AFE-BREAKOUT-MVK MAVRK Module

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Board Status: Level RTM

= Purpose of this Wiki Page =

This page discusses the Modular and Versatile Reference Kit (MAVRK) AFE Breakout module. The AFE-BREAKOUT-MVK provides quick visual inspection of the AFE bus signals via LEDs, as well as a way to easily interface electrically to the AFE bus through headers.

= EVM Overview =

This section contains general information pertinent to this module.

EVM Description
The AFE-BREAKOUT-MVK enables easy debug of the AFE bus by making all the pins available on standard 100mil pin headers for probing or connecting to an external logic analyzer. Furthermore, each GPIO is connected to an LED that turns on when the pin is in a logic high state. A D-type latch holds the state of the GPIOs while the MCU communicates to other AFE modules. The Hardware Design Guide for MAVRK AFE Modules contains more information regarding the GPIO latch.

Highlighted Products
The AFE-BREAKOUT-MVK MAVRK Module features the following devices:


 * TS5A3159 1-Ohm SPDT Analog Switch
 * TPS62120 15V, 75mA, 96% efficiency Step-Down Converter
 * TPS63700 Adjustable, -15V Output Inverting DC/DC Converter in 3x3 QFN
 * SN74LVC1G08 Single 2-Input Positive-AND Gate
 * SN74LVC573A Octal Transparent D-Type Latches With 3-State Outputs
 * TS5A2066 Dual-Channel 10-Ohm SPST Analog Switch

EVM Wiki
AFE-BREAKOUT-MVK MAVRK Module wiki page

EVM Landing Page
AFE-BREAKOUT-MVK MAVRK Module tool folder

= Hardware Description =

Power Requirements
The AFE-BREAKOUT-MVK can be connected to a MAVRK Motherboard through any of the AFE slots. Power (3.3 V and 5.5 V) is supplied by the host board through the AFE connectors. The AFE Breakout board has DC/DC converters that generate +5 V or +/-2.5 V rails. Please note that if you use a companion (adjacent) SCI module that generates power to the AFE slot, you should remove resistors R53 and R60.

Connector Signal Descriptions
For detailed connector pinout information, see the AFE Pinout for MAVRK.

Getting Started: Configuring the EVM
The preferred method of working with this EVM is through a MAVRK Motherboard. The motherboard, along with a MAVRK MCU module, provides the needed power and digital control for this EVM. When used with the MB-PRO-MVK, the AFE-BREAKOUT-MVK can be used in any of the 4 AFE slots to test both the left and right MCU busses. See the Hardware Design Guide for MAVRK AFE Modules for details on AFE-MCU communication.

EVM Jumpers, LEDs, and Test Points
Table 1 lists all the LEDs and headers available on the AFE Breakout board. The headers are connected directly to the AFE bus and care should be taken when probing them. Click here to see a map of the LEDs on the board.

= Software Description =

= Software Project =

Getting Started
A software project named AFE_Breakout_Demo exists in the mavrk_embedded\Modular_EVM_Projects\Component_Demo_Projects\AFE_Breakout_Board_Demo_Project software repository directory. This project contains demo code for using the UART, SPI and I2C buses in the AFE breakout board. MAVRK Boards may be interconnected via the AFE breakout boards using the above mentioned buses.

This demo expects the AFE Breakout board to be in the AFE1 slot as in Figure 12 below.



There are actually three different configurations in the AFE_Breakout_Board_Demo_Project (one for each bus). Using IAR, to select one of the configurations, click on the drop down box in the "workspace" window as shown in the figure below:



Only one configuration can be used at one time. There are three choices:


 * UART_Demo
 * I2C_Demo
 * SPI_Demo

After selecting one of the configurations compile (using "Make") the project and program the board (using "Debug).



UART Demo
Generally for board to board communications, there would be at least two boards. In this case only one is used. The way that send and receive is verified in this project is by connecting the RX and TX lines on the AFE breakout board. What the loopback does is any signal that is transmitted will come back to this device. So when there is a valid receive this proves that the device can transmit and receive successfully. The signals for the UART bus are located on the P3 header on the AFE breakout board. The TX signal is located on header P3 on the 3rd pin. The RX signal is on the same header on the 5th pin. A standard jumper may be used to interconnect these two signals.



Figure 5: Jumper placement for the UART demo

The UART is set by default in the mvk_Init_MAVRK_Standard_Settings function to a baud rate of 460K and 8 bits data, no parity and one stop bit.

Before writing to the UART a handle has to be created and registered using this function call:

This sets the UartDebugHandle to the device which is in AFE1 slot. This handle is later used to communicate with this device.

Then it continually makes this function call   which sends the message out.

The demo continually sends a "Hello from UART". To verify that this transfer is sending and receiving correctly, a breakpoint may be placed on the  function call.



