WICED Bluetooth Using the CYW20719

Source code: 

• git@github.com:iotexpert/wiced_bt_intro.git
• https://github.com/iotexpert/wiced_bt_intro

 

Summary

In this lesson we are going to build the simplest project that I could think of… turning an LED on/off with Bluetooth Low Energy.

The important BLE concepts are

1. What is a Central / Peripheral
2. What is Advertising
3. What is a GATT Database

The important WICED Bluetooth Concepts are:

1. How do you run WICED Bluetooth Designer
2. What is the structure of a WICED Bluetooth Project
3. What is a Callback
4. How is the GATT Database Implemented
5. How to run CySmart

The steps that we will follow are:

1. Run BT Designer
2. Create a project called L5_BluetoothLED
3. Go to the characteristics page
4. Add a vendor specific service
5. Name the Service L5Service
6. Add an optional characteristic that is vendor specific
7. Name it RED
8. Make it 1 byte with an initial value of 01
9. Set it up for host write
10. Add a user description to the characteristic
11. Generate the code
12. Move the folder to the wiced_bt_class folder
13. Fix the three include problems
14. Reset the debug UART to PUART
15. When there is a write, change the value of the WICED_LED_1 GPIO
16. Test

BLE Concepts

In the world of BLE there are two sides of every connection

• The Central – typically a cellphone
• The Peripheral – your WICED device

Centrals listen for Peripherals that are Advertising.  Advertising is a periodic packet of up to 31 bytes of information that a Peripheral will send out to make it presence known.  When a Central hears the Advertising packets of a Peripheral that is “interesting” it can initiate a connection.

Once a connection is made, how do you exchange information?  The answer is that a Peripheral has a database running inside of it.  The database is called a “GATT database”.   A Central can perform “Service Discovery” to find all of the legal stuff in the database.  The GATT database is organized into one or more “Services” that have one or more “Characteristics”.  For instance a Heart Rate Monitor might have a “Heart Rate Service” with two characteristics, one for heart rate and one for battery level.

There are two types of Services.  Ones that are specified by the Bluetooth SIG, like heartrate.  And vendor specific custom services.

Run Bluetooth Designer

The Bluetooth Designer is a GUI tool that we built into Eclipse.  It allows you to configure some of the fundamental Bluetooth feature (like the GATT Database) and then automatically generate the code.  Start Bluetooth Designer by running File->New->WICED Bluetooth Designer.

Since this is Lesson 5 and we are going to write and LED… call the project “L5_BluetoothLED”

Once you start BT Designer, you screen should look like this.  The project is going to be a BLE only project.

The Characteristics button lets you setup the GATT database.

Add a service by selecting vendor specific service and then hitting the “+”

I’ll call the service “L5Service”

Next add a characteristic by selecting “vendor specific characteristic” and pressing “+”

Change the name to “RED”, Make the device role “Host write to or reads from service”.  Make the size 1 byte and set the initial value to 01 (it must be 01 not 1 or 001)

When we are looking at this remotely you would like to be able to see the user description.  So click that tab and give it a description.

Press Generate Code button.  You will end up with a folder in the top level apps directory.  I don’t like this, so lets move it into our class projects folder.  You can do this by dragging the folder to the wiced_bt_class folder.  Now it should look like this:

Unfortunately, there are three little issues that this creates which need to be fixed.  First, you need to fix L5_BluetoothLED.c as this include is wrong.

#include "../wiced_bt_class/L5_BluetoothLED/L5_BluetoothLED_db.h"

And change it to:

#include "L5_BluetoothLED_db.h"

Next edit L5_BluetoothLED_db.h and add the #include “wiced.h”

#include "wiced.h"

Finally edit the L5_BluetoothLED_db.c to fix the same include problem.

#include "../wiced_bt_class/L5_BluetoothLED/L5_BluetoothLED_db.h"

It should be like this.

#include "L5_BluetoothLED_db.h"

Now edit the make target that was created by the BT Designer and change it to:

Remember in the earlier lesson I showed you about the WICED HCI UART and the WICED PUART.  Well by default the WICED_BT_TRACE is setup to go to the HCI UART.  So, lets fix the output of BT_TRACE to go to the PUART by changing the file “L5_BluetoothLED.c”

#if ((defined WICED_BT_TRACE_ENABLE) || (defined HCI_TRACE_OVER_TRANSPORT))
    /* Set the Debug UART as WICED_ROUTE_DEBUG_NONE to get rid of prints */
    //  wiced_set_debug_uart( WICED_ROUTE_DEBUG_NONE );

    /* Set Debug UART as WICED_ROUTE_DEBUG_TO_PUART to see debug traces on Peripheral UART (PUART) */
      wiced_set_debug_uart( WICED_ROUTE_DEBUG_TO_PUART );

    /* Set the Debug UART as WICED_ROUTE_DEBUG_TO_WICED_UART to send debug strings over the WICED debug interface */
    //wiced_set_debug_uart( WICED_ROUTE_DEBUG_TO_WICED_UART );
#endif

The last thing that we want to do is fix it so that when the Central writes a new value into the RED LED characteristic we should write the GPIO to the new value.  In L5_BluetoothLED.c make this change.

     case HDLC_L5SERVICE_RED_VALUE:
                       WICED_BT_TRACE("LED = %d\n",l5_bluetoothled_l5service_red[0]);
                       wiced_hal_gpio_set_pin_output(WICED_GPIO_PIN_LED_2,l5_bluetoothled_l5service_red[0]);
                       break;

Now build the project and see what happens.  The first testing step will be to open CySmart.  You can see that a device called “L5_BluetoothLED” is advertising.

