Please note! The above video was shot with the Pixelduino running at 8MHz. It has since been given an upgrade to 16MHz! See the following video showing off what the Pixelduino can do at the higher clock speed, and with optimized graphics routines:
The Pixelduino is an Arduino-compatible microcontroller that features a 1.5" 128x128 pixel color OLED screen and a MicroSD slot!
There are all sorts of things you can do with a device like this. You can create wearables like a watch, bracelet, pendant, or buckle that displays color images, attach sensors and display data in text or visual form, display debug information, create a graphics user interface, or even make simple retro games.
Features / specifications
- Processor : Atmel Atmega328P @ 5V / 16MHz
- IO pins : 14 digital, 6 analog
- Memory : 32K flash, 2K RAM
- Voltage regulator : TPS61202 5V boost converter
- Input voltage : 1.5 - 5.5V recommended
- Available supply current : 100mA @ 0.5V, 1A @ 3V, 1.3A @ 3.7V
- Power connector : JST PH (standard for small LiPo cells)
- Display : 128x128 16-bit color 1.5" (38mm) OLED w/ SSD1351 driver
- PCB Size : 1.7" x 1.7" (43 x 43mm)
The display on the Pixelduino is compatible with Adafruit's GFX library. This library provides functions for blitting images, drawing primitives like lines and circles, and even includes basic bitmapped font support.
The theoretical maximum speed of this display when streaming from the SD card and refreshing the entire screen is ~10 fps. This is based on the speed of the SPI bus and the amount of data that needs to be pushed around.
The display controller also has some graphics acceleration built in, allowing you to redraw only specific parts of the screen (enabling sprite rendering by tracking dirty rectangles) or change the display offset to scroll vertically.
(Of course, if you want to do horizontal scrolling in hardware, you can always rotate the screen by 90 degrees!)
The Pixelduino is also compatible with the Arduino's SPI and SD libraries. Communication with the display and MicroSD card are both handled with the SPI bus on pins 10-13. Pins 8 and 9 are also used to command the display. Aside from these, the rest of the pins are available for any use. The I2C bus for example is available on pins A4 and A5.
In the image above you can see the board includes a convenient 2mm JST PH connector, just like those found on small LiPo batteries and some alkaline battery packs.
The board can run on 1 to 3 alkaline, lithium, or NiMh batteries, as well as single-cell LiPo batteries. The on-board boost regulator efficiently steps the voltage up to the 5V the board requires, and has a built in linear regulator to step the voltage down when needed.
(Supplied USB programmer may differ from photo.)
New firmware can be loaded using the Arduino IDE with the same USB serial FTDI programmers boards like the Arduino Pro use, or with an ISP programmer using a pogo-pin adapter.
The circuit seen in the video is a proof of concept using the same screen and processor that will be used on the final board. The final design is complete and ready to go into production soon after we reach our funding goal.
(The images above represent the upgraded 16MHz PCB!)
The Pixelduino is open hardware and the schematics and PCB layout will be made available so you can manufacture them yourself or learn from the design and improve upon it!
Here is the timeline for completing each phase of the project:
- Design schematic. - DONE
- Layout PCB. - DONE
- Create Bill of Materials. - DONE
- Assemble and test prototype. - DONE
- Acquire funding on Kickstarter. - IN PROGRESS
- Thank everyone for their support!
- Order parts + get first round of PCBs made for testing.
- Order shipping materials.
- Assemble and test boards.
- If necessary, correct any mistakes and order another round of PCBs for assembly and testing.
- Order final boards.
- Assemble boards.
- Burn bootloader.
We set out to design this board after seeing a similar product with a tiny monochrome screen that we thought we could improve upon. But hardware is expensive, and color OLED screens even more so. To produce these boards at this price point, we need to order several hundred of them at a time. And we don't even know if there's a market for it. But we hope there is!
Please back our Kickstarter.
- Rabid Prototypes
Risks and challenges
While there is always some risk involved when designing new hardware, this board is based on proven designs, and we've intentionally kept things simple. We've also carefully calculated what everything will cost, including getting quotes from the manufacturer of the OLED screens, which are the most expensive component, and we've selected components which are available in large quantities, so as not to encounter any supply issues.Learn about accountability on Kickstarter
- (14 days)