UART1 boot console
UART1 is the board’s logic-level console, with ground on U14-1. U14-3 · UART1-TX, U14-5 · UART1-RX.
Next Thing Co. C.H.I.P. pinout
Original C.H.I.P. single-board computer with an Allwinner R8, USB OTG, display and camera interfaces and an I²C GPIO expander.
Next Thing Co. C.H.I.P.
80 contacts Current packageNext Thing Co. C.H.I.P. pinout
U13 left header
U14 right header
U14-1 · GND
Board ground return.
All 80 pins
| Pin | Signal | Direction | Function |
|---|---|---|---|
| U13-1 | GND Return | Return | Board ground return. |
| U13-2 | CHG-IN Power input | Power input | 5 V charge input to the power-management circuit. Use Micro-USB for the bench examples. |
| U13-3 | VCC-5V Supply rail | Supply rail | Board power rail. Verify the correct voltage and available current before attaching a load. |
| U13-4 | GND Return | Return | Board ground return. |
| U13-5 | VCC-3V3 Supply rail | Supply rail | Board power rail. Verify the correct voltage and available current before attaching a load. |
| U13-6 | TS Analog input | Analog input | Analog input. Follow the associated input range and reference circuit in the board documentation. |
| U13-7 | VCC-1V8 Supply rail | Supply rail | Board power rail. Verify the correct voltage and available current before attaching a load. |
| U13-8 | BAT Power input | Power input | Battery connection to the power-management circuit. Follow the manufacturer battery specification and polarity. |
| U13-9 | TWI1-SDA Multiplexed | Multiplexed | Part of a board peripheral interface. Follow the signal assignment and I/O voltage. |
| U13-10 | PWRON Board control | Board control | Use the board-specific control circuit. Leave this contact alone during normal power and serial setup. |
| U13-11 | TWI1-SCK Multiplexed | Multiplexed | Part of a board peripheral interface. Follow the signal assignment and I/O voltage. |
| U13-12 | GND Return | Return | Board ground return. |
| U13-13 | X1 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U13-14 | X2 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U13-15 | Y1 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U13-16 | Y2 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U13-17 | LCD-D2 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-18 | PWM0 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-19 | LCD-D4 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-20 | LCD-D3 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-21 | LCD-D6 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-22 | LCD-D5 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-23 | LCD-D10 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-24 | LCD-D7 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-25 | LCD-D12 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-26 | LCD-D11 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-27 | LCD-D14 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-28 | LCD-D13 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-29 | LCD-D18 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-30 | LCD-D15 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-31 | LCD-D20 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-32 | LCD-D19 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-33 | LCD-D22 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-34 | LCD-D21 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-35 | LCD-CLK Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-36 | LCD-D23 Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-37 | LCD-VSYNC Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-38 | LCD-HSYNC Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U13-39 | GND Return | Return | Board ground return. |
| U13-40 | LCD-DE Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U14-1 | GND Return | Return | Board ground return. |
| U14-2 | VCC-5V Supply rail | Supply rail | Board power rail. Verify the correct voltage and available current before attaching a load. |
| U14-3 | UART1-TX Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U14-4 | HPL Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U14-5 | UART1-RX Input / mux | Input / mux | Receive input in the named UART mode. Use a 3.3 V logic-level endpoint for the bench example. |
| U14-6 | HPCOM Analog reference | Analog reference | Headphone output reference. Follow the board audio circuit. |
| U14-7 | FEL Board control | Board control | Use the board-specific control circuit. Leave this contact alone during normal power and serial setup. |
| U14-8 | HPR Output / mux | Output / mux | Output in the named peripheral mode. Check board pinmux before use. |
| U14-9 | VCC-3V3 Supply rail | Supply rail | Board power rail. Verify the correct voltage and available current before attaching a load. |
| U14-10 | MICM Board control | Board control | Use the board-specific control circuit. Leave this contact alone during normal power and serial setup. |
| U14-11 | LRADC Analog input | Analog input | Analog input. Follow the associated input range and reference circuit in the board documentation. |
| U14-12 | MICIN1 Analog input | Analog input | Analog input. Follow the associated input range and reference circuit in the board documentation. |
| U14-13 | XIO-P0 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-14 | XIO-P1 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-15 | XIO-P2 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-16 | XIO-P3 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-17 | XIO-P4 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-18 | XIO-P5 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-19 | XIO-P6 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-20 | XIO-P7 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-21 | GND Return | Return | Board ground return. |
| U14-22 | GND Return | Return | Board ground return. |
| U14-23 | AP-EINT1 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-24 | AP-EINT3 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-25 | TWI2-SDA Multiplexed | Multiplexed | Part of a board peripheral interface. Follow the signal assignment and I/O voltage. |
| U14-26 | TWI2-SCK Multiplexed | Multiplexed | Part of a board peripheral interface. Follow the signal assignment and I/O voltage. |
| U14-27 | CSIPCK Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-28 | CSICK Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-29 | CSIHSYNC Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-30 | CSIVSYNC Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-31 | CSID0 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-32 | CSID1 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-33 | CSID2 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-34 | CSID3 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-35 | CSID4 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-36 | CSID5 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-37 | CSID6 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-38 | CSID7 Multiplexed | Multiplexed | Board connector signal. Enable its peripheral or GPIO function in the operating system when the board supports it. |
| U14-39 | GND Return | Return | Board ground return. |
| U14-40 | GND Return | Return | Board ground return. |
Signal assignments
TWI1 / I²C
Connect a 3.3 V peripheral and use the correct Linux adapter. U13-9 · TWI1-SDA, U13-11 · TWI1-SCK.
TWI2 / I²C
The onboard XIO expander occupies address 0x38 on TWI2. U14-25 · TWI2-SDA, U14-26 · TWI2-SCK.
XIO expander
The XIO pins are controlled through the TWI2 expander. U14-13 · XIO-P0, U14-14 · XIO-P1, U14-15 · XIO-P2, U14-16 · XIO-P3, U14-17 · XIO-P4, U14-18 · XIO-P5, U14-19 · XIO-P6, U14-20 · XIO-P7.
Electrical limits
| Parameter | Limit | Conditions and source |
|---|---|---|
| Micro-USB supply5 V, 1 A minimum recommended | 5 V, 1 A minimum recommended | Use an adequately rated cable and source to avoid voltage sag during boot. Next Thing Co. C.H.I.P. Hardware and Pin Headers |
| UART console fixture3.3 V logic | 3.3 V logic | Connect RX, TX and ground only. Next Thing Co. C.H.I.P. Hardware and Pin Headers |
| TWI2 reserved address0x38 | 0x38 | Reserved by the onboard XIO expander. Next Thing Co. C.H.I.P. Hardware and Pin Headers |
Models and documents
Covers both original C.H.I.P. board headers, U13 and U14. Use the board’s orientation diagram before counting contacts.
- Next Thing Co. C.H.I.P.
- Allwinner R8 · two 40-position headers U13 and U14
- Next Thing Co. C.H.I.P. documentation· Archived manufacturer guide for U13 and U14, board power, TWI and serial console.
- C.H.I.P. hardware source· Manufacturer hardware repository with the board design files.
- Single-board computer source register· Applicability, retrieval dates, source URLs and SHA-256 digests.