When I click it, you can see that there is a GattDB.

When I click on the database, I can see that there is only one service (which makes sense as we setup only one)

Click on the Service and you can see that there is only one characteristic in the service… and its value is 01.

When you click the descriptor button you can see that there is a Characteristic User Description

 

And finally the value is “Red LED Value”.  That is what we setup.

When you click back … then click on the write it will bring up this window where I can send a new value.

Now the value is 0x00 and the RED LED is on (remember from earlier that it is active low so that makes sense)

 

And when I look at the terminal I can see two writes (I wrote again before I took this screen shot)

A Tour of the Source Code

The GATT Database is in the file L5_BluetoothLED_db.c

const uint8_t gatt_database[] = // Define GATT database
{
    /* Primary Service 'Generic Attribute' */
    PRIMARY_SERVICE_UUID16 (HDLS_GENERIC_ATTRIBUTE, UUID_SERVICE_GATT),

    /* Primary Service 'Generic Access' */
    PRIMARY_SERVICE_UUID16 (HDLS_GENERIC_ACCESS, UUID_SERVICE_GAP),

        /* Characteristic 'Device Name' */
        CHARACTERISTIC_UUID16 (HDLC_GENERIC_ACCESS_DEVICE_NAME, HDLC_GENERIC_ACCESS_DEVICE_NAME_VALUE,
            UUID_CHARACTERISTIC_DEVICE_NAME, LEGATTDB_CHAR_PROP_READ,
            LEGATTDB_PERM_READABLE),

        /* Characteristic 'Appearance' */
        CHARACTERISTIC_UUID16 (HDLC_GENERIC_ACCESS_APPEARANCE, HDLC_GENERIC_ACCESS_APPEARANCE_VALUE,
            UUID_CHARACTERISTIC_APPEARANCE, LEGATTDB_CHAR_PROP_READ,
            LEGATTDB_PERM_READABLE),

    /* Primary Service 'L5Service' */
    PRIMARY_SERVICE_UUID128 (HDLS_L5SERVICE, __UUID_L5SERVICE),

        /* Characteristic 'RED' */
        CHARACTERISTIC_UUID128_WRITABLE (HDLC_L5SERVICE_RED, HDLC_L5SERVICE_RED_VALUE,
            __UUID_L5SERVICE_RED, LEGATTDB_CHAR_PROP_READ | LEGATTDB_CHAR_PROP_WRITE,
            LEGATTDB_PERM_READABLE | LEGATTDB_PERM_WRITE_REQ),

            /* Descriptor 'Characteristic User Description' */
            CHAR_DESCRIPTOR_UUID16 (HDLD_L5SERVICE_RED_USER_DESCRIPTION,
                UUID_DESCRIPTOR_CHARACTERISTIC_USER_DESCRIPTION, LEGATTDB_PERM_READABLE),

};

Each row in the Database table has a unique “Handle” that is defined in the L5_BluetoothLED_db.h

#define __UUID_L5SERVICE                      0x30, 0x9d, 0x7f, 0x29, 0x73, 0xca, 0x4f, 0xfd, 0xa5, 0x68, 0x17, 0xd8, 0x90, 0x67, 0x7f, 0x35
#define __UUID_L5SERVICE_RED                  0x29, 0xbf, 0x86, 0xa6, 0xc8, 0x6c, 0x4e, 0xa5, 0xaa, 0x56, 0xbd, 0xac, 0x72, 0x80, 0x93, 0xa9

// ***** Primary Service 'Generic Attribute'
#define HDLS_GENERIC_ATTRIBUTE                0x0001

// ***** Primary Service 'Generic Access'
#define HDLS_GENERIC_ACCESS                   0x0014
// ----- Characteristic 'Device Name'
#define HDLC_GENERIC_ACCESS_DEVICE_NAME       0x0015
#define HDLC_GENERIC_ACCESS_DEVICE_NAME_VALUE 0x0016
// ----- Characteristic 'Appearance'
#define HDLC_GENERIC_ACCESS_APPEARANCE        0x0017
#define HDLC_GENERIC_ACCESS_APPEARANCE_VALUE  0x0018

