This manual provides comprehensive instructions on how to use the SP7350 IO Board. The SP7350 IO Board, when combined with the Core Board, serves as a demonstration platform for showcasing the hardware and software capabilities of the SP7350. Additionally, it offers customers a robust environment to develop their own software and applications.
For Chinese language users, a corresponding version of this documentation is available in the PDF file named "SP7350_IO_Board使用手册v1.1".
Table of Contents
1. Description of Main Equipment or Interfaces
Refer to the photo below, which shows the IO Board with the Core Board mounted on it:
The table below describes:
Item | Description |
1 | 12V DC power input. The DC Jack plug diameter is 5.5mm, and the adapter power supply current must be greater than 1A. |
2 | Ethernet RJ-45 socket, supports 10M/100M/1000M transmission. |
3 | Ethernet Giga PHY, Realtek RTL8211FD chip. |
4 | HDMI output interface, supports 1080P, 720P, 480P. |
5 | MIPI/DSI to HDMI bridge chip, LT8912B |
6 | 4-pole, 3.5mm, TRRS headphone jack, Apple type (L, R, G, M). |
7 | Analog microphone input. |
8 | Audio output, can only output either to headphones or speakers. |
9 | Audio codec chip, ES8316 |
10 | Wake-up button. Functions as follows:
|
11 | Reset button, resets CM4 and MAIN-DOMAIN Power, but cannot reset RTC. |
12 | USB3.1 Type C socket, supports Low/Full/High/Super speeds. Please note, USB3.1 Type A and Type C are multiplexed, and both interfaces cannot be used simultaneously. |
13 | Serial port Type C socket, supports UA0/UA6/UADBG 3 serial ports through jumper switch from Type C output. |
14 | CH340 USB to serial chip. |
15 | Dual USB3.1 Type A socket, supports Low/Full/High/Super speeds. |
16 | Dual USB3.1 Type A socket, supports Low/Full/High/Super speeds. |
17 | 4-port USB3.1 Gen. 1 Hub chip, VL817-Q7S |
18 | SPI-NOR flash chip, MX25L512, used with USB3 hub chip. |
19 | Dual USB2.0 Type A socket, supports Low/Full/High speeds. |
20 | Dual USB2.0 Type A socket, supports Low/Full/High speeds. |
21 | 4-port USB2.0 Hub chip, SPD104 |
22 | EEPROM chip, used with USB2 Hub chip. |
23 | M.2 E-key interface SDIO wireless network card. Refer to Appendix I for pin definitions. |
24 | MIPI2-RX interface, 22-pin, 0.5mm, top-contact FFC connector (not supported in version A chip). |
25 | MIPI3-RX interface, Raspberry Pi 15-pin, 1.0mm camera FFC connector compatible. Refer to section 8.2 for pin definitions. |
26 | MIPI5-RX interface, 22-pin, 0.5mm, top-contact FFC connector. Refer to section 8.4 for pin definitions. |
27 | MIPI4-RX interface, Raspberry Pi 15-pin, 1.0mm camera FFC connector compatible. Refer to section 8.3 for pin definitions. |
28 | MIPI-TX (1c2d) interface, Raspberry Pi 15-pin, 1.0mm display FFC connector compatible. Refer to section 8.6 for pin definitions. |
29 | MIPI-TX (1c4d) interface, 30-pin, 0.5mm, top-contact FFC connector. Refer to section 8.5 for pin definitions. Note: Both MIPI-TX connectors share signals with the HDMI interface; all 3 interfaces cannot be used simultaneously. |
30 | KEY button detection. Refer to section 7 for details. |
31 | SP7350 boot configuration switch. Refer to section 3 for details. |
32 | Micro SD card socket. |
1.1. Explanation of pins or jumpers.
The table below describes:
Items | Descriptions | Remarks |
1 | HDMI/MIPITX selection jumper | Refer to section 7 |
2 | Pin-header (2x13, 2.0mm) of LVDS output of LT8912B | Refer to Appendix II |
3 | USB3 Type-C and Type-A (all 4 ports) selection jumper | Refer to section 6 |
4 | UA0/UA6/UADBG output, and selecting serial port via USB | Default is UA0 tol USB |
5 | USB2.0 hub debug serial port | Default not connected |
6 | Selecting GPIO output level selection (1.8V/3.3V). | Default 3.3V output |
7 | Reserved IO ports | Refer to section 5 |
8 | Plug a jumper in to turn on power automatically. Otherwise, required to press wake-up key to turn on power. | Default short circuit |
9 | Fan power supply, speed configured via I2C |
|
10 | 12V DC power supply |
|
2. Boot Devices and Configurations
The SP7350 IO board supports booting either from eMMC or an SD card.
