Hardware Components for Building Scignos Robot
The following hardware components (with their price tag) were used to build the Robot.
1) Raspberry Pi - The Version used in the examples found on this Site is a Raspberry Pi 1 Model B+ Revision 1.2. This is the only Model which has been tested.
It may be difficult to find this specific Model. Nonetheless, the Raspberry Pi 2 Model B can be purchased, and the ServoBlaster library has been updated for this Model, according to the ServoBlaster Site https://github.com/richardghirst/PiBits/tree/master/ServoBlaster.
The latest Raspberry Pi Model (Pi 3 Model B) can be purchased, but there is no confirmation on the ServoBlaster Site that the Library is compatible with this Model. Perhaps someone has tested this.
The specifications for the Raspberry Pi 2 Model B are the following: Broadcom BCM2837 64Bit Quad Core Processor powered Single Board Computer running at 900MHz, 1GB SDRAM @ 400 MHz, Micro SD, 4x USB Ports, 40 GPIO Pins, 1.8A @ 5v.
This Model retails for $35.00
2) USB WiFi Dongle for Raspberry Pi, retailing for less than $10.00.
3) Mini Speaker. The speaker used in the examples found on this Site is The Pi Hut Portable Speaker, which was purchased for approximately $15.00 (�12.00). This speaker is of good quality. Meanwhile, it is a little large (and heavy). Because of its size, the 3d Printed head of the Robot, which contains both the speaker sitting on top of the head Servo, had to be made slightly larger than what it should have been, in proportion to the rest of the body. Some smaller and lighter (and cheaper) alternatives exist, which can be purchased on ebay.
4) The Microphone used in the examples found on this Site is a Mini USB Mic which was purchased for $3.00 from Amazon at the following Page: https://www.amazon.com/dp/B00MP42Y44/ref=pe_385040_30332190_TE_3p_dp_1
This microphone is currently unavailable, and it is not clear if it will become available in the future. Also, this microphone is fairly large, and it appears that there are not too many USB Mic alternatives available on the market. Perhaps someone might have a better model.
5) The 17 Servo Motors used for building the Robot are the TowerPro MG996R Servo. They were purchased on eBay for $5.18 per servo, for a total of $88.06 (with free shipping). There are several vendors on eBay offering this Servo (the cheapest being from China).
Here are the Servo specifications according to the Datasheet:
High Torque Metal Gear Dual Ball Bearing Servo
This High-Torque MG996R Digital Servo features metal gearing resulting in extra high 10kg stalling torque. The MG996R is essentially an upgraded version of the famous MG995 servo, and features upgraded shock-proofing and a redesigned PCB and IC control system that make it much more accurate than its predecessor. The gearing and motor have also been upgraded to improve dead bandwith and centering. The unit comes complete with 30cm wire and 3 pin 'S' type female header connector that fits most receivers, including Futaba, JR, GWS, Cirrus, Blue Bird, Blue Arrow, Corona, Berg, Spektrum and Hitec.
This high-torque standard servo can rotate approximately 120 degrees (60 in each direction). You can use any servo code, hardware or library to control these servos, so it's great for beginners who want to make stuff move without building a motor controller with feedback & gear box, especially since it will fit in small places. The MG996R Metal Gear Servo also comes with a selection of arms and hardware.
� Weight: 55 g
� Dimension: 40.7 x 19.7 x 42.9 mm approx.
� Stall torque: 9.4 kgf�cm (4.8 V ), 11 kgf�cm (6 V)
� Operating speed: 0.17 s/60� (4.8 V), 0.14 s/60� (6 V)
� Operating voltage: 4.8 V a 7.2 V
� Running Current 500 mA � 900 mA (6V)
� Stall Current 2.5 A (6V)
� Dead band width: 5 �s
� Stable and shock proof double ball bearing design
� Temperature range: 0�C -55�C
6) The Servo Brackets used were purchased as a 17DOF Biped Robotic Educational Robot Humanoid Robot Kit Servo Bracket. They were purchased on eBay for $64.92 + $10.00 Standard International Shipping, for a total price of $74.92. There are several vendors on eBay offering this Package (the cheapest being from China).
The specifications of the Package are the following:
17DOF Biped Robotic Educational Robot Humanoid Robot Kit Servo Bracket
Features:
- Humanoid robot
- Color: Black
- Size:40cm(H)*23cm(W)
Containing the 17DOF:
1DOF of the head
4DOF of the arm
2DOF of the shoulder
2DOF of the hip
6DOF of the legs
2DOF of the feet
The robot can mount 17 servos.