// ***** Primary Service 'L5Service'
#define HDLS_L5SERVICE                        0x0028
// ----- Characteristic 'RED'
#define HDLC_L5SERVICE_RED                    0x0029
#define HDLC_L5SERVICE_RED_VALUE              0x002A
// ===== Descriptor 'User Description'
#define HDLD_L5SERVICE_RED_USER_DESCRIPTION   0x002B

Each characteristic value is held in one of the uint8_t arrays found in “L5_BluetoothLED.c”

/*******************************************************************
 * GATT Initial Value Arrays
 ******************************************************************/
uint8_t l5_bluetoothled_generic_access_device_name[]     = {'L','5','_','B','l','u','e','t','o','o','t','h','L','E','D'};
uint8_t l5_bluetoothled_generic_access_appearance[]      = {0x00,0x00};
uint8_t l5_bluetoothled_l5service_red[]                  = {0x01};
uint8_t l5_bluetoothled_l5service_red_user_description[] = {'R','E','D',' ','L','e','d',' ','V','a','l','u','e'};

/*******************************************************************
 * GATT Lookup Table
 ******************************************************************/

/* GATT attribute lookup table                                */
/* (attributes externally referenced by GATT server database) */
gatt_db_lookup_table l5_bluetoothled_gatt_db_ext_attr_tbl[] =
{
    /* { attribute handle,                  maxlen,                                                 curlen,                                                 attribute data } */
    {HDLC_GENERIC_ACCESS_DEVICE_NAME_VALUE, 15,                                                     15,                                                     l5_bluetoothled_generic_access_device_name},
    {HDLC_GENERIC_ACCESS_APPEARANCE_VALUE,  2,                                                      2,                                                      l5_bluetoothled_generic_access_appearance},
    {HDLC_L5SERVICE_RED_VALUE,              1,                                                      1,                                                      l5_bluetoothled_l5service_red},
    {HDLD_L5SERVICE_RED_USER_DESCRIPTION,   sizeof(l5_bluetoothled_l5service_red_user_description), sizeof(l5_bluetoothled_l5service_red_user_description), l5_bluetoothled_l5service_red_user_description},
};

 

 

WICED Bluetooth Using the CYW20719

Source code: 

• git@github.com:iotexpert/wiced_bt_intro.git
• https://github.com/iotexpert/wiced_bt_intro

 

Summary

In this lesson I am going to show you how to NOT write all of your own code and still get the job done.  In this lesson we are going to do three things.

1. Examine & Run the hal_gpio snip
2. Examine & Run the hal_i2c_master snip
3. Copy the hal_i2c_master snip and make it “more better”

To modify the hal_i2c_master snip I will

1. Make a new folder called L4_Accelerometer
2. Copy the makefile.mk and hal_i2c_master.c into the L4_Accelerometer folder
3. Create a new make target and make sure that things still work
4. Look at the LSM9DS1 datasheet
5. Update the function initialize_app to startup the Accelerometer and speed up the polling
6. Update the function comboread_cb to read the Acceleration registers and print out the values

Run hal_gpio

If you dont already have a make target for snip.hal.hal_gpio create one and then program the board.

Notice that the light blinking will change speeds if you press the button.  Let’s look at the code that does this:

At the beginning it sets up a timer

        // Initialize timer to control the pin toggle frequency
        if (wiced_init_timer(&hal_gpio_app_timer, &hal_gpio_app_timer_cb, 0, WICED_SECONDS_PERIODIC_TIMER) == WICED_SUCCESS)
        {
            if (wiced_start_timer(&hal_gpio_app_timer, LED_BLINK_FREQ_A_IN_SECONDS) != WICED_SUCCESS)
            {
                WICED_BT_TRACE("Seconds Timer Error\n");
            }
        }

The timer calls this function each time the timer expires.

/*
 * The function invoked on timeout of app. seconds timer.
 */
void hal_gpio_app_timer_cb(uint32_t arg)
{
    static uint32_t wiced_seconds = 0; /* number of seconds elapsed */
    uint8_t index = 0;

    wiced_seconds++;

    if (wiced_seconds & 1)
    {
        for (index = 0; index < sizeof(output_pin_list); index++)
        {
            wiced_hal_gpio_set_pin_output(output_pin_list[index], GPIO_PIN_OUTPUT_LOW);
        }
    }
    else
    {
        for (index = 0; index < sizeof(output_pin_list); index++)
        {
            wiced_hal_gpio_set_pin_output(output_pin_list[index], GPIO_PIN_OUTPUT_HIGH);
        }
    }
}

And when the button is pressed all it does is switch back and forth between two different intervals for the timer.  And after the switch it restarts the timer.

