# Low-speed expansion connectors

Source: [https://docs.qualcomm.com/doc/80-88500-5/topic/low-speed_expansion_connectors.html](https://docs.qualcomm.com/doc/80-88500-5/topic/low-speed_expansion_connectors.html)

## Low-speed expansion connector 1

The low-speed expansion connector 1 provides the following functionalities:

- 2x UART
- 2x I2C
- 1x SPI
- 1x PCM
- 12x GPIOs
- DC power
- Ground

The GPIOs labeled Qualcomm Universal Peripheral (QUP) have additional low-speed interface capabilities (UART, SPI, I2C).

- For more details on how to use the QUP interfaces, see <cite class="cite">Qualcomm Robotics RB5 Platform Software Porting Guide</cite> (80-88500-1).
- For the pin map and GPIO details, see <cite class="cite">QRB5165 Pin Assignment and GPIO Configuration Spreadsheet</cite> (80-PV086-1A) on [www.qualcomm.com](http://www.qualcomm.com). Several GPIOs can be used to wake up the application processor.

Low-speed interfaces can be used to control various peripherals, such as audio functions.

| Wake-up function | Additional info | SoM pin | GPIO | Signal | Pin number | Pin number | Signal | GPIO | SoM pin | Additional info | Wake-up function |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| – | – | – | – | **GND** | 1 | 2 | **GND** | – | – | – | – |
| – | QUP13 | E42 | 36 | UART0\_CTS | 3 | 4 | PWR\_BTN\_N | – | A40 | PHONE\_ON | – |
| – | QUP13 | D42 | 38 | UART0\_TXD | 5 | 6 | RST\_BTN\_N | – | A42 | VOL- | – |
| Yes | QUP13 | D40 | 39 | UART0\_RXD | 7 | 8 | SPI0\_SCLK | 54 | C42 | QUP17 | – |
| – | QUP13 | D41 | 37 | UART0\_RTS | 9 | 10 | SPI0\_MISO | 52 | G36 | QUP17 | – |
| Yes | QUP12 | C45 | 35 | UART1\_TXD | 11 | 12 | SPI0\_CS | 55 | F36 | QUP17 | Yes |
| – | QUP12 | B46 | 34 | UART1\_RXD | 13 | 14 | SPI0\_MOSI | 53 | F37 | QUP17 | – |
| – | QUP4 | D35 | 9 | I2C0\_SCL | 15 | 16 | PCM\_FS | 141 | A10 | PCM\_FS/I2S0\_WS | – |
| – | QUP4 | A46 | 8 | I2C0\_SDA | 17 | 18 | PCM\_CLK | 138 | D37 | PCM\_CLK/I2S0\_CLK | Yes |
| – | QUP15 | E43 | 45 | I2C1\_SCL | 19 | 20 | PCM\_DO | 140 | D38 | PCM\_DO/I2S0\_D1 | – |
| Yes | QUP15 | F44 | 44 | I2C1\_SDA | 21 | 22 | PCM\_DI | 139 | F40 | PCM\_DI/I2S0\_D0 | – |
| Yes | QUP1 | H33 | 4 | GPIO-A | 23 | 24 | GPIO-B | 136 | K39 | PCM0\_MCLK | Yes |
| – | QUP1 | H31 | 5 | GPIO-C | 25 | 26 | GPIO-D | 7 | H32 | QUP1 | Yes |
| – | QUP1 | H30 | 6 | GPIO-E | 27 | 28 | GPIO-F\* | 46 | E41 | DISPLAYMIPI\_ERR\_FG/QUP15 | – |
| Yes | DISPLAYVSYNC | F43 | 66 | GPIO-G [^1^](https://docs.qualcomm.com/doc/80-88500-5/topic/low-speed_expansion_connectors.html#fntarg_1) | 29 | 30 | GPIO-H\* | 116 | K41 | DISP\_RST\_N | – |
| Yes | CAM0\_RST\_N | K37 | 93 | GPIO-I [^2^](https://docs.qualcomm.com/doc/80-88500-5/topic/low-speed_expansion_connectors.html#fntarg_2) | 31 | 32 | GPIO-J~ | 114 | J30 | CAM0\_PWDN | – |
| Yes | CAM1\_RST\_N | G42 | 92 | GPIO-K | 33 | 34 | GPIO-L~ | 109 | J31 | CAM1\_PWDN | Yes |
| – | VREG\_S4A\_1P8 | D45 | N/A | **1.8 V-A** | 35 | 36 | **SYS\_DCIN** | N/A | – | DC12V from barrel jack | – |
| – | From on board regulator | – | N/A | **5 V** | 37 | 38 | **SYS\_DCIN** | N/A | – | DC12V from barrel jack | – |
| – | – | – | – | **GND** | 39 | 40 | **GND** | – | – | – | – |

