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)