/*
 * Handle interrupt generated due to change in the GPIO state
 */
void hal_gpio_app_interrrupt_handler(void *data, uint8_t pin)
{
    static uint32_t blink_freq = LED_BLINK_FREQ_A_IN_SECONDS;

    // toggle LED blink rate upon each button press
    if (blink_freq == LED_BLINK_FREQ_A_IN_SECONDS)
    {
        blink_freq = LED_BLINK_FREQ_B_IN_SECONDS;
    }
    else
    {
        blink_freq = LED_BLINK_FREQ_A_IN_SECONDS;
    }

    if (wiced_stop_timer(&hal_gpio_app_timer) == WICED_SUCCESS)
    {
        wiced_start_timer(&hal_gpio_app_timer, blink_freq);
    }

    // clear the interrupt status
    wiced_hal_gpio_clear_pin_interrupt_status(pin);
}

Run hal_i2c_master

This CYW920719Q40EVB_01 development kit has an I2C LSM9DS1 accelerometer on it.  And I noticed that when looking around in the snips that the Snip called “hal_i2c_master.c” appears to talk to the chip.  Here is a little section of the comments from the top of the snip

 *
 * WICED sample application for I2C Master usage
 *
 * This application demonstrates how to use I2C driver interface
 * to send and receive bytes or a stream of bytes over the I2C hardware as a master.
 * The on-board LSM9DS1 motion sensor acts as the I2C slave

So, lets run the snip and see what happens.  If you don’t have a make target… well then make one.

Then make the make target.

It turns out that “0” is a bug in the example project.  And printing out the WHO_AM_I register isnt really very interesting.

Modify the hal_i2c_master.c Create a Better Project

I don’t like making changes inside of the WICED SDK files.  But, I want to fix the bug and printout something more interesting.  So start by creating a new folder in the wiced_bt_class folder

Type in the directory name L4_Accelerometer (notice in the screenshot below I mistyped it)

Select the makefile.mk and the hal_i2c_master.c then right click copy the files.

Then select the L4_Accelerometer folder and pick paste.

Create a make target for the L4_Accelerometer

Build it to make sure it still works.

Now that we have a base to stand-on.  Let’s have a look at the data sheet.  I have used these before and I know that you need to turn on the Accelerometer to give you anything interesting.  Turns out CTRL_REG_6_XL is the control register we need.

The other interesting registers are the actual output of the accelerometer.  That is 0x28 –> 0x2D

Start by modifying the function initialize_app to turn on the accelerometer by writing 0x40 to register 0x20

uint8_t status;
    // Turn on Accelerometer - Register 0x20... 2g accelerometer on @ 50hz
    uint8_t data[] = {0x20, 0x40};
    status = wiced_hal_i2c_write(data,sizeof(data),LSM9DS1_ACC_GYRO_I2C_ADDRESS);

I dont really like printing the values every two seconds so I will modify the timer:

• Make it a milisecond timer
• Set it to print every 500ms

if ( WICED_SUCCESS == wiced_init_timer( &seconds_timer, &comboread_cb, 0, WICED_MILLI_SECONDS_PERIODIC_TIMER )) {
        if ( WICED_SUCCESS != wiced_start_timer( &seconds_timer, 500 )) {
            WICED_BT_TRACE( "Seconds Timer Error\n\r" );
        }
    }

Here is the whole function initialize_app together

void initialize_app( void )
{
    wiced_hal_i2c_init();
    uint8_t status;

    // Turn on Accelerometer - Register 0x20... 2g accelerometer on @ 50hz
    uint8_t data[] = {0x20, 0x40};
    status = wiced_hal_i2c_write(data,sizeof(data),LSM9DS1_ACC_GYRO_I2C_ADDRESS);


    /* register callback for button available on the platform */
    wiced_platform_register_button_callback( WICED_PLATFORM_BUTTON_1, button_cb, NULL, WICED_PLATFORM_BUTTON_RISING_EDGE);

    current_speed = wiced_hal_i2c_get_speed();

    WICED_BT_TRACE("Default I2C speed: %d KHz\n", (CLK_FREQ/current_speed));

    /*Start a timer for POLL_TIMER seconds*/

    if ( WICED_SUCCESS == wiced_init_timer( &seconds_timer, &comboread_cb, 0, WICED_MILLI_SECONDS_PERIODIC_TIMER )) {
        if ( WICED_SUCCESS != wiced_start_timer( &seconds_timer, 500 )) {
            WICED_BT_TRACE( "Seconds Timer Error\n\r" );
        }
    }

}

Next I need to modify the comboread_cb callback.  It will

• Setup a structure to hold the three acceleration values (Line 145)
• Then it will read from the LSM9DS1 (Line 152)
• Then print them (Line 156)

/******************************************************************************
 * This function reads the value from I2C slave and prints it
 *****************************************************************************/

void comboread_cb (uint32_t arg)
{
    UINT8  status = 0xFF;
    UINT8 reg_add = 0x28; // Acceleromter register

    typedef struct {
        int16_t ax;
        int16_t ay;
        int16_t az;
    } __attribute__((packed)) accel_val_t;

    accel_val_t data;
    status = wiced_hal_i2c_combined_read((UINT8 *)&reg_add, sizeof(UINT8), (uint8_t *)&data, sizeof(data), LSM9DS1_ACC_GYRO_I2C_ADDRESS);

    if(I2CM_SUCCESS == status) {

        WICED_BT_TRACE("Ax=%d Ay=%d Az=%d\n",data.ax,data.ay,data.az);
    }else if(I2CM_OP_FAILED == status) {
        WICED_BT_TRACE("I2C comboread operation failed\r\n");
    }else if(I2CM_BUSY == status) {
        WICED_BT_TRACE("I2C busy\r\n");
    }else{
        WICED_BT_TRACE("Unknown status from I2C\r\n");
    }

}

Now double click the make target and make sure that everything is working.