3.1. eMMC Boot
To initiate booting from eMMC, configure the boot switch as [1 1 1 1]. Please refer to Figure 3 for visual guidance.
The eMMC chip is situated on the Core board, indicated by the red rectangle. For precise location, consult Figure 4 below.
3.2. SD Card Boot
For booting from an SD card, set the boot switch to [1 1 0 0]. For assistance, refer to Figure 5.
Insert your SD card into the micro SD card socket, as demonstrated in Figure 6.
3.3. Boot Configuration Switch Definitions
Table 3 outlines the interpretation of boot configuration switch settings.
Boot Devices | Boot Configuration Switch | |||
1 | 2 | 3 | 4 | |
eMMC Boot | 1 | 1 | 1 | 1 |
SDC Boot / ISP | 1 | 1 | 0 | 0 |
USB ISP | 1 | 1 | 0 | 1 |
In the above table, “1” signifies switch OFF, while “0” indicates switch ON.
4. In-System Program (ISP)
The SP7350 chip supports in-system programming (ISP) of the eMMC device. Users can copy the compiled output file (ISPBOOOT.BIN, ISPBOOT1.BIN, …) to a USB drive or SD card and directly program it onto the eMMC device. The programming process is as follows:
4.1. ISP from an SD card
For ISP from an SD card, set the boot switch to [1 1 0 0]. Refer to Figure 7.
Copy the compiled eMMC output file ISPBOOOT.BIN (ISPBOOT1.BIN, ISPBOOT2.BIN, …) to the SD card and insert the SD card into the Micro SD card slot as shown in the figure 8 below:
Power on the system, and the system will automatically program the images into the eMMC device.
4.2. ISP from a USB flash drive
For ISP from a USB flash drive, set the boot switch to [1 1 0 1]. Refer to Figure 9.
Copy the compiled eMMC output file ISPBOOOT.BIN (ISPBOOT1.BIN, ISPBOOT2.BIN, …) to a USB flash drive (should be formatted as FAT32) and insert the USB flash drive into the USB3 Type-C socket (refer to section 6 for the use of USB3 Type-A).
After powering on, the system will automatically program the images into the eMMC device.
5. Configuring GPIO Voltage
The SP7350 IO board supports 22 GPIO pins that can be configured for either 1.8V or 3.3V output voltage. These GPIO pins can be utilized individually for general-purpose input/output (GPIO) functions or configured for specific functionalities such as SPI/I2C/UART, among others. For detailed configurations, please refer to the pinmux table. The GPIO wiring diagram for CN16/CN17 is provided below:
GPIO output voltage is configured as follows:
Jumper | GPIO Output Voltage |
 | 1.8V |
 | 3.3V |
6. USB3 Type-A and Type-C Selection
USB3 supports one Type C port or four Type A ports (through a 4-port USB3.0 Hub).
USB3.0 can be selected to use either 4 Type-A ports or Type-C port via a jumper.
Jumper | Ports |
 | USB3.0 Type-C |
 | USB3.0 Type-A |
7. HDMI and MIPI-TX Selection
The MIPI-TX can be selected to output using either HDMI or MIPI DSI.
HDMI: A MIPI/DSI-to-HDMI bridge chip, LT8912B is used to convert MIPI DSI signal to HDMI.
MIPI DSI: The MIPI-TX of SP7350 is routed to an FFC connector for external connections directly.
HDMI and MIPI DSI cannot be used simultaneously because they share the same MIPI DSI source from SP7350. A jumper is used to select to output to HDMI or MIPI DSI, as outlined below:
Jumper | Output |
 | HDMI |
 | MIPI DSI (30-pin or 15-pin FFC) |
8. MIPI
8.1. MIPI-RX2
Note version A of SP7350 does not support this channel.
