RaspberryPi Robot Project

Technologies:

Render:

intent

Currently designed to act as programmable sentry.

🔹 control	: RPI_0w using NodeJs server to access GPIO Python code
🔹 movement	: 4 MG995 Servos, 2 subMicro Grippers & HS55 Servos, PCA9685 I2C Controller
🔹 sensing	: RPI 2.1 Camera, Insiq Bluetooth Speaker, Microphone MI-305
🔹 travel	: Tamiya Track, Double Gearbox, 2 F130 DC Motors, L293D
🔹 added	: 10 mm color LED, USB mini microphone
🔹 power	: rechargeable TL-PB 10400 & TL-PB 5200 mAh Powerbanks

Explores various inexpensive bare metal programming technologies. Future possibilities:

▶️ completion of the I2C servo operation
▶️ VAC (Voice Activated Commands) for more autonomous response
▶️ simple AI NLP for generalized communication
▶️ ESA AstroPi SenseHat for environment detection

The descriptions below show the most recent developments first.

robot 3 / added Servo armature

• servos: (4) Servo Motor, PN: MG995
• control: PCA9685 16 Channel 12-Bit PWM Servo Motor Driver
• speaker: USB Bluetooth Speaker Insiq PN: 4326595940 🔹 (upgrades BT3500SLV)
• servos: (2) Hitec subMicro Servo motor, PN: HS55 🔹 (upgrades HS300)
• grippers: (2) Actobotics subMicro Gripper Kit, PN: 637104 🔹 (upgrades "A" Grippers)
• steppers: (4) Stepper Motor 28BYJ48 🔸 (later removed)
• control: (4) ULN2003 Driver Board 🔸 (later removed)

The SketchUp 3D drawing required only new Flange & Gripper drawings.
All the other components were accessible online.

Originally, the Steppers were used because they had an optimal fit & flexibility.
However, they were not scalable; there were too many GPIO leads needed.
A RPI 40 pin J8 form factor required a different addressing solution.
Note that some websites suggest RPI timing is not reliable enough many protocol calls.

robot 2 / added camera, grippers

• camera: RPi Camera v2.1 with 8 Megapixel & 1080p resolution, PN: 2.1
• speaker: GearHead Bluetooth Speaker, PN: BT3500SLV
• microphone: USB mini microphone, PN: MI-305
• light: 10 mm color LED
• battery: TPLink PowerBank 10400 mAh, PN: TP-PB10400 🔹 (upgrades 4 AA batteries)
• grippers: (2) Actobotics Horizontal Gripper Kit "A", PN: 637094
• servos: (2) HiTec Servo motor, PN: HS300, with C24T or H25T spline

The Grippers and Speaker worked, but proved to be clunky.

The LibreCad 2D CAD representation with BOM.

robot 1 / travel control via SmartPhone

• computer: RPi0WF 1.1 SOC with BCM2835 cpu
• control: L293D Controller DriveShield
• gearbox: Tamiya Double Motorized Gearbox, PN: 70168 with (2) F130 DC Motors
• chassis: Tamiya Tracked Vehicle Chassis, PN: 70108-1500
• battery: TPLink PowerBank 5200 mAh, PN: TP-PB5200 (for RPi)
• battery: (4) AA batteries in case (for motors)

The RPi operates the L293D thru GPIO ports using Python PWM code signaled by a NodeJS server.

software

os base: Raspbian, Bash, Putty, WinSCP, GitHub...
control: Python & IDLE for DC motor PWM control
server: NodeJS, Express, (JavaScript, HTML, CSS) for view
drawing: LibreCad 2D CAD, Sketchup 3D

The L293D Controller pinout diagram.

xtra

github image viewer
stackoverflow github html discussion

HTML5 text folding
CSS&JS folding

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