WICED Bluetooth Using the CYW20719

Source code: 

• git@github.com:iotexpert/wiced_bt_intro.git
• https://github.com/iotexpert/wiced_bt_intro

 

Summary

You probably noticed and wondered “Why did he use WICED_LED_2 instead of WICED_LED_1”?  The answer to that question is that by default the CYW920719Q40EVB_01 is setup with WICED_LED_2 enabled as a GPIO and WICED_LED_1 used for another purpose.  But to what purpose?  In this lesson we will answer the questions:

1. What are the default pins?
2. How do you use the SuperMux tool?
3. How do you use a PWM?

To do this we are going to copy the L2_HelloWorld project and add a PWM to drive the Green LED also known as WICED_LED_1.

The steps we are going to follow are

1. Copy the L2_HelloWorld to start a new project called L3_SuperMux
2. Rename L2_HelloWorld.c
3. Fix the makefile.mk for the updated source file
4. Create a new make target
5. Program to make sure everything is still working
6. Look at the platform files for CYW920719Q40EVB_01
7. Run  the SuperMux Tool
8. Delete the SPI Slave_1 From the SuperMux
9. Add an LED to the SuperMux
10. Configure the LED to P28
11. Apply the SuperMux configuration
12. Look at the new files added to the project
13. Look a the makefile.mk
14. Look L3_SuperMux_pin_config.c
15. Update L3_SuperMux.c to have correct includes
16. Update L3_SuperMux.c to start the clock, pin and PWM
17. Program the project
18. Look at the Hardware Abstraction Layer Documentation

Copy L2_HelloWorld –> L3_SuperMux

Instead of starting from a blank project.  Lets make a copy of the L2_HelloWorld project.  If you right click on the L2_HelloWorld folder and select copy

Then click on the “wiced_bt_class” folder and select paste.

WICED Studio will then complain that you already have a directory called “L2_HelloWord” and give you the opportunity to rename it.  Call the new project “L3_SuperMux”

Now you need to rename the L2_HelloWorld.c to be L3_SuperMux.c.  Right click on the L2_HelloWorld.c and select rename

Then give it a new file name… like L3_SuperMux.c

Double click makefile.mk and edit it.  You need to change the comment, and the name of the APP_SRC source file.

#
# Lesson 3 - SuperMux
#
APP_SRC +=  L3_SuperMux.c

C_FLAGS += -DWICED_BT_TRACE_ENABLE

Create a make target for this project by right clicking the L2_HelloWorld Make Target, then selecting “New”

That will make a new target… and it will bring up this dialog box.  Notice that it named the target “Copy of …”

Fix it to be “L3_SuperMux” like this:

You should now have an exact copy of L2_HelloWorld, in the project L3_SuperMux.  Double click the make target and make sure that things are still working.  When you build you should get this.  Don’t forget to “Start the Bootloader” if the programming doesn’t work.

Platform Files

If you look on the back of your CYW920719Q40EVB-01 development kit you will find the exact pin map of this board.  On this picture you can see that LED1 is connected to P28

In WICED Studio, the world “Platform” is just another word for Board Support Package.  Basically all of the configuration required to build the firmware for a specific board.  If you click on platforms you will find a directory for the CYW920719Q40EVB.  All of the default configuration for the pins are located in the file “wiced_platform_pin_config.c”

If you look at this file closely, you will see on line 47 that pin P28 is setup as the MOSI of WICED_SPI_1.  That isnt a GPIO!!!.  And you will see a whole block of code on line 74 that is commented out that COULD   configure P28 as a GPIO.  But that would require modifying our default platform files, which I dont want to do.  Now what?  Simple use the SuperMux tool.