[^1^](https://docs.qualcomm.com/doc/80-88500-5/topic/low-speed_expansion_connectors.html#fnsrc_1)  dedicated display GPIOs (can be used for other functions)

[^2^](https://docs.qualcomm.com/doc/80-88500-5/topic/low-speed_expansion_connectors.html#fnsrc_2)  dedicated camera GPIOs (can be used for other functions)

## Low-speed expansion connector 2

The low-speed expansion connector 2 provides the following functionalities:

- 3x DMIC support
- Additional 4‑bit I2S audio interface
- CAN interface
- Stereo audio amp outputs
- 2x camera CCI I2C
- PMIC PWM and ADC pins
- 1x QUP interface
- Spare GPIOs
- Battery ID/therm
- Other additional functions

Low-speed interfaces can be used to control various peripherals, such as audio functions.

| Wake-up function | Additional info | SoM pin | GPIO | Signal | Pin number | Pin number | Signal | GPIO | SoM pin | Additional info | Wake-up function |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| – | CAM3\_RST\_N | G44 | 144 | GPIO-U | 1 | 2 | GPIO-Z | 25 | J36 | CAM4\_RST\_N | – |
| – | – | K43 | 152 | DMIC CLK1 | 3 | 4 | CAN\_H | – | – | From onboard CAN | – |
| – | – | K44 | 153 | DMIC DATA1 | 5 | 6 | CAN\_L | – | – | From onboard CAN | – |
| Yes | I2S1\_DATA2/extcodec/CAM0\_STROBE\_N | K30 | 150 | GPIO-V | 7 | 8 | **1.8V-A** | – | D45 | – | – |
| – | – | J43 | 154 | DMIC CLK2 | 9 | 10 | **GND** | – | – | – | – |
| – | – | J44 | 155 | DMIC DATA2 | 11 | 12 | PM\_GPIO-A | – | K38 | PMGPIO 6 (PM8150L) - PWM | – |
| – | I2S1\_DATA3/extcodec/CAM5\_RST\_N | K31 | 151 | GPIO-W | 13 | 14 | PM\_GPIO-B | – | A8 | PMGPIO 10 (PM8150L) - PWM | – |
| Yes | – | J45 | 158 | DMIC CLK3 | 15 | 16 | GPIO-M | 125 | A9 | QUP9 | – |
| – | – | J46 | 159 | DMIC DATA3 | 17 | 18 | GPIO-N | 126 | B45 | QUP9 | Yes |
| – | PM8250\_GPIO3 | C5 |  | PM\_GPIO-F | 19 | 20 | GPIO-O | 127 | B40 | QUP9 | – |
| – | CCI\_I2C\_SCL2 | H35 | 106 | CCI\_I2C\_SCL2 | 21 | 22 | GPIO-P | 128 | D5 | QUP9/BOOT\_CONFIG\_0 | Yes |
| – | CCI\_I2C\_SDA2 | H34 | 105 | CCI\_I2C\_SDA2 | 23 | 24 | GPIO-Q | 147 | K27 | I2S1\_WS/extcodec/SWIRE | Yes |
| Yes | CCI\_I2C\_SCL3 | H36 | 108 | CCI\_I2C\_SCL3 | 25 | 26 | GPIO-R | 146 | K26 | I2S1\_CLK/extcodec/SWIRE | – |
| – | From onboard WSA amp | – | – | SPK0\_P | 27 | 28 | GPIO-S | 148 | K28 | I2S1\_DATA0/extcodec | – |
| – | From onboard WSA amp | – | – | SKP0\_M | 29 | 30 | GPIO-T | 149 | K29 | I2S1\_DATA1/extcodec | – |
| – | From onboard WSA amp | – | – | SPK1\_P | 31 | 32 | PM\_AMUX1 | – | C7 | PM8150LAMUX1 - ADC | – |
| – | From onboard WSA amp | – | – | SPK1\_M | 33 | 34 | PM\_AMUX2 | – | C9 | PM8150BAMUX1 - ADC | – |
| – | CCI\_I2C\_SDA3 | J35 | 107 | CCI\_I2C\_SDA3 | 35 | 36 | BATT\_THERM | – | K46 | BATT\_THERM | – |
| – | PM8250 AMUX1/MDM\_SKIN\_THERM | B38 | – | PM\_AMUX3 | 37 | 38 | BATT\_ID | – | K45 | PM8150B- BATT\_ID | – |
| – | or VPH\_PWR | J47 | – | **VBAT** | 39 | 40 | **USB\_VBUS** | – | E47 | USB\_VBUS | – |
| – | – | – | – | **GND** | 41 | 42 | **GND** | – | – | – | – |
| – | CAM0\_STROBE | J27 | 14 | GPIO-X | 43 | 44 | GPIO-AA | 64 | D36 | CAM4\_PWDN/QUP14extra CS | – |
| – | CAM4\_PWDN | E37 | 145 | GPIO-Y | 45 | 46 | GPIO-BB | 27 | B47 | CAM5\_PWDN/BOOT\_CONFIG\_1 | – |

## Low-speed expansion connector 3

The low-speed expansion connector 3 provides the following functionalities:

- Four Qualcomm sensor core Qualcomm Universal Peripheral (QUP) interfaces. For more information about configuring I2C, SPI, UART, see <cite class="cite">Qualcomm Robotics RB5 Platform Software Porting Guide</cite> (80-88500-1).
- Interrupts signals for sensors.
- Additional GPIOs and power supplies.

