|Memory||1 or 2 GB|
|-30ºC to 80ºC|
Debian for Rhomb
Ubuntu for Rhomb
- 1 Overview
- 2 Board specifications
- 3 Connections
- 4 Schematics
- 5 Bill of materials
- 6 Fabrication files
- 7 Mechanical specifications
- 8 Warranty
- 9 Disclaimer
This sheet shows the documentation for the Gaia Rhomb.io board.
The Gaia board is the perfect tool designed for helping you to bring to the market your ideas and transform them in real products. This board helps you to explore the Rhomb.io modular hardware platform and to discover all its capabilities by bringing direct access to the more than 300 signals that conforms the standard Rhomb.io Cores. This board is the only tool that you need if you want to speed up your product design, test and validation stages.
The next figure show a 3D view for the Gaia board.
As a summary, the following table indicates the main features:
|Rhomb.io Core||All S400 core signals available|
|Rhomb.io Modules||1 x slot|
|USB||4 x USB type A 2.0|
|2 x USB type B (only power)|
|1 x USB OTG|
|SD||Micro SD card reader|
|Ethernet||10BASE-T and 100BASE-TX|
|Power supply||Battery or USB|
|J-TAG||ARM-20 J-TAG Header|
- Media center
The Gaia board has been designed to help you to convert your hardware and firmware projects on a product by using the rhomb modular platform. It gives access to more than 300 signals, all these coming from the Rhomb.io Cores, so this board is perfect not only for design, but for test and validate your products. But it is not limited only to that, it also includes a socket for standard Rhomb.io Modules, and offers a wide range of connectivity through USB, Ethernet, HDM, etc.
Check out the Block Diagram to understand what is under this PCB. Note that the power supply can be provided in two different ways, either by using a battery or by using directly a standard USB power source. This board also includes a J-TAG port, and 8 LEDs for giving feedback and to help on the product developing stage.
The following figures identify the main parts of the board. The most important parts will be explained with more detail in the next sections.
The Central Processing Unit (CPU), RAM, PMIC among other auxiliary elements are embedded on the core, a small standardized board designed to be connected on the core socket. Look on the description image to see where this socket is placed. On the following link you can find the currently available Rhomb.io Cores: Rhomb.io Shop.
Lots of Rhomb Modules focused in different areas such as communications, sensing or storage, are available. The Gaia board allows to connect one standard rhomb module. The description image on the "Key features" section shows where is placed the module socket to connect it. Look at here to choose the desired module in order to test it or to expand the capabilities of the Gaia board.
Two memory options are available for the Gaia board: a micro SD card and the Rhomb.io Memory eMMCXX Module. The eMMC memory modules used to be faster than the SD cards, but it occupies one module socket. The user should choose either one or other. In order to allow that, there is a switch array on the board that should be configured as it is shown on the two following images:
- eMMC bootloader configuration:
- Micro SD card bootloader configuration:
The DIP switches should not be moved unless the system is turned off.
The Gaia board has 4 USB 2.0 type A ports, all of them working as host. It includes also a micro USB type B connector that works as OTG. Note that there are two more micro USB type B connectors placed at the bottom side of the board; those two connectors are only for power purposes. See the "Power" section for more information regarding its functionality.
It is also available an Ethernet port that can carry traffic at the nominal rate of 100Mbit/s, supporting full and half-duplex with flow control. Look at the image below to identify each connector on the board.
The Gaia board is fully compliant with the HDMI audio and video interface. The next figure shows where the HDMI type A connector is placed on the board.
Switch, Buttons and LEDs
The Switch ON is used to cut the power input. When the switch is ON, connects VSYS* with VSYS. When the Power Management Integrated Circuit (PMIC) on the core receives VSYS it is ready to generate all the voltages needed for the entire circuitry. For more details, look at the "Schematics" sections.
The Gaia board also include two buttons: the Button RST and the Button ON. The first one resets the PMIC and, consequently the system. The second is used to turn on the PMIC and the processor.