/* all the pins available on this platform and their chosen functionality */
const wiced_platform_gpio_t platform_gpio_pins[] =
    {
        [PLATFORM_GPIO_0 ] = {WICED_P00, WICED_GPIO              },      //Button
        [PLATFORM_GPIO_1 ] = {WICED_P01, WICED_SPI_1_MISO        },
        [PLATFORM_GPIO_2 ] = {WICED_P02, WICED_PCM_OUT_I2S_DO    },
        [PLATFORM_GPIO_3 ] = {WICED_P04, WICED_PCM_IN_I2S_DI     },
        [PLATFORM_GPIO_4 ] = {WICED_P06, WICED_GCI_SECI_IN       },
        [PLATFORM_GPIO_5 ] = {WICED_P07, WICED_SPI_1_CS          },
        [PLATFORM_GPIO_6 ] = {WICED_P10, WICED_GCI_SECI_OUT      },
        [PLATFORM_GPIO_7 ] = {WICED_P16, WICED_PCM_CLK_I2S_CLK   },
        [PLATFORM_GPIO_8 ] = {WICED_P17, WICED_PCM_SYNC_I2S_WS   },
        [PLATFORM_GPIO_9 ] = {WICED_P26, WICED_GPIO              },      //Default LED 2
        [PLATFORM_GPIO_10] = {WICED_P25, WICED_I2C_1_SCL         },
        [PLATFORM_GPIO_11] = {WICED_P28, WICED_SPI_1_MOSI        },      //Optional LED 1
        [PLATFORM_GPIO_12] = {WICED_P29, WICED_I2C_1_SDA         },
        [PLATFORM_GPIO_13] = {WICED_P33, WICED_UART_2_TXD        },
        [PLATFORM_GPIO_14] = {WICED_P34, WICED_UART_2_RXD        },
        [PLATFORM_GPIO_15] = {WICED_P38, WICED_SPI_1_CLK         },
    };

/* LED configuration */
const wiced_platform_led_config_t platform_led[] =
    {
        [WICED_PLATFORM_LED_2] =
            {
                .gpio          = (wiced_bt_gpio_numbers_t*)&platform_gpio_pins[PLATFORM_GPIO_9].gpio_pin,
                .config        = ( GPIO_OUTPUT_ENABLE | GPIO_PULL_UP ),
                .default_state = GPIO_PIN_OUTPUT_HIGH,
            },

// We can use either LED1 or SPI1 MOSI, by default we are using WICED_P28 for SPI1 MOSI,
// uncomment the following initialization if WICED_P28 is to be used as an LED and set PIN
// functionality in platform_gpio_pins as WICED_GPIO

//        [WICED_PLATFORM_LED_1] =
//            {
//                .gpio          = (wiced_bt_gpio_numbers_t*)&platform_gpio_pins[PLATFORM_GPIO_11].gpio_pin,
//                .config        = ( GPIO_OUTPUT_ENABLE | GPIO_PULL_UP ),
//                .default_state = GPIO_PIN_OUTPUT_HIGH,
//            }
    };

SuperMux Tool

The SuperMux tool is a GUI for setting the default configurations of the Pins on the chip.  Like all capable MCUs, this chip has PWMs, SPIs, UARTs, GPIOs, I2C, ADCs etc.  Each pin on the chip can do a bunch of different functions, but only one at a time.  Each pin has a multiplexor in front of it that selects the function of that pin.  The SuperMux tool helps you setup the multiplexors for each pin on the chip.

To run the SuperMux tool, first click on your project directory (remember L3_SuperMux).  The select File–>New–>WICED SuperMux GPIO Pin Configuration

It will ask you which “App Name” you want it to work on.  Since we clicked on the L3_SuperMux app, it uses that name by default.  Press Next

The SuperMux Wizard will give you the opportunity to select which pins you want to configure.  It also shows you the default configuration of each of the pins.  In this case just press “Next” because we want to configure them all.

Now you will see the functions of the chip and which pins they are assigned to.  Notice that WICED_P28 is assigned as the MOSI of SPI(Slave)_1.  We don’t want that.

Remove the SPI(Slave)_1 by selecting it and then pressing the “Remove” button

Now your screen will look like this.  In order to add a new pin configuration you can press the little “+” at the bottom of the function column.

Next press the little “+” button and select LED.

The select which Pin you want assigned to the LED.  In this case we want WICED_P28

After you press finish you will notice that it adds a several files to your project.  And you notice that it creates a file called “makefile.mk.bak” (which is the backup of the original makefile)

First look at the makefile and notice that it added the “L3_SuperMux_pin_config.c” to the sources and added a CFLAG

#
# Lesson 3 - SuperMux
#
APP_SRC +=  L3_SuperMux.c

C_FLAGS += -DWICED_BT_TRACE_ENABLE
C_FLAGS += -DSMUX_CHIP=$(CHIP)
APP_SRC += L3_SuperMux_pin_config.c

So, what is up with the  L3_SuperMux_pin_config.c.  OH!!! I See, this is just a replacement for the default platform configuration.  Notice that P28 is now a WICED_GPIO and that it is now defined in the LED list.