The GPIOs labeled QUP have additional low-speed interface capabilities (UART, SPI, I2C). Several GPIOs can be used to wake up the application processor.

| Wake-up function | Additional info | SoM pin | GPIO | Signal | Pin number | Pin number | Signal | GPIO | SoM pin | Additional info | Wake-up function |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| – | CAM2\_STROBE | G22 | 100 | GPIO-KK | 1 | 2 | GPIO-TT | 10 | E36 | CAM4\_STROBE | – |
| – | PMIC | F41 | – | SLEEP\_CLK | 3 | 4 | CLK | – | B35 | PMK8002\_PMIC\_CLK | – |
| – | CAM3\_STROBE | J34 | 67 | GPIO-LL | 5 | 6 | GPIO-UU | 32 | C46 | CAM5\_STROBE | – |
| Yes | QUP19 | K32 | 0 | GPIO-MM | 7 | 8 | GPIO-YY | 115 | K40 | – | – |
| Yes | QUP19 | E39 | 1 | GPIO-NN | 9 | 10 | GPIO-ZZ | 70 | K42 | – | – |
| Yes | QUP19 | F38 | 2 | GPIO-OO | 11 | 12 | GPIO-VV | 88 | C40 | – | Yes |
| – | QUP7 | G40 | 22 | GPIO-AAA | 13 | 14 | GPIO-WW | 89 | C41 | – | Yes |
| Yes | QUP7 | G41 | 23 | GPIO-BBB | 15 | 16 | SPI3\_MISO | 172 | H43 | SSCQUP5 | – |
| Yes | – | G32 | 24 | GPIO-CCC | 17 | 18 | SPI3\_MOSI | 173 | H40 | SSCQUP5 | – |
| Yes | QUP19 | E38 | 3 | GPIO-PP | 19 | 20 | SPI3\_CLK | 174 | H41 | SSCQUP5 | – |
| – | QUP18 | G35 | 56 | GPIO-QQ | 21 | 22 | SPI3\_CS | 175 | H42 | SSCQUP5 | Yes |
| Yes | SSC QUP2 | J38 | 166 | SPI2\_CLK | 23 | 24 | PS\_INT | 129 | B41 | sensor int | Yes |
| – | SSC QUP2 | J41 | 165 | SPI2\_MOSI | 25 | 26 | ACCEL\_INT | 112 | J33 | sensor int | Yes |
| Yes | SSC QUP2 | J40 | 164 | SPI2\_MISO | 27 | 28 | GYRO\_INT | 113 | J32 | sensor int | Yes |
| Yes | SSC QUP2 | J39 | 167 | SPI2\_ACCEL\_CS | 29 | 30 | MAG\_INT | 122 | J29 | sensor int | Yes |
| – | SSC QUP2 | B2 | 168 | SPI2\_CS1 | 31 | 32 | MAG\_DRDY\_INT | 123 | K35 | sensor int | Yes |
| Yes | SSCQUP5 Extra CS | B7 | 162 | SPI3\_CS1 | 33 | 34 | I2C4\_SDA<br><br><br>                <br>(sensor) | 160 | J37 | SSCQUP0 | Yes |
| – | VREG\_L8C\_1P8 for sensors | B42 | – | **1.8 V-B** | 35 | 36 | I2C4\_SCL<br><br><br>                <br>(sensor) | 161 | H37 | SSCQUP0 | – |
| – | From onboard regulator |  | – | **5V** | 37 | 38 | **1.8V-C** | – | B43 | VREG\_L5C\_1P8 | – |
| – | VBATT\_CONN\_VSENSE\_P | H47 | – | **VBAT** | 39 | 40 | **GND** | – | – | – | – |
| – | VBATT\_CONN\_VSENSE\_M | G47 | – | **GND** | 41 | 42 | **GND** | – | – | – | – |
| – | QUP18 | F34 | 57 | GPIO-RR | 43 | 44 | SPI3\_CS2 | 163 | B8 | SSCQUP5 Extra CS | – |
| – | SSCQUP4/I2C\_SDA | H38 | 170 | GPIO-SS | 45 | 46 | GPIO-XX | 171 | H39 | SSCQUP4/I2S\_SCL | – |

**Parent Topic:** [RB5 mainboard connectors](https://docs.qualcomm.com/doc/80-88500-5/topic/rb5_mainboard_connectors.html)

Last Published: Nov 25, 2025

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