Originally published at: http://www.emlid.com/introducing-navio2/
We are happy to announce Navio2 - the new version of Navio autopilot.
We have listened closely to our community and included numerous improvements in Navio2.
New features in Navio2
Dual IMU. We’ve added second IMU chip to improve flight experience and for redundancy.
Advanced power circuitry. Triple ideal diode or-ing scheme was already present on Navio+, Navio2 also features overvoltage and overcurrent protection circuitry on the power module port to protect both the board and your Raspberry Pi.
Improved MS5611 performance. Transactions from other chips on the bus, which MS5611 is connected to, can produce noise during the conversion. We left MS5611 the only sensor on the I2C bus to overcome this.
PCA9685 PWM generator replaced with a microcontroller. On previous Navio version PWM generation was handled by PCA9685 chip. Main limitation of this chip is the inability to control frequencies for separate channels. This lead to problems with motors and servos that work on different frequencies. To eliminate that problem we used a microcontroller that allows to set frequencies for output channels by groups.
PPM\SBUS decoding done by microcontroller instead of DMA. On Navio+ we used DMA to sample PPM signal which was quite heavy on system resources. On Navio2 a microcontroller handles PPM\SBUS sampling leaving processor cores of Raspberry Pi 2 for your tasks.
AUX SPI. Navio2 is the first HAT to utilize AUX SPI controller on Raspberry Pi. Using two SPI controllers allows us to distribute sensors more efficiently. Having twice the bandwidth of other Raspberry Pi based solutions, we are managing to move more data at a greater speed.
ADC port. Using additional ADC channels on Navio+ was not user friendly due to ADC channels being only available on pads at the bottom of the board. On Navio2 these channels are easily accessible on a DF13 port.
Better Linux integration. PWM, ADC, SBUS and PPM are integrated in Linux sysfs allowing for easy access from any programming language. Even deeper integration is coming in the future.
Other small changes
- Right angle servo header
- RGB LED position in the board center for better LED visibility
- Pulled up pins in UART port to allow easy 3DR Radio connection
- Nylon screws in the package to avoid magnetic interference
- Camera cable cutout
- PWM channels are protected by ESD clamps
You can find more information and order Navio2 here.