TI eZ430 Watch – Unboxing and Hello World

It’s been almost a month since my last post, and this is due among others, to some August holidays in France… This being the 1st week-end back in London I thought I HAD to hack something and blog about it…

While away I have received the eZ430 Chronos Development Tool / Watch from Texas Instruments (have I ever mentioned how great their service is, how quick and free the delivery, etc. … !? ) and therefore had to put aside my Android / IOIO related projects, and delve into this new gadget !

1. First impressions

TI eZ430 Watch Box

The packaging looks good, as good or even better than “real” watches… !

TI eZ430 Watch opened box

TI eZ430 Watch box contents

The contents are quite impressive, and TI seems to be taking these eval kits quite seriously : not only they include the USB programmer / debugger and an USB wireless access point for remote communication, but even a screwdriver and a couple of spare screws…

Have I mentioned that this kit costed me only 25$ (on sale from the original 50$) including free shipping to the UK !?  I know it’s all about advertising their products, but still… THANK YOU TI, this is a lot of stuff for ~ 15£ !

Now let’s get down to business and try to program this “beast”…

2. Connect the hardware

This is quite easy, and here’s how it looks with the internals exposed:

TI eZ430 Watch Internals

And now connected to the USB programmer / debugger :

TI eZ430 Watch Connected to the PC

3. Software environment

Now the hard stuff commences…

First look at the “Sports Watch” code (basically the firmware that the watch comes with) reminds me why I’m a Java programmer by trade…

Then I install the IAR development environment and all of a sudden memories from high school rush back to my mind… haven’t these guys notices we’re in 2011 !

I can’t even seem to be able to open an existing project… lol…

I try Code Composer Studio… much better, Eclipse based… Java rocks indeed, at least for the IDE !

Code Composer Studio - TI eZ430

Ok, I know that I’m just a newbie when it comes to embedded electronics and that IAR is probably one of the best tools out there, but hey I want to have fun, I’m not paid to do this ! It’s enough that I have to program these little marvels in C and that even the slightest string manipulation takes 5 lines of code, I want to enjoy my hobby !

One issue worth nothing is also the general slowness of both the compilation and the download of the firmware to the eZ430. It takes around 1min 20secs even for the slightest change to get re-compiled and transfered over.

 

4. My first program

All I want to do is create a new mode on the watch that simply displays “Hello World”. To make things slightly more complex, and because there are not enough digits, I want the text to scroll.

I struggle a couple of hours on a Friday night but finally start to appreciate TI’s code… it’s quite clean and well organised, in some sort of state machine.  All I need to do is replicate the already existing code for the “acceleration” mode (the one that periodically reads the accelerometer chip and displays the values on the screen).

1. the code for the new MODULE

The HEADER - trandi.h

#ifndef TRANDI_H_
#define TRANDI_H_

// ******************************************
// Defines section
#define TRANDI_MODE_OFF		(0u)
#define TRANDI_MODE_ON		(1u)

// ******************************************
// Global Variable section
struct trandi
{
	// TRANDI_MODE_OFF, TRANDI_MODE_ON
	u8			mode;
	// Data to display
	u8  		msg[20];
};
extern struct trandi sTrandi;

// ******************************************
// Extern section
extern void reset_trandi(void);
extern void sx_trandi(u8 line);
extern void display_trandi(u8 line, u8 update);
extern u8 is_trandi_active(void);
extern void do_trandi_random(void);

#endif /*TRANDI_H_*/

The IMPLEMENTATION – trandi.c

// ******************************************
// Include section

// system
#include "project.h"

// driver
#include "display.h"
#include "vti_as.h"

// logic
#include "trandi.h"
#include "simpliciti.h"
#include "user.h"
#include "string.h"

// ******************************************
// Global Variable section
struct trandi sTrandi;

// ******************************************
// Extern section

// ******************************************
// @fn          reset_trandi
// @brief       Reset / INIT trandi data.
// @param       none
// @return      none
// ******************************************
void reset_trandi(void)
{
	// Reset state is not active
	sTrandi.mode = TRANDI_MODE_OFF;

	strcpy(sTrandi.msg, (u8*)"TRANDI HELLO WORLD  ");
}

// ******************************************
// @fn          sx_trandi
// @brief       Button UP does nothing for now...
// @param       u8 line		LINE2
// @return      none
// ******************************************
void sx_trandi(u8 line)
{

