by Web FishJan 1, 2013 @ 12:31pm
The heart of PilotFish navionics package. The board runs all decision-making software, reading input data from all sensors (navigation and others), controlling propulsion and directional control, feeding up-link telemetry data and ensuring data persistence for post-mission download.
- Current selection: Netduino Plus 2
- Status: Finalized
- Criteria: Low power footprint, as many I/O channels as possible, standard I/O, available off-the-shelf add-ons, standard storage, easy programmability/debugging, small physical footprint
- Finalists: Netduino Plus 2, Arduino Mega 2560
- Main decision factors: 22 I/O pins with dynamic GPIO/Analog/UART/I2C allocation, Arduino shield compatible, sufficient code storage area, .NET Micro Framework, on-board SD card support

(click image for larger view)
Spec summary:
- STMicro 32-bit microcontroller
- Speed: 168MHz, Cortex-M4
- Code Storage: 384 KB
- RAM: 100+ KB
- 22 GPIO pins
- Up to 4 UARTS
- I2C channel
- micro sd (up to 2 GB)
- input: 7.5 - 9.0 VDC or USB powered
- output: 5 VDC and 3.3 VDC regulated
Caveats:
- Even though 22 I/O pins look like a lot, in reality we'll need every pin available to communicate with the peripheral devices. Whenever possible, we might need to utilize I2C bus to preserve general I/O pins for "dumber" sensors and devices.