A total of 8 LEDs are assembled on the Gaia board in order to give status feedback to the user. The functionality of each one of them is explained on the following table:
|LDO-F ON||Turned on when the power supply line named LDO-F is ready|
|BUCK-A ON||Turned on when the power supply line named BUCK-A_3V3 is ready|
|LDO21 ON||Turned on when the power supply line named VDDIO_MODA is ready|
|VSYS||Shines when the main power supply source on the board (VSYS) is working|
|LED1||LED free to use connected to the GPIO03. By fault configured as heartbeat|
|LED2||LED free to use connected to the GPIO02. By default indicates memmory activity|
|LED3||LED free to use connected to the GPIO01. By default indicates CPU activity|
|LED4||LED free to use connected to the GPIO00. By default indicates LAN activity|
The LDO-F ON, BUCK-A ON and LDO-Q ON LEDs are intended to give to the user a feedback about the booting sequence. The LDO-F ON and the LDO-Q ON LEDs indicates that the Power Management Integrated Circuit (PMIC) on the core board is ok. These LEDs will be turned on once the Switch ON is on and the Button ON is pressed about two seconds. After a few more seconds, the BUCK-A ON LED will be turned on, meaning that the processor is on the initializing stage. Once this sequence has been done, the three LEDs will be always shining unless the user modify the configuration of the PMIC.
The LED1, LED2, LED3 and LED4 LEDs have been configured as is indicated on the table, but those LEDs are free to use. Force to high level the corresponding GPIO to make the LED shine.
The Gaia board can be used for designing, testing and validate the product, for this reason the board includes a standard ARM 2x10 pin JTAG connector. In addition to that, it's been provided easy access to the UART-B and UART-D by means of standard 2.54 mm headers. As the Rhomb.io standard defines, the UART-B is the interface used for the system debugging. The UART-D can be used according to the user needs.
The Gaia board has been designed for giving to the user a functional and useful tool for product developing and testing, for this reason on this board all the signals providing from the Rhomb.io Core has been expanded to accessible-size headers in the same order as in the core socket. The following image shows how are interconnected the pinout from the core socket with the expansion headers.
As an example, the pin 16 on the connector J408 is tied to the pin 16 on the header J8_HDR. This pin is used in order to reset the PMIC on the Rhomb.io Core and, as a result, resets the system. Force the pin 16 to zero on the J8_HDR header to see that the resets happens. Look at the "Schematics" section to identify the mentioned connectors.
The following table summarizes the GPIOs used on the Gaia board. Unless specific indications, all the signals are active high.
|06||MOD_RESET||Resets the Rhomb.io Module||27|
|07||MOD1_GPIO0||Module 1 socket, GPIO0||28|
|08||MOD1_GPIO1||Module 1 socket, GPIO 1||29|
|09||MOD1_GPIO2||Module 1 socket, GPIO 2||30|
|10||MOD1_GPIO3||Module 1 socket, GPIO 3||31|
|11||MOD1_GPIO4||Module 1 socket, GPIO 4||32|
|12||MOD1_GPIO5||Module 1 socket, GPIO 5||33|
|13||MOD1_GPIO6||Module 1 socket, GPIO 6||34|
|14||MOD1_GPIO7||Module 1 socket, GPIO 7||35|
|15||36||ChargMangmnt_!EN||Enables the battery charger. Active low.|
|16||37||ChargMangmnt_!POK||Power input for the battery charger is ok. Active low|
|17||38||SPI-A_CS1||Chip select 1 of SPI-A bus|
|18||39||SPI-A_CS2||Chip select 2 of SPI-A bus|
For more details, look at the specifications for the Rhomb.io standard.
The following table summarizes the signals that can cause interrupts on the Rhomb.io Core.
|00||MOD1_INT||Interrupt on the Rhomb.io Module||08|
|05||13||CEC_HDMI||HDMI Consumer Electronics Control|
|07||HPD_HDMI||HDMI Hot Plug Detect||15||XEINT15||System Power ON|
The following tables indicates the use of the available serial interfaces on the Rhomb.io standard. For more details, look at the specifications for the Rhomb.io standard.
The I2C1 has two pull-up resistors at 4.7kΩ connected to VDDIO.