wiced_platform_gpio_t platform_gpio_pins[]=
	{
		[PLATFORM_GPIO_0]	= {WICED_P00, WICED_GPIO},
		[PLATFORM_GPIO_1]	= {WICED_P02, WICED_PCM_OUT_I2S_DO},
		[PLATFORM_GPIO_2]	= {WICED_P04, WICED_PCM_IN_I2S_DI},
		[PLATFORM_GPIO_3]	= {WICED_P06, WICED_GCI_SECI_IN},
		[PLATFORM_GPIO_4]	= {WICED_P10, WICED_GCI_SECI_OUT},
		[PLATFORM_GPIO_5]	= {WICED_P16, WICED_PCM_CLK_I2S_CLK},
		[PLATFORM_GPIO_6]	= {WICED_P17, WICED_PCM_SYNC_I2S_WS},
		[PLATFORM_GPIO_7]	= {WICED_P25, WICED_I2C_1_SCL},
		[PLATFORM_GPIO_8]	= {WICED_P26, WICED_GPIO},
		[PLATFORM_GPIO_9]	= {WICED_P28, WICED_GPIO},
		[PLATFORM_GPIO_10]	= {WICED_P29, WICED_I2C_1_SDA},
		[PLATFORM_GPIO_11]	= {WICED_P33, WICED_UART_2_TXD},
		[PLATFORM_GPIO_12]	= {WICED_P34, WICED_UART_2_RXD},
	};

const wiced_platform_button_config_t platform_button[WICED_PLATFORM_BUTTON_MAX]=
	{
		[WICED_PLATFORM_BUTTON_1] =
			{
				.gpio			= &platform_gpio_pins[PLATFORM_GPIO_0].gpio_pin,
				.config			= (GPIO_INPUT_ENABLE | GPIO_PULL_UP),
				.default_state	= GPIO_PIN_OUTPUT_LOW,
				.button_pressed_value	= GPIO_PIN_OUTPUT_LOW,
			},
	};

const size_t button_count =  (sizeof(platform_button) / sizeof(wiced_platform_button_config_t));


const wiced_platform_led_config_t platform_led[WICED_PLATFORM_LED_MAX]=
	{
		[WICED_PLATFORM_LED_1] =
			{
				.gpio			= &platform_gpio_pins[PLATFORM_GPIO_9].gpio_pin,
				.config			= (GPIO_OUTPUT_ENABLE | GPIO_PULL_UP),
				.default_state	= GPIO_PIN_OUTPUT_HIGH,
			},
		[WICED_PLATFORM_LED_2] =
			{
				.gpio			= &platform_gpio_pins[PLATFORM_GPIO_8].gpio_pin,
				.config			= (GPIO_OUTPUT_ENABLE | GPIO_PULL_UP),
				.default_state	= GPIO_PIN_OUTPUT_HIGH,
			},
	};

Now that the pins are configured.  We need to setup the PWM.

Configure the Clock and the PWM

Now I will add a little bit of code to the top of  our L3_SuperMux.c to configure the PWM, Clock and Pin.

First add includes for the ACLK and PWM driver.

#include "wiced_hal_aclk.h"
#include "wiced_hal_pwm.h"

Then startup the Clock, Pin and PWM.

    wiced_hal_aclk_enable(2000, ACLK1, ACLK_FREQ_1_MHZ );
    wiced_hal_pwm_configure_pin (WICED_GPIO_PIN_LED_1, PWM1 );
    wiced_hal_pwm_start(PWM1, PMU_CLK, 0xFFFF-500, 0xFFFF-999,0);

If you want to turn on the PWM you need to do three things

1. Turn on a clock to drive it (line 17) sets the clock frequency to 2000hz
2. Attach the PWM to a Pin (line 18) attaches PWM 1 to the pin
3. Turn on the PWM which is a 16-bit up-counting PWM.  When the PWM is reset it will go to 0xFFFF-999 (the period)… then it will switch at 0xFFFF-500 (the compare value)

When you program this your Green LED aka WICED_LED_1 is being driven by the PWM.  And your RED LED is being driven by your firmware.

Documentation

All of the hardware blocks on the chip have a set of API functions to help you interface with them.  You can find all of that in the Documentation

WICED Bluetooth Using the CYW20719

Source code: 

• git@github.com:iotexpert/wiced_bt_intro.git
• https://github.com/iotexpert/wiced_bt_intro

 

Summary

For our first project, I am going to stand on the shoulder of giants.  In 1978, Brian Kernighan and Dennis Ritchie published “The C Programming Language”.  Here are pictures of my copy.

The reason you do “Hello, World” is that you want to make sure that your compiler chain, programmer etc are all working correctly with something that is super simple.  The only change that I will make to their classic program is to add the “Blinking LED” which is the embedded developers version of “Hello, World”.

The concepts that I want to show in this lesson are.

1. How to make a new project – makefile.mk, <appname>.c
2. How NOT to make a new project
3. How to create a “Make Target”
4. CYW920719Q40EVB01 Development Kit
5. WICED PUART and WICED HCI UART
6. How to start the bootloader
7. Where the documentation resides for the WICED 20719 hardware abstraction layer
8. WICED uses ThreadX RTOS

To make this first project the steps are:

1. Make a new folder called wiced_bt_class  in the Apps Folder
2. Make a new folder called L2_HelloWorld in the wiced_bt_intro Folder
3. Create a new file called L2_HelloWorld.c
4. Create a new file called makefile.mk
5. Add the code to print HelloWorld & blink the LED to L2_HelloWorld.c
6. Add the secret incantation to makefile.mk to build the project
7. Create a “Make Target”
8. Connect the development kit to your computer
9. Attach a serial terminal to the PUART
10. Run the Make Target to Build and Program

Lets do this!