MIPI-RX2 is connected to a Raspberry Pi camera compatible, 22-pin, 0.5mm FFC connector. For pin definitions of the FFC connector, please refer to Figure 16.
Jumpers are required across GPIO74, GPIO75, GPIO77, and GPIO76 on CN17, as depicted in Figure 17:
8.2. MIPI-RX3
MIPI-RX3 is connected to a Raspberry Pi camera compatible, 15-pin, 1.0mm FFC connector. For pin definitions of the FFC connector, please refer to Figure 18.
Jumpers need to be placed across GPIO70, GPIO71, GPIO72, and GPIO73 on CN17, as illustrated in Figure 19:
8.3. MIPI-RX4
MIPI-RX3 is connected to a Raspberry Pi camera compatible, 15-pin, 1.0mm FFC connector. For pin definitions of the FFC connector, please refer to Figure 20.
Jumpers are required across GPIO63, GPIO19, GPIO68, and GPIO69 on CN16, as depicted in Figure 20:
8.4. MIPI-RX5
MIPI-RX5 is connected to a Raspberry Pi camera compatible, 22-pin, 0.5mm FFC connector. For pin definitions of the FFC connector, please refer to Figure 22.
Jumpers are required across GPIO61, GPIO60, GPIO85, and GPIO84 on CN16, as depicted in Figure 23:
8.5. MIPI-TX (4d1c)
MIPI-TX (4d1c)5 is connected to a Forlinx LT8912B MIPI-to-HDMI Bridge Board Compatible, 30-pin, 0.5mm FFC connector. For pin definitions of the FFC connector, please refer to Figure 24.
Jumpers are required across GPIO78, GPIO79, GPIO88, GPIO89, GPIO91, and GPIO90 on CN16, as depicted in Figure 25:
Note that the MIPI-TX (4d1c), MIPI-TX (2d1c), and HDMI outputs all share the same input source. Therefore, these three interfaces cannot be used simultaneously.
8.6. MIPI-TX (2d1c)
MIPI-TX (2d2c) is connected to a Raspberry Pi display compatible, 15-pin, 1.0mm FFC connector. For pin definitions of the FFC connector, please refer to Figure 26.
Jumpers are required across GPIO91, and GPIO90 on CN16, as depicted in Figure 27:
Note that the MIPI-TX (4d1c), MIPI-TX (2d1c), and HDMI outputs all share the same input source. Therefore, these three interfaces cannot be used simultaneously.
9. Keys
The SP7350 IO Board has 3 key buttons that can trigger different software functions when pressed.
The SP7350 IO Board uses one ADC channel to detect the three key buttons. When a key is pressed, the corresponding ADC input voltage changes. The schematic is shown below:
The software can determine which key is pressed based on the ADC sample values of the input voltage:
ADC Sample Value | Key Pressed |
0V | KEY1 |
0.9V | KEY2 |
1.2V | KEY3 |
1.8V | No Key Pressed |
10. Serial Ports
The SP7350 IO Board includes three UART ports: UART6, UART0, and UADBG. Each UART port can connect to a UART terminal (a PC) via a 3-pin, 100-mil pitch pin-header, as illustrated in Figure 30. The pin-out for each pin-header, from left to right, is GND, RX, and TX. All signals are 3.3V.
The SP7350 IO Board also supports UART to USB2.0 conversion using the CH340N bridge chip. This enables one serial port to connect directly to a PC via a USB2.0 Type-C cable. Refer to the table below for connecting a UART port to the UART-to-USB bridge. Connecting one UART port requires plugging in two jumpers.
 |  |  |
Connect UA6 to Type-C. | Connect UA0 to Type-C. | Connect UADBG to Type-C. |
Note:
Only one UART can be connected to the UART-to-USB bridge at a time.
Before using the CH340N, you need to download and install its driver.
11. Appendix I Pin Definitions of Wireless Network Module
The pin definitions of the wireless (M.2 E-key) module are as follows:
12. Appendix II Pin Definitions of LVDS Output of LT8912B