Package includes:
- 16 x Multi-functional servo bracket
- 7 x Short U-type servo bracket
- 4 x Long U-type servo bracket
- 4 x Oblique U-type servo bracket
- 4 x one-type servo bracket
- 4 x L-type servo bracket
- 1 x U-type robot waist bracket
- 2 x Foot Base
- 14 x Miniature Ball Radial Bearing
- 17 x Metal Servo Horn
- 1 x Screw and screw cap set
7) The 3D Printed Parts, consisting of the parts hereafter were printed at a municipal library for a cost of approximately $30.00.
- 2 Feet
- Front-Body Part
- Back-Body Part
- Front Head Part
- Back Head Part
- 2 Shoulders
8) The Raspberry Pi is powered by its own 5 Volt, 5200mAh Battery Pack. Its consist of the Anker Astro E1 5200mAh Ultra Compact Portable Charger (External Battery Power Bank) with High-Speed Charging PowerIQ Technology (Black), purchased from Amazon at a price of $20.00, but can now be purchased directly from Anker�s Site for $15.99 (https://www.anker.com/products/A1211012). The Micro USB Cable required for powering the Raspberry Pi is included with the Battery Pack.
The Battery is a Lithium ion one (a.k.a.: lithium polymer, LIPO Battery).
Dimensions: 9.7 x 4.3 x 2.3 cm (3.82 x 1.71 x 0.88 in) (L x W x H)
Weight: 119 g (4.2oz)
9) The 17 Servos are powered by 5 Ni-MH AA Rechargeable Batteries (at 1.2 X 5 = 6 Volts). The batteries are inserted into a Battery Case, which was purchased as a Plastic Battery Case Storage Box Holder with Wire Leads for 5 X AA on eBay for $1.28.
The batteries used are 5 Panasonic Eneloop 2000mAh AA Ni-MH (Nickel Metal Hydride) Rechargeable Batteries, which are charged using a Panasonic Charger. The cost pertaining to these Batteries and Charger was not included in the price of the Components required for building the Robot since some people might already have these items, and these components may be used for other purposes.
10) The following other items are required for building the Robot. These can be purchased on eBay at a very low price (a few dollars per item), not totaling more than $28, which will keep the overall cost of the components for the Robot at $300 or less.
In buying these items, please note that one may purchase some of them as kits, along with their Raspberry Pi Computer. Several Vendors sell Raspberry Pi kits, including some of these components.
- Cables
Female-Male Dupont Cable, purchased as a 40pcs Male to Female Dupont Jumper Wire Ribbon Cable on eBay for less than $2. This Ribbon Cable is used to connect the Servo Control Input Signal Wire from the Servos to the Raspberry Pi GPIO Pins(with added Resistors in the middle). Only 17 of the wires are actually needed.
Male-Male Dupont Cable, purchased as a 40pcs Male to Male Dupont Jumper Wire Ribbon Cable on eBay for less than $2. This Ribbon Cable is used to connect the Servo Power and Ground Wires from the Servos to the 5 Ni-MH AA Battery Pack (via a Breadboard in our examples). Only 34 (2x17) of the wires are actually needed.
- Small Breadboard
- 17 1k-Ohm Resistors to add between the Servos and the Raspberry Pi GPIO Pins for safety.
- Heat Shrink Tubing to cover the Resistors
- Screws to screw the 3D-Printed Parts to the Servo Brackets.
- 2x LED Lights for the Robot�s eyes, although this hasn�t been implemented as of today.
- A few Jumper Wires might be handy
All the Code, Services and Software used for creating and building the Robot were free of charge.
Moreover, one will need a USB Keyboard and USB Mouse, as well as an HDMI compatible Monitor in order to interact with the Raspberry Pi. The price of these items were not included in the list of components required for building the Robot, for it is assumed that most people will already have these items, and such items could be used as part of a Raspberry Pi Computer, or with any other computer.
Finally, some basic tools are required for assembling some components, such as screwdrivers, pliers� and eventually a soldering iron (although the prototype built as of today has been assembled using a Breadboard without soldering the parts).
Total costs
Depending on your country of residence, the exchange rate applicable in your Country, and the shipping costs, the cost of the Robot may slightly exceed $300, but this shouldn�t be by a substantial amount.
| Component |
Price |
| Raspberry Pi |
35 |
| USB WiFi Dongle |
10 |
| Mini Speaker |
15 |
| USB Microphone |
3 |
| Servos |
88 |
| Servo Brackets |
75 |
| 3D Printed Parts |
30 |
| Raspberry Pi Battery |
16 |
| Other Items (N. 10 in list) |
28 |
| Total Cost in US $ |
300 |
|