The Scribbler 2 (S2) Robot is one of Parallax’s Propeller-based robot. At first look the S2 appears to be a distant cousin to the original blue Scribbler (S1), but a look under the shell shows generations of electronic evolution! Some of the improvements the P8X32A multi-core microcontroller with eight processing cogs, faster motors with encoder feedback for precision movement, bright bi-color LEDs, a loud speaker, a microphone and a truly accessible hacker port! Applications such as pen-based artwork, XBee communication between robots and computers, voice synthesis, robot following and classroom competition are all possible with the S2.
Scribbler 2 Design Goals
The most important design goals we applied for S2 include the following:
- Propeller P8X32A-Q44 support for true robotic multi-core processing, which now enables a variety of robot tasks, sensors and drive routines to be compartmentalized into tidy code objects and processor COGs
- Backward-compatibility with the existing Scribbler GUI
- Wide-access “hacker port” with many I/Os and a substantial power supply
- Compatibility with existing third-party hardware designs, such as the Georgia Tech IPRE Fluke
- Improvements to drive system with wheel encoder feedback, stronger motors and a straight-steering robot
But there’s so much more as you’ll see down below. The Propeller has enabled us to provide a highly capable platform that brings forward many new capabilities. Consider parallel processing, speech synthesis and the expanded hacker port, not to mention the variety of languages now available for the Propeller!
What does S2 lose in this redesign compared to original Scribbler? Coding in PBASIC, since the S2 uses Propeller; we’re also dropping the consumer product safety commission (CPSC) testing for the under-13 year-old audience since we market and support an older audience with this robot. This has two additional benefits of being able to use a louder amplifier and speaker and more powerful motors!
| Feature |
Specification |
| Microcontroller |
P8X32A-Q44 multi-core processor |
| Power Supply |
6 AA or NiMH batteries |
| Hacker Port |
5.0V @ 1.2A power supply with 6 digital I/Os and 2 analog inputs arranged with handy 3-pin connectors (I/O, Vdd, Vss) |
| Light sensors |
Operating Range: 0 - 300 Lux
Frequency response (-3dB) 700 Hz |
| Infrared object detection and line following |
Infrared object detection with 2 alternating emitters and 1 receiver
Infrared line detection with 2 emitter-receiver pairs
Internal stall sensor on rear wheel |
| Lights |
3 high-intensity bi-color LEDs
1 power LED |
| Motors |
2 DC motors provide 20-80 RPM wheel speed |
| Encoder feedback |
507 counts/revolution (0.5 mm resolution) |
| Microphone |
60 - 7,200 Hz |
| Speaker |
700 - 7200 Hz with software-adjustable volume |
| Dimensions |
7.4 x 6.25 x 3.2 in (188 x 158.8 x 81 mm) |
| Operating Temperature |
+50 to +104 °F(+10 to +40 °C) |
Open-Source
The S2 is also a distinguished member of Parallax’s open-source design family. Customers may freely download all design files: PCB layouts, Bill of Materials, SolidWorks mold designs, mechanical assembly, GUI Perl source code and all Propeller code. Customers may use the entire design for their own commercial products.
S2 Design Team
Parallax thanks the Scribbler team for their efforts on this two-year project. This team includes Ben Wirz (Element), Phil Pilgrim (Bueno Systems), Asian manufacturing partners and the Parallax staff in Rocklin, California, Hong Kong and China who will diligently test the product, prepare manuals, design packaging, and develop support/marketing programs around S2.
If you have any additional questions we could answer about the S2 please contact Parallax via e-mail.