Figure 6: Verifying correct UART transmission with a breakpoint in IAR

This function is called when there is an incoming UART character. The character that has arrived is given in the data parameter. A watch may be placed on this variable and viewed to determine which character has just arrived.

For more information on utilizing the MAVRK UART APIs please refer to MAVRK UART Functions.

SPI Demo
The SPI demo continually sends a message through the SPI bus. As in the case with UART, a loopback is used on the MOSI (output) and MISO (input) pins to test the input portion of the SPI bus.

The signals for the SPI bus are located on the P3 header on the AFE breakout board. The SPI clock is on pin 9, the chip select in on pin 7, MOSI is on pin 11 and MISO in on pin 13.

To set up the loop back of MOSI and MISO jumper pins 11 and 13 as shown in the figure below:



Figure 7: Jumper placement for the SPI demo

To setup the SPI port this function call is used:

Which configures the SPI bus to the AFE1 module device settings.

The project continually sends "Hello from MCU SPI". This sending and receiving may be verified by placing a breakpoint on the SPI call ( . After this line is executed the read variable will hold the results of the input (which should be the message).

The figure below shows the location to place the break point and the watch variable set up:



Figure 8: Verifying correct SPI transmission with a breakpoint in IAR

For more information on utilizing the MAVRK SPI APIs please refer to MAVRK SPI Functions.

I2C Demo
The I2C demo is different from the previous buses demo in that it does not use a loopback. It however writes to an EEPROM chip that is located on the AFE breakout board. This EEPROM (16Kx8) is used to store device information for the breakout board. This information is stored on the highest 256 bytes of the memory. This area should not be overwritten. Any other area is free to be used.

The project writes to the EEPROM chip an 8-bit value and reads that value back to make sure that it was written properly. The bus that is used to do this transfer is I2C.

The actual I2C write call happens deeper in the program but one example is this:

The first parameter is the I2C slave address to write to, the second is the device slot to use for the write (in this case MAVRK_AFE1), then the write data, and the amount of data to write. An example of the I2C read function may be found in the mvk_Read_EEPROM_24xx128 function which may be found in EEPROM24xx128.c.

In the demo, we write 18 bytes of code defined by:

We define the address in the EEProm we want to write to with:

Note: Avoid writing to any address at or above 0x3F00. This are is used at device test to store board description information.

To initiate an I2C write to the EEPROM:

To read back the information on the EEPROM:

The demo writes the data_in to the EEPROM starting at address 0x1000 and reads back the data stored in data_out. The program then verifies that data_in is equal to data_out.

If the verify fails the code will go into an error trap and the RED LED on the MCU will flash.

If the verify passes the code will pass into a  loop and place the MCU in a sleep condition.

To see the resulting data_out, set a watch window and a break point as shown in the figure below:

Figure 9: Verifying correct I2C transmission with a breakpoint in IAR

For more information on using the MAVRK I2C APIs please refer to MAVRK I2C Bus Functions.

Outputing and Inputing on the GPIO
It is only possible to output on the GPIO bus on the AFE breakout board as the bus is behind a register (Note: this is only the case on the AFE breakout board). Also although there are 16 lines on the bus, only the lower half are controllable.

There are two ways to configure this bus and use it. One way is to configure the whole port in one instruction or either break up the configuration to pin by pin.

To configure and set the whole bus in one instruction this function call is used:

To set the port pin by pin this function may be used:

This function call turns off the highest pin (7). The range of pins that may be used are AFE_GPIO_PIN_0...AFE_GPIO_PIN_7.

= Board Files =

Bill of Materials (BOM)
Download PDF of the bill of materials.

 AFE-BREAKOUT-MVK Bill of Materials 

Layout (PDF)
Download a PDF of additional board layers.

 AFE-BREAKOUT-MVK Board Top Silkscreen 

Schematics (PDF)
Download a PDF of the schematic.

 AFE-BREAKOUT-MVK Schematics 

Fabrication Drawings (PDF)
Download a PDF of the fabrication drawing.  AFE-BREAKOUT-MVK Fabrication Drawing 



Request Gerber and Schematic files
To request Gerber or schematic files for the AFE-BREAKOUT-MVK module, please visit the MAVRK Gerber Request webpage.

= Application Note = The I2C and SPI circuits are gated by the MODULE SELECT signal. This means that the breakout will not send through I2C or SPI signals unless the MODULE SELECT line is active. Standard MAVRK software functions that perform I2C and SPI read/writes manage the MODULE SELECT line for the user.

If the user is using the breakout module to monitor I2C or SPI bus activity, the system will need to enable the MODULE SELECT line for the device slot that contains the breakout card. In the software, this is done via the mvk_Set_Module_Select function.

= Important Notices =

Certifications
FCC standard EMC test report for the MAVRK STK-PRO430-MVK Starter Kit, featuring the AFE-BREAKOUT-MVK Module

ICES standard EMC test report for the MAVRK STK-PRO430-MVK Starter Kit, featuring the AFE-BREAKOUT-MVK Module

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