This interface is not used on the Gaia board.
|D||Rhomb.io Module, debug headers|
As the Rhomb.io standard defines, the UART-B is the interface used for the system debugging. Note that both the UART-B and the UART-D are easily accessible by means of standard 2.54mm headers. The UART-D can be used according to the user needs.
|C||USB HUB and Ethernet|
|OTG||Micro USB-B connector|
The next table shows how the Secure Digital Input Output (SDIO) interfaces are connected on the Gaia board.
For more details, look at the specifications for the Rhomb.io standard.
The Block Diagram shows that the power supply could be provided through the two micro USB type B connectors or from a Li-Ion battery. A switching circuit is responsible to drive the current according to the existing power input. The "Main PWR USB" is the main power supply and feeds all the circuitry. The "Secondary PWR USB" is a secondary source power that feeds the four USB type A connectors. This should be used when the devices connected there needs more power than the "Main PWR USB" is capable to supply. Note that the data lines are not connected to the micro USB B connectors, are used only as a power supply connectors.
When the power is supplied trough the USB connector, the power adapter should be able to supply 2A of output current, as a minimum.
If a battery is used, it should be connected according to the polarity indicated on the board, where the symbol "+" indicates the positive terminal. The system supports only single cell Li-Ion batteries and it will start to charge when a power supply is connected to the "Main PWR USB" USB B connector. The charging current ranges from 15 to 500 mA. You can adjust it with potentiometer P1 following the next formula:
Ichrg(mA) = 1000V/(2k+P1)ohm
There is also a fuel gauge IC on the board that is controlled trough the I2C-A. Look at the manufacturer documentation (MAX8814ETA+T) to discover the amount of parameters that is capable to measure. When the battery voltage drops under 3.3V, a battery protection circuit cuts the input battery current in order to prevent the deep discharge.
The following table summarizes the power supply signals on the Gaia board and indicates where are used.
|Signal||Voltage (V)||Used by||Signal||Voltage (V)||Used by|
|Battery charger IC||LDO-E|
|VSYS||3 - 5.5||Rhomb.io Core||LDO-F||2.8||Micro SD|
|LEDs (all)||LDO-I||3.0||USB HUB/Ehernet|
For more details, look at the specifications for the rhomb standard.
On the following table it is shown how the Analog to Digital, PWM and CLK signals are connected on the Gaia board.
|Analog to Digital|
|CLK 32.768 kHz|
For more details regarding these signals, look at the specifications for the Rhomb.io standard.
Bill of materials
- Precaution against Electrostatic Discharge. When handling Rhomb.io products, ensure that the environment is protected against static electricity. Follow the next recommendations:
- The users should wear anti-static clothing and use earth band when manipulating the device.
- All objects that come in direct contact with devices should be made of materials that do not produce static electricity that would cause damage.
- Equipment and work table must be earthed.
- Ionizer is recommended to remove electron charge.
- Contamination. Be sure to use semiconductor products in the environment that may not be exposed to dust or dirt adhesion.
- Temperature/Humidity. Semiconductor devices are sensitive to environment temperature and humidity. High temperature or humidity may deteriorate semiconductor devices characteristics. Therefore avoid storage or usage in such conditions.
- Mechanical Shock. Care should be exercised not to apply excessive mechanical shock or force on the connectors and semiconductors devices.
- Chemical. Do not expose semiconductor device to chemical because reaction to chemical may cause deterioration of device characteristics.
- Light Protection. In case of non-EMC (Epoxy Molding Compound) package, do not expose semiconductor IC to strong light. It may cause devices malfunction. Some special products which utilize the light or have security function are excepted from this specification.
- Radioactive, Cosmic and X-ray. Semiconductor devices can be influenced by radioactive, cosmic ray or X-ray. Radioactive, cosmic and X-ray may cause soft error during device operation. Therefore semiconductor devices must be shielded under environment that may be exposed to radioactive, cosmic ray or X-ray.
- EMS (Electromagnetic Susceptibility). Note that semiconductor devices characteristics may be affected by strong electromagnetic waves or magnetic field during operation.
Rhomb.io reserves the right to make corrections, enhancements, improvements and other changes to its products and services, and to discontinue any product or service. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All the hardware products are sold subject to the Rhomb.io terms and conditions of sale supplied at the time of order acknowledgment.
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