Phobos

Phobos Board  

  Top view
 
The Phobos board is a certified Rhomb.io PCB that allows to create electronics devices using exclusively standard Rhomb.io modules. It combines the ease-of-use Rhomb.io standard modules with a reduced form factor PCB, and it has been developed for the Internet of Things (IoT) bearing in mind the fast product development. The board includes also a battery management circuit bringing to the designer the capacity to made portable devices.

The Phobos board it has been designed for working only with Rhomb.io standard modules, so a Rhomb.io core is not needed. Two standard Rhomb.io modules holders are available, one for the master module and another for the slave. That brings simplicity and speed up the product designing and development stage.

 

Key Features
CPU Master module
Memory  According to master module
GPU N/A
Video output  N/A
Storage

According to

master module

Network N/A;
I2C available
SPI available
UART   x1
USB  x1 type B 
 Dimensions 37x50x8,763 (mm) 

Temperature

range 

 -30ºC to 80ºC
Operating Systems 

Debian for Rhomb

Ubuntu for Rhomb

Buildroot

Lubuntu

            Bottom view

 



centro
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This sheet shows the documentation for the Phobos Rhomb.io board.

Preliminary version, use only for data updating or corrections.


Overview

The Phobos board is a certified Rhomb.io PCB that allows to create electronics devices using exclusively standard Rhomb.io modules. It combines the ease-of-use Rhomb.io standard modules with a reduced form factor PCB, and it has been developed for the Internet of Things (IoT) bearing in mind the fast product development. The board includes also a battery management circuit bringing to the designer the capacity to made portable devices.

The next figures show a 3D view for the Phobos board.

Phobos 3D Top v3.png Phobos 3D Bottom v3.png

[Arturo V. tiene que revisar la imagen]

As a summary, the following table indicates the main features:

Phobos features
USB 1 USB type B
Expansion headers 40 pines
Rhomb.io modules 1 Master Module slot
1 Generic Module slot

Applications:

  • Internet of Things
  • Wearables
  • Makers
  • Fast prototyping


Board specifications

The Phobos board it has been designed for working only with Rhomb.io standard modules, so a Rhomb.io core is not needed. Two standard Rhomb.io modules holders are available, one for the master module and another for the slave. That brings simplicity and speed up the product designing and development stage.

There are two different ways to empower the system: using the micro-USB connector or a battery. The PCB also includes a Lithium battery charge management controller bringing the capacity to work independently of the power supply.

As a summary, here are the key features for the Phobos board:

  • Capacity for holding two Rhomb.io modules: master and slave
  • There is no need for a Core
  • Compatibility with all the Rhomb.io modules
  • Fast prototyping
  • USB connector for data and power supply
  • In-circuit battery management
  • Small form factor

The block diagram shows the parts that make it possible.

Phobos Block Diagram v4.png

The following figure identify the main parts of the board. The most important parts will be explained with more details in the next sections.

Phobos Description Top v5.png Phobos Description Bottom v4.png

[Arturo V. tiene que revisar la imagen]


Rhomb.io Core

The Phobos board has no core sockets.

Rhomb.io modules

Lots of Rhomb.io modules focused in different areas such as communications, sensing or storage, are available. The Phobos board allows to connect a one Rhomb.io master module and one slave module. Look at here [Añadir enlace a la tienda, sección modulos] to chose the desired module to convert your Phobos in the device you want.

Memory

Only one memory options is available in the Phobos board: a Memory eMMCXX Module.

Connectivity

Wired

There is available one USB 2.0 port on the Phobos board and it work as a host for the master module. It is also three headers with a total of 40 pins that allow to access to some Rhomb.io master module signals. The following table shows the pinout of the headers.

H1
Pin Function
1 3V3
2 2V8
3 1V8
4 GND
5 RESET
6 IO16 (SPI SS)
7 SPI0_SCK
8 SPI0_MISO
9 SPI0_MOSI
10 SCL0
11 SDA0
12 IO32 (1-wire)
H2
Pin Function
1 TXD1
2 RXD1
3 TXD0
4 RXD0
5 AD0
6 AD1
7 AD2
8 AD3
9 IO0
10 IO1
11 IO2
12 IO3
13 IO4
14 IO5
15 IO6
16 IO7
H3
Pin Function
1 IO8
2 IO9
3 IO10
4 IO11
5 IO12
6 IO13
7 IO14
8 IO15
9 VDDIO_MOD
10 VSYS
11 VBAT
12 GND

Phobos Wired v1.png

[Arturo V. tiene que revisar la imagen]

Wireless

The Phobos board has nos wireless interfaces.


Video/Audio

The Phobos board has nos audio and video interfaces.

LEDs and Button

The two available LEDs onboard are intended to indicate the battery charging status. The orange LED will bright when the USB charging source is connected in order to indicate that the battery is being charging. When the process finishes, the orange LED turns off and the green one turns on. When the USB cabled is disconected, the two LEDs turns off. In any case, if the battery is disconnected, the LEDs will not work.