}

// ******************************************
// @fn          display_trandi
// @brief       Display routine.
// @param       u8 line			LINE1
//		u8 update		DISPLAY_LINE_UPDATE_FULL, DISPLAY_LINE_CLEAR
// @return      none
// ******************************************
void display_trandi(u8 line, u8 update)
{
	if (update == DISPLAY_LINE_UPDATE_FULL)
	{
		display_chars(LCD_SEG_L1_3_0, sTrandi.msg, SEG_ON);
		display_symbol(LCD_ICON_HEART, SEG_ON_BLINK_ON);

		// Set mode
		sTrandi.mode = TRANDI_MODE_ON;
	}
	else if (update == DISPLAY_LINE_UPDATE_PARTIAL)
	{
		display_chars(LCD_SEG_L1_3_0, sTrandi.msg, SEG_ON);
	}
	else if (update == DISPLAY_LINE_CLEAR)
	{
		display_symbol(LCD_ICON_HEART, SEG_OFF);

		reset_trandi();
	}
}

// ******************************************
// @fn          is_trandi_active
// @brief       Returns 1 if trandi module is currently active and needs doing random stuff.
// @param       none
// @return      u8		1 = trandi module needs random stuff
// ******************************************
u8 is_trandi_active(void)
{
	return sTrandi.mode == TRANDI_MODE_ON;
}

void do_trandi_random(void)
{
	// Move the text
	u8 firstElem = sTrandi.msg[0];
	u8 len = sizeof(sTrandi.msg) / sizeof(u8);
	u8 i;
	for(i = 0; i < len - 1; i++) sTrandi.msg[i] = sTrandi.msg[i+1];
	sTrandi.msg[len - 1] = firstElem;

	// Set display update flag
	display.flag.update_trandi = 1;
}

2. modify the main MENU

In the menu.c define this new structure

// Line1 - Trandi secret function
const struct menu menu_L1_Trandi =
{
	FUNCTION(sx_trandi),				// direct function
	FUNCTION(dummy),					// sub menu function
	FUNCTION(display_trandi),			// display function
	FUNCTION(update_trandi),			// new display data
	&menu_L1_Alarm,
};
u8 update_trandi(void)
{
	return (display.flag.update_trandi);
}

Add it to the chain of L1 menus, after the “Time” one, like so:

const struct menu menu_L1_Time =
{
	FUNCTION(sx_time),			// direct function
	FUNCTION(mx_time),			// sub menu function
	FUNCTION(display_time),		// display function
	FUNCTION(update_time),		// new display data
	&menu_L1_Trandi,
};

3. modify the MAIN logic

In main.c , update init_global_variables() with a pointer to the new menu (if we want it to be displayed by default) and a call to reset_trandi().

void init_global_variables(void)
{
	// --------------------------------------------
	// Apply default settings

	// set menu pointers to default menu items
//	ptrMenu_L1 = &menu_L1_Time;
	ptrMenu_L1 = &menu_L1_Trandi;
//	ptrMenu_L1 = &menu_L1_Alarm;
//	ptrMenu_L1 = &menu_L1_Heartrate;
...................
	// Reset acceleration measurement
	reset_acceleration();

	// Reset / init trandi stuff
	reset_trandi();

	// Reset BlueRobin stack
	reset_bluerobin();
}

Also add if (request.flag.trandi) do_trandi_random(); in process_requests().

4. update the TIMER calls to enable scrolling

There’s plenty of stuff in timer.c and we need to add a trigger on one of the periodic events, so that the trandi module gets “woken up” periodically and moves the custom string left.

Initially timer.c is EXCLUDED from the build, simply because I’m using the Core Edition of CSS which limits the max size of the code compiled (have I told you how much I love Arduino and the Open Source community !? ). However I could easily add back this file to be compiled with the others, without going beyond the limit … hooray…

In TIMER0_A0_ISR() (this is called every second which is really what we want !):

	// Send a signal / do some random stuff every second on Trandi, WHEN enabled
	if (is_trandi_active())
	{
		request.flag.trandi = 1;
	}

	// If BlueRobin transmitter is connected, get data from API
	if (is_bluerobin()) get_bluerobin_data();

And that’s it ! The text “TRANDI HELLO WORLD” scrolls on the L1 display ! (notice that understandably there’s no easy way to fit a “W” in a 7 segments digit, so it’s not displayed correctly, I get a “-” instead…lol..;) )

At the end of the day, it’s not terribly complex, it works and it took me only about half a day to get here…

If you’re reading this, then thank you for your patience and interest, and please don’t forget to leave your feedback which would be more than appreciated !

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