Easily to Use Image Sensors for Microcontrollers and DSPs
No Complicated Shuttering or Timing Signals
Embedded vision applications have needs that are different from digital photography. Pixels are acquired to be processed, and features such as flexible acquisition, random pixel access, and ease of use are more important than mere pixel count. Indeed, too many pixels can be problematic, as the sheer volume of data generated slows down frame rates and overwhelms any processor with data.
Unfortunately, most commercially available image sensors are not suited to embedded vision applications, especially where size and complexity are dominant factors: Active pixel sensors and CCDs generally require precise shutter operation, and use a complicated interface in which the image sensor drives timing (e.g. is the “master”), and not the processor. When coding a specific application, you are left having to synchronize your algorithm to that of the image sensor, which in many cases is impractical or impossible.
Centeye’s image sensors, on the other hand, were designed with embedded vision applications in mind. All of our image sensors contain at least these three key benefits:
- The interface is asynchronous and easy to use, even with a simple 8-bit microcontroller. With Centeye’s image sensors, YOU control the timing.
- The pixel circuits are shutterless and are always adapting to light levels and generating an output. You then just sample the pixels at whatever rate is convenient for you. You do not have to reset pixels and wait for them to integrate.
- Our image sensors are flexible- you can choose to grab the entire pixel array or just a window of pixels, and you can do either of these while downsampling, even by different amounts in the X and Y directions.
Some of our image sensors include additional features, for example analog processing steps performed on the chip or even in the focal plane.
To purchase image sensor chips or ask questions, contact us
Current Image Sensor Chips
Stonyman / Hawksbill Series (recommended for new designs)
We recommend either the Stonyman or the Hawksbill chip for all new designs. Both vision chips are very easy to use and require a minimal interface: 5 digital inputs and 1 analog output. These chips were designed to interface with microcontroller and DSPs. The digital inputs are pulsed according to an intuitive and easy to understand sequence (no precise timing needs), and the analog output contains the analog pixel signal which may be digitized by an ADC.
Stonyman chip
The Stonyman chip contains a 112 x 112 pixel array arranged in a conventional square array (like pretty much any other image sensor). The Stonyman chip also contains in-pixel binning circuitry, allowing you to construct square or rectangular “super pixels” from the raw pixel array. The Stonyman chip uses shutterless logarithmic response pixels.
Hawksbill chip
The Hawksbill chip has the exact same interface (including pad layout / bonding diagram) as the above Stonyman chip, but has a 136 x 136 array of pixels arranged in a hexagonal form. The Hawksbill does not support pixel binning.
Datasheet and Instructions: Stonyman and Hawksbill Datasheet
To purchase image sensor chips or ask questions, contact us
Mature Image Sensor Chips
We have limited quantities of these chips in stock, but can resume production if demand is adequate.
Overview Video of Faraya, Firefly, and Tam series chips
(Access slides here)
Tam Series
The Tam series of chips are the simplest image sensor chips we have ever made. These chips are used in our popular ArduEye Rox1 shield boards. They can be operated with as little as five connections: Ground, Power, Clock, Reset, and AnalogOut. The AnalogOut pin contains the analog pixel value (logarithmically compressed). Pulsing the Clock signal increments a counter that allows individual pixels to be read out row-wise. Pulsing the Reset line resets the counter to read out the top left pixel. It does not get much simpler than this.
Two Tam series chips are available, the Tam2 with a 16×16 resolution and the Tam4 with a 4×32 resolution, implemented with rectangular pixels. The Tam4 chip is appropriate for sensing information along one axis, for example one dimensional optical flow.
- Tam2: 16 x 16 resolution of square pixels
- Tam4: 4 x 32 resolution of rectangular pixels
To purchase image sensor chips or ask questions, click here
Firefly Series
Firefly series chips contain a logarithmic pixel array with binning in the focal plane. Binning is implemented with “switches” between pixel circuits. The native resolution pixel array may be binned and downsampled by a factor of 1, 2, 4, or 8 independently in each of the X and Y directions. It is also possible for the binning array to be offset- the top-left binned pixel could, for example, be formed from rows and columns 1 through 8, or could be offset so that, for example, rows 1 through 8 and columns 2 through 9 form the top-left binned pixel.
These chips are generally easy to use. The primary interface is through a 10-bit wide PIO12 interface.
Two chips are available: FireflyBig with a 480×256 native resolution, and FireflySmall with a 128×256 native resolution.
Both Firefly series chips include on-chip bias generators, PIO12 interface, linear voltage regulator for analog circuits, and on-chip 8-bit ADC.
- FireflySmall: 128 x 256 array with in-focal plane binning
- FireflyBig: 480 x 256 array
To purchase image sensor chips or ask questions, click here
Faraya Series
Faraya series chips are similar to the Firefly series of chips, except that binning is performed with a separate capacitor array located adjacent to the pixel array. This may result in a lower acquisition time, but allows smoothing to be implemented beyond simple binning using switched capacitor techniques. The Faraya series chips are slightly more difficult to operate.
Two chips are available: Faraya256plus with a 256×256 native resolution, and Faraya64plus with a 64×64 native resolution.
Both Faraya series chips include on-chip bias generators, PIO12 interface, and an on-chip 8-bit ADC. The Faraya64plus chip also includes an on-chip linear voltage regulator.
- Faraya256: 256 x 256 array
- Faraya64: 64 x 64 array
Datasheets and Instructions for All Chips
Stonyman / Hawksbill series chips (Stonyman and Hawksbill)
Tam series chips (Tam2 and Tam4)
Firefly series chips (FireflySmall and FireflyBig)
Faraya series chips (Faraya64 and Faraya256)
PIO12B instructions (needed for Firefly and Faraya series) The PIO12B interface is a bi-directional parallel interface (8 digital IO, 2 digital in, 1 analog out) allowing multiple chips to be connected to the same digital bus but allow individual chips or groups of chips to be operated in parallel or in sequence.
To purchase image sensor chips or ask questions, contact us