Sensor board schematic peer review

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    sensorboard_kerbs = str(SENSORBOARD_REVIEWS[cs_username])[1:-1]

KeyError: 'None'

Learning objectives

In ex01 we captured the schematic of a circuit for sensing temperature, relative humidity, and light level.

Before we go on to layout, we want to make sure the schematic is functional. So every student is going to review 3 other students' designs. This does two things:

• You'll get to see how other students do their designs, which might inspire or influence you.
• You'll decrease the likelihood that your design is not functional.

Timelines

We have limited time for design reviews because we need to get on to layout.

You'll be assigned the three student designs Monday evening. Your reviews are due Thursday 5pm.

Getting your peer designs

We've randomly assigned you to review 3 other designs. You've been assigned the schematics of: <div><font color='red'><b>A Python Error Occurred:</b><p>

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    print('%s' % (sensorboard_kerbs,))

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1. Clone the repos. They will have very similar format to your repo. Open a terminal window. Navigate to the directory where you'd like to store these repos. Then clone:

git clone git@github.mit.edu:6-900-S25/sensorboard-[kerberos].git

where [kerberos] should be replaced by the name of each student's project that you are assigned to. You'll clone 3 different repos.

1. Open the project. From the KiCad main window, hit File->Open Project, navigate to the repo and select the *.kicad_pro file.

1. Open the schematic. From the KiCad main window, you should now see the *.kicad_pcb and *.kicad_sch files. Double-click the schematic file to open it.

If that all works you should now see your peer's design.

Doing your review

We're going to do the peer review as a markdown file. Markdown is a simple way of getting basic formatting in a text file. You can see the main commands here though many other guides also exist.

1. Open up your favorite text editor.
2. Create a blank markdown file in the main folder of the design you are reviewing. Name it None-schematic-review.md. Save it.

Your folder should now look like this:

1. In your text editor, add two lines:

## Function

## Style

You're going to give feedback about the function of the design, aka does it work, and feedback about the style of the design, aka is it easy to read and understand.

Function

Here you're trying to figure out if there are any errors in the design that will prevent it from working.

Some checks to make (not an exhaustive list!):

• Both ICs present and the correct part numbers.
• Power and ground pins of each IC connected to +3V3 and GND nets (or similarly labeled nets).
• Two -- and only two -- pull-up resistors on the SDA & SCL lines, each 4.7k
• One LED with a resistor connected in series. Don't worry about the resistor value, though it ideally be in the 100's of Ohm range.
• Two 2x2 connectors of the right part number
• One connector should have connections to GND, SCA, and SCL.
• One connector should have connections to GND and 3V3.
• At least four testpoints, one each for 3V3, GND, SDA, SCL.
• All components have footprints assigned and the correct ones.
  • Rs, Cs, and LED have 0805 footprint.
  • Connectors: Connector_PinHeader_2.54mm:PinHeader_2x02_P2.54mm_Vertical
  • SHT4x: Sensor_Humidity:Sensirion_DFN-4_1.5x1.5mm_P0.8mm_SHT4x_NoCentralPad
  • VEML7700-TT: should have a footprint associated with it, though the name will depend on which library it was acquired from
  • Testpoints: TestPoint:TestPoint_THTPad_2.0x2.0mm_Drill1.0mm
• Running ERC returns no errors beyond "Input power pin not driven by any Output Power pins"

Note that this isn't a complete list. Use your judgement if you see any other issues!

If you find an error, add a line to the Function section, explaining the issue and being as specific as possible. For example:

## Function

* C1 and C2 are not connected to ground
* Missing testpoint on SDA net

## Style

If the design has no functional issues, write that:

## Function

* No issues

## Style

Style

Here you're trying to give feedback to make the design easier to understand for others, since one role of a schematic is to communicate with humans.

Some checks to make (not an exhaustive list!):

• Parts and their text are not overlapping
• Use of net labels for SDA, SCL, 3V3, GND
• Label connectors with a name that makes sense, like power, or I2C

If you find a style issue, add a line to the Style section, explaining the issue and being as specific as possible. For example:

## Function


## Style

* R1 and R2 are overlapping

If the design has no style issues, write that:

## Function


## Style

* No issues

Finish and submit your review

1. When you're finished with your review, save your markdown file.

2. Then stage, commit, and push the review.

git add None-schematic-review.md

git commit -m 'peer review by [your kerberos]'

git push origin main

Close out of the schematic files. If prompted do not save any changes to the schematic file.