MinnowBoard MAX is an open hardware embedded board designed with the Intel(R) Atom(TM) E38xx series SOC (formely Bay Trail). The MinnowBoard Turbot is a backward compatible revision with performance and hardware improvements. https://www.minnowboard.org/learn-more/minnowboard-max-compatible-with-upgrades
For product overview and faq see https://www.minnowboard.org/faq
For technical details see https://www.minnowboard.org/board-viewer or the legacy board https://www.minnowboard.org/minnowboard-max
MRAA has only been tested with 64 bit firmware version 0.73 or later.
For SPI support you need to load the low_speed_spidev kernel module and that will create the /dev/spidev0.0 device node. MRAA only knows about this one SPI bus and no other.
The low speed I/O connector supported as per table below. This assumes default BIOS settings, as they are not dynamcially detected If any changes are mode (Device Manager -> System Setup -> South Cluster -> LPSS & CSS) them MRAA calls will not behave as expected.
The platform is chardev capable on newer kernels.
Documentation shows i2c on bus #5, ACPI shows it on bus #6, but driver uses bus #7.
| MRAA Number | Physical Pin | Function | Sysfs GPIO | Notes |
|---|---|---|---|---|
| 1 | 1 | GND | ||
| 2 | 2 | GND | ||
| 3 | 3 | 5v | ||
| 4 | 4 | 3.3v | ||
| 5 | 5 | SPI_CS | 220 | SPI (via low_speed) |
| 6 | 6 | UART1_TXD | 225 | UART1 |
| 7 | 7 | SPI_MISO | 221 | SPI (via low_speed) |
| 8 | 8 | UART1_RXD | 224 | UART1 |
| 9 | 9 | SPI_MOSI | 222 | SPI (via low_speed) |
| 10 | 10 | UART1_CTS | 227 | GPIO |
| 11 | 11 | SPI_CLK | 223 | SPI (via low_speed) |
| 12 | 12 | UART1_RTS | 226 | GPIO |
| 13 | 13 | I2C_SCL | 243 | /dev/i2c-7 |
| 14 | 14 | I2S_CLK | 216 | GPIO |
| 15 | 15 | I2C_SDA | 242 | /dev/i2c-7 |
| 16 | 16 | I2S_FRM | 217 | GPIO |
| 17 | 17 | UART2_TXD | 229 | UART2 |
| 18 | 18 | I2S_DO | 219 | GPIO |
| 19 | 19 | UART2_RXD | 228 | UART2 |
| 20 | 20 | I2S_DI | 218 | GPIO |
| 21 | 21 | GPIO_S5_0 | 82 | GPIO |
| 22 | 22 | PWM0 | 248 | PWM Chip 0 Channel 0 |
| 23 | 23 | GPIO_S5_1 | 83 | GPIO |
| 24 | 24 | PWM1 | 249 | PWM Chip 1 Channel 0 |
| 25 | 25 | S5_4 | 84 | GPIO |
| 26 | 26 | IBL_8254 | 208 | GPIO / I2S MCLK (tb) |
*(tb) New assignment on the MinnowBoard Turbot
** On 3.18+ kernels, sysfs GPIO numbers are computed using:
new_value = old_value | 0x100
The MinnowBoard Turbot has one user programmable built-in LED. This is exposed as a GPIO from MRAA.
| MRAA Number | Physical Pin | Function | Sysfs GPIO | Notes |
|---|---|---|---|---|
| 27 | N/A | D2_LED | 104 | Active low |