the -25V rail: If the PSU is outputting -25V on its channel, that means the black terminal is 0V and the red is -25V). Remember that the black terminals are all ground and should be connected somewhere on your circuit.
While the black probes are considered to be “ground”, there another type of ground that is available on the PSU. The green probe in the middle is Earth ground, which means it is literally connected to the earth through the power cable connected to the PSU. It is not necessary to use the Earth ground. Because there are many grounds coming from the PSU, we need to make sure that they are all connected. A common way to do this is to connect both of the black terminals from the PSU to the same wire and then to the ground rail on the breadboard.
Current limiting is a safety feature of the PSU and must be performed every use. Each channel has its own current limit, and must be set before using. To set the current limit for a channel, first select the channel by pressing the button corresponding to the channel you would like to use, and press “Current Limit”. This will bring up a menu with a blinking cursor that shows the current and voltage limits for that channel. We do not care to set voltage limits, so we will focus only on the current limiting. If the blinking cursor is on the Voltage side (left side), hit the big button under the knob that says “Current | Voltage” to swap over to the current side. Use the knob and arrow keys to adjust the current limit to 0.1A and do this for all channels you plan to use.
Similar to the power supply leads, there are two types of multimeter leads - alligator and hook. They are used in exactly the same way - please refer to the above Power Supply “Types of cables/leads” section. The difference between the power supply cables and the multimeter cables is the termination. Power supply cables end in a banana connector that has exposed metal, but the multimeter cables have sheathed connections. Refer to the picture below to identify the difference between power supply cables and multimeter cables. Some of the multimeter cables have right angle connections - those are fine as well.
The multimeter can measure various electrical characteristics - some of which are special and require a different probe setup to work, so pay close attention.
Mode 1 - Measures a stable voltage on your circuit. To measure voltage, you must put the black probe to ground and the red probe to the voltage you would like to measure - in other words, you will be placing the probes in parallel with your circuit.
Mode 2 - Measures a stable current through your circuit. The measure current, you must make sure that the probes are in mode 2 and that the current you would like to measure is goes into the red probe and out of the black probe. Your circuit should not function correctly. without your probes, as the probes are functioning as a wire that completes the circuit.
Mode 1 - Measures resistance between the probes. It will not just look at what is visually between the probes, but also all parallel resistances measured as an equivalent resistance. You should be able to verify the resistance measurement for known resistance networks using equivalent resistor network models.
Mode 1- Measures the capacitance between the probes. Similar to the ohmmeter, it measures all capacitances between the probes, including the capacitances that are not visible (parasitic capacitances).
Each meter has a tunable range - a maximum and minimum that it can measure. You can adjust this range by pressing the up and down arrows in the middle of the multimeter. A bigger range means it can measure higher values, but will lose resolution for smaller measurements - a smaller range means it can measure very small changes (i.e. a high resolution) but will saturate (represented by 0L being displayed) if the measurement is too big. The following is a measurement taking 5V at various ranges.
WARNING - The tips that should be on your oscilloscope probes can come off - do not lose them. These cables are very expensive and fragile, and need to be maintained well to be operational.
How to Insert - The Spring Loaded Clip (similar to the hook lead for the PSU) is the side that measures signals, and the alligator clip is used for a ground reference. The otherside goes to the oscilloscope - hold the round free turning part of the probe and gently push and turn clockwise to insert into the scope.
Testing - Before using the probe and the oscilloscope, you will want to make sure that your probe is operation. While we do regular upkeep of the probes, there is still a chance that someone in one of the previous labs had messed with the probe. Turn the oscilloscope on (button at the bottom left corner). Connect the probe to one of the 4 input channels (yellow, green, blue, or red). Make sure that the channel is on (indicated by a green light on the channel number). To turn a channel on (when it was originally off), simply press the corresponding numbered button. To turn it off, push the button again, and the light will be off. To test the probe, first locate the 3 metal testing tabs to the left of the 1st input channel (pictured below). Connect the black alligator clip of the probe to the middle (horizontal) tab. Connect the spring loaded clip end (or just the probe tip if your probe lacks a shell) to the left-most tab (vertical). With the probe connected, hit the "Auto Scale" button at the top right (pictured below). If your output is a square wave (pictured below), then your probe is working. If your output is not a square wave, tell your GSI immediately. See the figure below for the buttons and what the waveform should look like.
After probing, follow the guide below to learn how to adjust the window of the oscilloscope to see watch your signal.
If the screen says "Remote" on the right side of the screen, press the "Graph/Local" button above the on/off button. The remote symbol on the right side of the screen should now be replaced with a sine wave. Once you have the sine wave on the right side of the screen, you're good to go. (FYI, this step allows us to control the tool with the buttons on the front, rather than a remote control like the computer)
How to plug it in - The function generator cable plugs into the “Output” port on the device. Similar to how the oscilloscope probe plugs in, gently push the cable in while turning clockwise to plug in. The black part of the cable should go to ground. The “Sync” port is used when you want to use multiple Function Generators and make sure that their time references are in sync. We will never use this feature in this class, so you should never be using the “Sync” port.
50 Ohm - The function generator expected the circuit to be 50 Ohms of loading resistance. The reasoning as to why this is the case is rather complicated, so we will not go over that (check this link for more info), but we are required to design our circuit such that it is roughly 50 Ohms of loading resistance, or else the amplitude of the output coming from the function generator will not be correct.