| mraa
    1.9.0
    Low Level Skeleton Library for Communication on GNU/Linux platforms | 
UP Board is based on the Intel(R) Atom(TM) x5-Z8350 SoC (formerly Cherry Trail). It includes 1/2/4GB RAM, 16/32/64GB eMMC flash, 6 USB2.0 ports, 1 USB 3.0 OTG port, 1 Gigabit Ethernet, HDMI and DSI/eDP Graphics ports, RTC and a 40-pin I/O header. The form-factor for the board is based on the Raspberry Pi 2, and can be used with many of the add-on HAT boards designed for the Raspberry Pi.
PWM PWM frequency range is from 293 Hz to 6.4 MHz. 8-bit resolution is supported for duty-cycle adjustments, but this reduces for frequencies > 97.6kHz
I2C 2 I2C channels support standard-mode (100kHz) and fast-mode (400kHz). Bus frequency can be selected in BIOS settings. Note that, unlike Raspberry Pi, the I2C controller issues Repeated-START commands for combined transactions (e.g. a write-then-read transaction) which may not be supported by some I2C slave devices. For such devices, it is advisable to use separate write and read transactions to ensure that Repeated-STARTs are not issued.
SPI Bus frequencies up to 25MHz are supported, in steps which are less granular at higher speeds. E.g. Available speeds include: 25MHz, 12.5MHz, 8.33MHz, 6.25MHz, 5MHz, 4.167MHz, 3.571MHz, 3.125MHz, etc. Please be aware that speeds in between those steps will be rounded UP to the next nearest available speed, and capped at 25MHz. 2 chip-selects are available, one natively (SPI CS0) and one by GPIO (SPI CS1).
UART 1 high-speed UART is available, supporting baud rates between 300 and
ADC 1 8-bit single-channel ADC (TI ADC081C021) is available on pin 7.
Please note that a kernel with UP board support is required to enable the I/O interfaces above. Refer to https://up-community.org for more information.
The GPIO numbering in the following pin mapping is based on the Raspberry Pi model 2 and B+ numbering scheme.
Note that there is an enum to use wiringPi style numbers.
| MRAA Number | Physical Pin | Function | Sysfs GPIO | mraa device | 
|---|---|---|---|---|
| 1 | P1-01 | 3V3 VCC | ||
| 2 | P1-02 | 5V VCC | ||
| 3 | P1-03 | I2C SDA | 2 | I2C0 | 
| 4 | P1-04 | 5V VCC | ||
| 5 | P1-05 | I2C SCL | 3 | I2C0 | 
| 6 | P1-06 | GND | ||
| 7 | P1-07 | GPIO(4) | 4 | ADC0 (iio:device0) | 
| 8 | P1-08 | UART TX | 14 | UART0 | 
| 9 | P1-09 | GND | ||
| 10 | P1-10 | UART RX | 15 | UART0 | 
| 11 | P1-11 | UART_RTS | 17 | UART0 | 
| 12 | P1-12 | I2S CLK | 18 | |
| 13 | P1-13 | GPIO(27) | 27 | |
| 14 | P1-14 | GND | ||
| 15 | P1-15 | GPIO(22) | 22 | |
| 16 | P1-16 | GPIO(23) | 23 | |
| 17 | P1-17 | 3V3 VCC | ||
| 18 | P1-18 | GPIO(24) | 24 | |
| 19 | P1-19 | SPI MOSI | 10 | SPI0,1 | 
| 20 | P1-20 | GND | ||
| 21 | P1-21 | SPI MISO | 9 | SPI0,1 | 
| 22 | P1-22 | GPIO(25) | 25 | |
| 23 | P1-23 | SPI SCL | 11 | SPI0,1 | 
| 24 | P1-24 | SPI CS0 | 8 | SPI0 | 
| 25 | P1-25 | GND | ||
| 26 | P1-26 | SPI CS1 | 7 | SPI1 | 
| 27 | P1-27 | I2C SDA0 | 0 | I2C1 | 
| 28 | P1-28 | I2C SCL0 | 1 | I2C1 | 
| 29 | P1-29 | GPIO(5) | 5 | |
| 30 | P1-30 | GND | ||
| 31 | P1-31 | GPIO(6) | 6 | |
| 32 | P1-32 | PWM0 | 12 | PWM0 | 
| 33 | P1-33 | PWM1 | 13 | PWM1 | 
| 34 | P1-34 | GND | ||
| 35 | P1-35 | I2S FRM | 19 | |
| 36 | P1-36 | UART_CTS | 16 | UART0 | 
| 37 | P1-37 | GPIO(26) | 26 | |
| 38 | P1-38 | I2S DIN | 20 | |
| 39 | P1-39 | GND | ||
| 40 | P1-40 | I2S DOUT | 21 | 
 1.8.11
 1.8.11