DO NOT DO File->New Project

I always hate to start with a negative statement… but DO NOT make a file project by doing File->New Project.  This is used for creating a new Eclipse project, not a new WICED Studio project.  In WICED Studio we use the make external build system.  If you do File->New Project all hell is going to break loose.  So don’t do any of the things on this menu:

Hello World & Blinking LED

Now lets get on with making a WICED Studio Project.  First create a new folder to hold the projects for the Class in the “Apps” folder by right-clicking and selecting New->Folder

Give it the name “wiced_bt_class”

Create a folder to hold the first project called L2_HelloWorld

Call the folder L2_HelloWorld

Make a new file called L2_HelloWorld.c by right clicking on the L2_HelloWorld folder and selecting New–>File

Give it the name L2_HelloWorld.c

Make a new file called makefile.mk by right clicking on the L2_HelloWorld directory and selecting New->File

and giving it the name makefile.mk

Add some code to the L2_HelloWorld.c

#include "wiced.h"
#include "sparcommon.h"
#include "wiced_platform.h"
#include "wiced_rtos.h"
#include "wiced_hal_gpio.h"
#include "wiced_bt_trace.h"

APPLICATION_START()
{
    wiced_set_debug_uart(WICED_ROUTE_DEBUG_TO_PUART);

    WICED_BT_TRACE("Hello, World\n");
    while(1)
    {

        WICED_BT_TRACE("Setting 0\n");
        wiced_hal_gpio_set_pin_output(WICED_GPIO_PIN_LED_2,0);
        wiced_rtos_delay_milliseconds(500,KEEP_THREAD_ACTIVE );
        WICED_BT_TRACE("Setting 1\n");
        wiced_hal_gpio_set_pin_output(WICED_GPIO_PIN_LED_2,1);
        wiced_rtos_delay_milliseconds(500,KEEP_THREAD_ACTIVE );
    }
}

Add the secret incantation to the makefile.mk

#
# Lesson 2 - Hello, World
#
APP_SRC +=  L2_HelloWorld.c

C_FLAGS += -DWICED_BT_TRACE_ENABLE

Create a make target

The make target has a VERY specific format.  It is:

directory.directory.appname-platform download

In our case we have all of our projects in a directory called “wiced_bt_class”.  Then we have a directory called “L2_HelloWorld” which holds the exact project.  And our platform name is “CYW920719Q40EVB_01”

Connect the Development Kit To Your Computer

When you plug in your development kit, it will USB enumerate a TWO serial ports.  One of the serial ports (the first one) is called the “WICED HCI UART”.  The second serial port is called the “WICED Peripheral UART” (this is often abbreviated “PUART”)

One of the key things that the WICED HCI UART is used as is a UART to download new code to the bootloader.

The PUART is used as a general purpose serial port.  When we call this function it causes all of our “WICED_BT_TRACE” outputs to go to the the PUART.

    wiced_set_debug_uart(WICED_ROUTE_DEBUG_TO_PUART);

You can see these two UARTs on a PC by running the device manager.

You can see COM17 is the “WICED HCI UART” and COM18 is the “WICED Peripheral UART”

On my Mac I use the program “Serial” which I downloaded from the App Store.

When I run Serial and then to open a Port

You can see the two UARTs.

In order to see the output I will connect to the port with the settings

• 115200 Baud
• 8-n-1 (Data bits, Parity, Stop Bits)

With my PC I typically use Putty (remember it was COM18 from the screen above)

On the Mac program serial you can configure it with Terminal->Settings

Program your Development Kit

In the Make Target window you should see a bunch of “targets”.  You probably have a bunch more targets, which came in your installation of WICED Studio by default, but I deleted a bunch of them so I could just see the ones that I created.

To build and program your project, double click the make target we made before.

When you look in the console you should see something like this:

And when you look at your serial terminal you will see this:

And you should also see the blinking LED!!!

Start the Bootloader

If you get this message there are three posibilites

1. The kit isn’t plugged in
2. The driver didn’t install properly
3. The bootloader wont start

Check the first two… and if that doesnt work then what this means is that the bootloader is not listening on the WICED HCI UART.  In order to fix this you need to press reset and hold down the button called “Recover”.  Then release the reset, then release the recover button.  What does this do?  Simple, when the chip comes out of reset, if the recover button is pressed, the chip starts the bootloader instead of the main application.

Here is a picture of the bottom corner of the board.  The button circled in Green is the “Recover”.  The button in Red is “Reset” and the Blue surrounds the LED circuit.

The two LEDs are labeled LED1 and LED2.  LED2 is the Red one, LED1 is the Green one.  The dip switches circled in Blue connect or disconnect the LEDs from the CYW20719.  In my case you can see (barely) that the switch is set to On.  Both of these LEDs are active LOW (0 turns them on)