There is no buttons assembled on the Phobos board.

Phobos LEDsandButtons v1.png

[Arturo V. tiene que revisar la imagen]


Connections

Master module auxialiary connectors

The following table summarizes the standard signals of the Rhomb.io master module socket and where they are used in the Phobos. These signals may not have functionality depending of the microcontrolled plugged on the board.

J4
Pin Signal Used by Pin Signal Used by
1 IO47, SDA1 50 IO0 H2 pin 9, Slave Module GPIO0
2 IO46, SCL1 49 IO1 H2 pin 10, Slave Module GPIO1
3 IO45, LPUART.RX/RXD2, SPIFI_IO3 48 IO2 H2 pin 11, Slave Module GPIO2
4 IO44, LOPUART.TX/TX2, SPIFI_IO2 47 IO3 H2 pin 12, Slave Module GPIO3
5 IO43, SPI1_MOSI, SPIFI_IO1 46 IO4 H2 pin 13, Slave Module GPIO4
6 IO42, SPI1_MISO, SPIFI_IO2 45 IO5 H2 pin 14, Slave Module GPIO5
7 IO41, SPI1_CLK, SPIFI_CLK 44 IO6 H2 pin 15, Slave Module GPIO6
8 IO40, SPI1_SS, SPIFI_CS 43 IO7 H2 pin 16, Slave Module GPIO7
9 GND GND 42 GND GND
10 IO39, TMS/SWDIO 41 IO8 H3 pin 1
11 IO38, TCK/SWCLK 40 IO9 H3 pin 2
12 IO37, TDO/SWO 39 IO19 H3 pin 3
13 IO36, TDI 38 IO11 H3 pin 4
14 1V8 1.8 V 37 IO12 H3 pin 5
15 2V8 2.8 V 36 IO13 H3 pin 6
16 35 IO14 H3 pin 7
17 3V3 3.3 V 34 IO15 H3 pin 8
18 33 VSYS VSYS
19 32
20 VIO_REF H3 pin 9, Slave Module VDDIO_MOD 31
21 AREF 30 GND GND
22 GND GND 29 AD0 H2 pin 5, Slave Module AD_OUT
23 AD14 28 AD1 H2 pin 6
24 AD13 27 AD2 H2 pin 7
25 AD12 26 AD3 H2 pin 8
J3
1 AD11 50 AD4
2 AD10 59 AD5
3 AD9 48 AD6
4 AD8 47 AD7
5 GND GND 46 GND GND
6 IO35, TRST 45 RXD0 H2 pin 4, Slave Module UART0_RXD
7 IO34, CAN1_RX Slave Module SPI_INT 44 TXD0 H2 pin 3, Slave Module UART0_TXD
8 IO33, CAN1_TX Slave Module I2C_INT 43 RXD1 H2 pin 2
9 IO32, 1-WIRE/SWP H1 pin 12 42 TXD1 H2 pin 1
10 USB2_P Slave Module USB 41 SDA0 H1 pin 11, Slave Module I2C_SDA
11 USB2_N 40 SCL0 H1 pin 10, Slave Module I2C_SCL
12 USB_ID 39 SPI0_MOSI H1 pin 9, Slave Module SPI_MOSI
13 CLK_32KHz Slave Module CLK_32KH 38 SPI0_MISO H1 pin 8, Slave Module SPI_MISO
14 BAT_RTC 37 SPI0_SCK H1 pin 7, Slave Module SPI_SCK
15 VBAT VBAT 36 SPI0_SS Slave Module SPI_SS
16 35 RESET H1 pin 5
17 34 GND GND
18 IO31, SDIO0_DATA1 Slave Module SDIO0_DATA1 33 IO16, I2S_SDI H1 pin 6
19 IO30, SDIO0_DATA0 Slave Module SDIO0_DATA0 32 IO17, I2S_SDO, SDIO1_DATA1 Slave Module SDIO1_DATA1
20 IO29, SDIO0_CLK Slave Module SDIO0_CLK 31 IO18, I2S_SCLK, SDIO1_DATA0 Slave Module SDIO1_DATA0
21 IO28, SDIO0_CDN Slave Module SDIO0_CLK 30 IO19, I2S_LRCK, SDIO1_CLK Slave Module SDIO1_CLK
22 IO27, SDIO0_CMD Slave Module SDIO0_CMD 29 IO20, I2S_CDCLK, SDIO1_CDN Slave Module SDIO1_CDN
23 IO26, SDIO0_DATA3 Slave Module SDIO0_DATA3 28 IO21, CAN2_RX, SDIO1_CMD Slave Module SDIO_CMD
24 IO25, SDIO0_DATA2 Slave Module SDIO0_DATA2 27 IO22, CAN2_RX, SDIO1_DATA3 Slave Module SDIO1_DATA3
25 IO24, DAC1 26 IO23, DAC0, SDIO1_DATA2 Slave Module SDIO1_DATA2

Regarding the serial interfaces, two issues should be mentioned. The USB data lines comes from the micro USB type B connector to the master socket. For the I2C interface, the board provides two pull-ups resistors (R4 and R5). Those pull-ups are defined as normally not connected to the supply. If it is needed to use them, the user should solder the onboard solder jumper that will connect the power supply with the resistors.

