UEXT connectors
Universal EXTension (UEXT) is a circuit of a connector that includes a power line and three serial data interfaces: UART, I2C, SPI. Developed by Olimex and is open and free. UEXT specification.
UEXT connector consists of 10 pins, 5 pins in two rows in a plastic frame. The distance between pins is 2.54 mm. The connector connects to a 2x5 (10-pin) IDC socket and usually connects to flat cable. See also [1].
Technical specifications
UEXT-connectors on the Wiren Board controller board
There are two UEXT-connectors on the board of Wiren Board controller v2.8. But in the second connector, the MISO, MOSI, SCK lines are duplicated with the corresponding pins of the first connector. TxD and RXD lines are duplicated with RS-485 inputs.
Pin | Name | I/O | Logic | - | - |
---|---|---|---|---|---|
1 | 3.3 V | S | S | +3.3 volt | |
2 | GND | S | S | Ground | |
3 | TxD | O | PP | Debug UART/en Tx | |
4 | RXD | I | PP | [Debug UART/en]] Rx | |
5 | SCL | O | OD | Hardware I2C, SCL | |
6 | SDA | I/O | OD | Hardware I2C, SDA | |
7 | MISO | I | PP | SPI Bus, MISO | |
8 | MOSI | O | PP | SPI Bus, MOSI | |
9 | SCK | O | PP | SPI Bus, SCK | |
10 | SSEL | O | PP | GPIO 19 | SPI Bus, CS |
Pin | Name | I/O | Logic | - | - | notes |
---|---|---|---|---|---|---|
1 | 3.3 V | S | S | +3.3 volt | ||
2 | GND | S | S | Ground | ||
3 | TXD | O | PP | sc16is752 UART0 Tx | parallel to RS-485 | |
4 | RXD | I | PP | sc16is752 UART0 Rx | parallel to RS-485 | |
5 | SCL | O | OD | GPIO 51 | I2C, SCL | |
6 | SDA | I/O | OD | GPIO 53 | I2C, SDA | |
7 | MISO | I | PP | SPI Bus, MISO | ||
8 | MOSI | O | PP | SPI Bus, MOSI | ||
9 | SCK | O | PP | SPI Bus, SCK | ||
10 | SSEL | O | PP | GPIO 91 | SPI Bus, CS |
Порты 3,4 (UART) разъёма UEXT2 подключены к чипу SC16IS752 и присутствуют только в модификациях с этим чипом (опции GPS или RS-485).
Эти порты подключены параллельно трансиверу RS-485, их невозможно использовать одновременно с RS-485.