Week 18: Applications and Implications / Project Management¶

Linked mechanism¶

5-bar link Linked mechanism drawing a portrait

Assignment¶

Application and Implication¶

Plan a final project masterpiece that integrates the range of units covered, answering:
- What will it do?
- Who has done what beforehand?
- What sources will you use?
- What will you design?
- What materials and components will be used?
- Where will they come from?
- How much will they cost?
- What parts and systems will be made?
- What processes will be used?
- What questions need to be answered?
- How will it be evaluated?
Your project should incorporate
- 2D and 3D design,
- additive and subtractive fabrication processes,
- electronics design and production,
- embedded microcontroller design,
- interfacing,
- programming,
- system integration and packaging
Where possible, you should make rather than buy the parts of your project
Projects can be separate or joint, but they need to show individual mastery of the skills and be independently operable

Project Management¶

Prepare drafts of your final project summary slide (presentation.png, 1920x1080) and video clip (presentation.mp4, 1080p HTML5, < ~1 minute, < ~25 MB), put them in your root directory, and check that they are linked in the final presentation schedule

1. Plan a final project masterpiece that integrates the range of units covered, answering:¶

What will it do?¶

It is a portrait drawing robot. It is a robot that has a camera eye that can recognize human faces, a brain that converts the image into a line drawing, and hands that draw the image.

The robot idea

Who has done what beforehand?¶

There are a lot of SCARA-arm drawing robot examples, but I don’t see many that combine them with portrait drawing mechanisms.

Reference SCARA draw bot projects

What sources will you use?¶

Study the above examples, and ask ChatGPT about implementation ideas
Seeed Wiki, including ESP-DL, the deep-learning framework that works on the edge with a pre-built face recognition model
SCS0009 servo, FE-URT-1 board, and their manuals

What will you design?¶

System diagram linked mechanism

Software application for the portrait drawing pipeline
- camera
- Streaming on TFT LCD
- Switch to freeze a photo frame
- Face recognition from a photo
- Eye landmarks detection
- Edge extraction of the photo, with emphasis on the eyes
- Converting the edge image to a series of paths on an xy plane
- Conversion of the paths to servo angles for the right and left shoulders, and pen-up/pen-down motion
Electronic circuit
- Connect Xiao, TFT, and 3 serial servos
- Recreate and incorporate part of the FE-URT-1 dev board
Mechanism
- 5-bar linked mechanism
- Pen-up/pen-down mechanism
- Enclosure of the electronic parts

What materials and components will be used?¶

PETG/PLA 3D prints for the 5-bar mechanism and robot head parts
Electronic parts
- My original PCB board that incorporates the parts below
- Seeed Studio Xiao ESP32S3 Sense
- 1.8-inch SPI full-color TFT LCD
- Button switch
- 3 SCS0009 servos
- 6V adapter
- DC-DC converter from 6V to 5V
- Schottky barrier diode
- FE-URT-1 dev board or DIY version
  - PNP transistor
  - 2 x tri-state buffers
Wooden board to secure paper
Pen and paper

Where will they come from?¶

How much will they cost?¶

The following is a draft BOM for one complete robot. The custom PCB replaces the FE-URT-1 board in the final assembly; an FE-URT-1 can still be used during prototyping and debugging.

Category	Item / specification	Qty.	Made or bought	Source	Est. unit cost	Est. subtotal
Controller	Seeed Studio XIAO ESP32S3 Sense	1	Bought	Akizuki	¥2,660	¥2,660
Camera	OV3660 camera module with 75 mm cable (120°)	1	Bought	AliExpress	¥1,273	¥1,273
Display	1.8-inch SPI TFT LCD, ST7735S	1	Bought	Amazon Japan	¥899	¥899
User input	Momentary push button	1	Bought	Akizuki	¥90	¥90
Actuators	FeeTech SCS0009 serial bus servo	3	Bought	Akizuki	¥1,680	¥5,040
Power	Regulated 5V3A DC adapter	1	Bought	Akizuki	¥1,100	¥1,100
Electronics	Copper-clad PCB board	1	Made	Yodobashi	¥469	¥469
Electronics	Schottky Diode	1	Assembled	Akizuki	¥10	¥10
Electronics	Condensers　470μF	3	Assembled	Akizuki	¥10	¥30
Electronics	Condensers 0.1μF	3	Assembled	Akizuki	¥25	¥75
Electronics	0Ω jumper resistors	3	Assembled	Akizuki	¥1	¥3
Electronics	Pin socket	1 set	Assembled	Akizuki	¥80	¥80
Electronics	Pin header	1 set	Assembled	Akizuki	¥35	¥35
Electronics	wires	1 set	Assembled	Amazon	¥570	¥570
Electronics	Terminal Block (5mm)	1 set	Assembled	Akizuki	¥20	¥20
Electronics	heat-shrink tubing	1 set	Assembled	Akizuki	¥40	¥40
Mechanism and enclosure	PETG filament for the links, pen lift, body and head	Approx. 300 g	Made	Amazon	¥2,565	¥800
Hardware	Chicago Screws for linkage	1 set	Bought	Amazon Japan	¥1,627	¥1,627
Drawing surface	Wooden base board	3	Cut/engraved	Local dollar shop “Seria”	¥110	¥330
Consumables	Pen	1	Bought	Local stationery shop	¥100	¥100
Consumables	Drawing paper	1 pack	Bought	Local stationery shop	¥100	¥100
Development tool (not installed in the final robot)	FEETECH FE-URT-1 servo interface board	1	Bought	Akizuki	¥1,660	¥1,660
Development power supply (not installed in the final robot)	Regulated 6 V, 2.8 A DC adapter for the FE-URT-1 development setup	1	Bought	Akizuki	¥1,100	¥1,100
				Final robot total		¥15,351
				Total including development tools		¥18,111

The FE-URT-1 and its 6 V, 2.8 A adapter are used only to configure, test, and debug the serial servos; they are not installed in the final robot. The estimates exclude shipping and failed prototype parts.

What parts and systems will be made?¶

Milled PCB
portrait drawing pipeline software
5-bar link mechanism

What processes will be used?¶

additive fabrication process - 3D printing of the robot body
subtractive fabrication process - Laser engraving of the wooden board
Electronics design and production
Programming
Systems integration

What questions need to be answered?¶

Is there an OV3660 camera with a long cable that works with Xiao ESP32S3?
If it is not available in time, can I design a board that directly becomes the face of the robot?
❌ Does the SCS0009 servo move with only 5V input from Xiao?
❌ Does the FE-URT-1 dev board for SCS0009 work with only 5V input from Xiao?
Can I design and mill a serial signal converter board that can be an alternative to FE-URT-1?
Or is giving 6V to the servo and connecting it with Xiao’s TX enough to move the servos?
How can I improve the drawing quality of a 5-bar linked SCARA robot?

How will it be evaluated?¶

Cuteness of the robot
Quality of the portrait drawing

Reflections¶

Time is limited, and I have to focus on my final project....

Checklist¶

[X] What will it do?
[X] Who has done what beforehand?
[X] What sources will you use?
[X] What will you design?
[X] What materials and components will be used?
[X] Where will they come from?
[X] How much will they cost?
[X] What parts and systems will be made?
[X] What processes will be used?
[X] What questions need to be answered?
[X] How will it be evaluated?
[X] Uploaded summary slide (placeholder)
[X] Uploaded video clip (placeholder)
[X] Checked they are linked in the final presentation schedule

AI Usage¶

I used Codex for grammar checking, and made the final review.

Sources¶

References are in the above “Who has done what beforehand?” section.