For more details, look at the specifications for the Rhomb.io standard.

Power

The Phobos board provides the needed voltages for the Rhomb.io sockets. For doing so, Low Dropout Regulators (LDO) has been included for supplying the "1V8 150mA", "2V8 150mA", "Buck8" and "Buck9" voltages. The "VSYS" voltage is switched in between 5V and Vbat (battery voltage) according to the following cases:

  • There is battery but the USB charger is not connected: VSYS = VBAT
  • There is battery and the USB charger is connected: VSYS = 5V (according to the USB standard)
  • There is no battery and the USB charger is connected: VSYS = 5V (according to the USB standard)
  • There is no battery and the USB charger is not connected: VSYS = 0V

As per the above, the Phobos board can work both connected constantly to a USB 5V source or with a battery. In this last case, only single cell Li-Po or Li-Ion batteries are supported. The charging rate it is fixed to 100mA.


Getting started

In this tutorial the Phobos board will be used in connection with the Duino Uno328P Module and the Sensing MixOne Module. The Duino Uno328P Module will have the master role and the Sensing MixOne Module will be the slave. Altogether will work for showing the data gathered by the five sensors on the Sensing MixOne Module. It is recommended to read the specifications of the two Rhomb.io modules.

It will be done by using the Arduino IDE, so the Duino Uno328P Module will be programmed connecting the Phobos board to a compatible computer trough USB. The Duino Uno328P Module communicates with the Sensing MixOne Module trough I2C and the data is displayed by using the Arduino IDE text console.

Note that the I2C pull-up resistors can be assembled on the Phobos board or on the Duino Uno328P Module. For this tutorial, the resistors are assembled on the Phobos board. Never should be connected on both sides.

Required elements for this tutorial:

  • Rhomb.io Duino Uno328P Module
  • Rhomb.io Sensing MixOne Module
  • Rhomb.io Phobos PCB
  • USB Micro-B cable
  • Arduino IDE installed on a compatible PC

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Follow these steps:
1. Connect the two Rhomb.io modules on the Phobos PCB as it is shown on the gif above. Ensure that the Duino Uno328P Module is connected to the master slot and the Sensing MixOne Module is connected to the slave slot.
2. Connect the USB cable to the Phobos board and to the computer. Ensure that the Arduino IDE is installed. For doing so, it is recommended to read the Arduino IDE Getting Started.
3. Download the sketch on the following link. [Hacer el sketch e incluir el link]
4. Load the "xx" sketch on the Arduino IDE.
5. Some libraries may be needed to install: i2c_t3, etc. [Indicar qué librerias hacen falta. Estas se deberían inlcuir en el .rar ajunto con el sketch]
6. On the Arduino IDE, go to Tools/Board and select "Arduino/Genuino Uno".

Arduino IDE Select Board.jpg

7. Configure the serial port by choosing the proper port on Tools/Port.
8. Upload the code on the Duino Uno328P Module: select "Upload" from the "Sketch" menu or use the shortcut Ctrl+U.

Once the firmware is loaded on the Duino Uno328P Module and if all the steps have been done successfully, the module will read each second from a different sensor. Once all the data is gathered from the five sensors, the data is displayed on the Arduino IDE text console, so each five seconds, a new message will appear on the Serial Monitor such a the following:


Phobos GettingStartedOutput v1.JPG


Schematics

Click the image below to download the schematic files.

Bill of materials

Click the image below to download the BOM files.


Fabrication files

Click the image below to download the fabrication files.


Part number package marking

[Under construction]


Mechanical specifications

Board

Phobos Dimensions v2.png

Connector

[Under construction]


Warranty

  • Precaution against Electrostatic Discharge. When handling Rhomb.io products, ensure that the environment is protected against static electricity. Follow the next recommendations:
  1. The users should wear anti-static clothing and use earth band when manipulating the device.
  2. All objects that come in direct contact with devices should be made of materials that do not produce static electricity that would cause damage.
  3. Equipment and work table must be earthed.
  4. 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.


Disclaimer

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.

All brand names, trademarks and registered trademarks belong to their respective owners.

We are constantly striving to improve the quality of our technical notes. If you find an error or omission please let us know.

Email us at: info@rhomb.io


Where to buy

You can purchase this item at the Rhomb website store.

Please, click the icon below.