voelker

Hi,
 
i'am proud to present my latest creation, the launchpad based geocache box. Some of you may have read the story of the original reverse geocache puzzle (http://arduiniana.org/projects/the-reve ... he-puzzle/). I was looking for a gift to build for this christmas and i decied to build my own geocache box. I first thought of using an ARM micro-controller but the launchpad with an msp430g2553 seemed like a perfect fit. I dug into my electronic junk box and found a bluetooth gps module and a servo. I ordered a lcd display (3v compatible) and a switch and i was good to go !
The box is a wooden box on which i drew a wind rose using my soldering iron (pyrography) in which i stuffed all the electronic in the lid.
I hacked the bluetooth gps module to get a serial output, and in addition, it provides a 3v regulated power supply, a battery charger and the raw battery voltage. The gps is connected to the MSP430g2553 uart, the display is connected to the I2C port (USCIB0) and a GPIO drives the servo. The unregulated supply power the display backlight and the servo. In addition a reed switch is used as a secret backdoor.
You can download the code at http://code.google.com/p/msp430-reverse-geocache/.
I will provide schematics and a video asap (some pictures are attached to this post).
 
When fisrt powered the box display an hello message and then show waiting for gps signal. When the gps signal is acquired, the display shows the distance and bearing to the target. When the target is reached, the display shows a congratulation message, and loads the next target (there is seven target to reach). When all targets are reached the lid opens and reveal the true gift. Then the box can either be used as a development kit, or you can put something in it, close it and it will remain closed for one year just displaying the current date and time.
 
EDIT: now with the video !

 
EDIT:
ASCII schematic rocks !

Hi,
 
i'am proud to present my latest creation, the launchpad based geocache box. Some of you may have read the story of the original reverse geocache puzzle (http://arduiniana.org/projects/the-reve ... he-puzzle/). I was looking for a gift to build for this christmas and i decied to build my own geocache box. I first thought of using an ARM micro-controller but the launchpad with an msp430g2553 seemed like a perfect fit. I dug into my electronic junk box and found a bluetooth gps module and a servo. I ordered a lcd display (3v compatible) and a switch and i was good to go !
The box is a wooden box on which i drew a wind rose using my soldering iron (pyrography) in which i stuffed all the electronic in the lid.
I hacked the bluetooth gps module to get a serial output, and in addition, it provides a 3v regulated power supply, a battery charger and the raw battery voltage. The gps is connected to the MSP430g2553 uart, the display is connected to the I2C port (USCIB0) and a GPIO drives the servo. The unregulated supply power the display backlight and the servo. In addition a reed switch is used as a secret backdoor.
You can download the code at http://code.google.com/p/msp430-reverse-geocache/.
I will provide schematics and a video asap (some pictures are attached to this post).
 
When fisrt powered the box display an hello message and then show waiting for gps signal. When the gps signal is acquired, the display shows the distance and bearing to the target. When the target is reached, the display shows a congratulation message, and loads the next target (there is seven target to reach). When all targets are reached the lid opens and reveal the true gift. Then the box can either be used as a development kit, or you can put something in it, close it and it will remain closed for one year just displaying the current date and time.
 
EDIT: now with the video !

 
EDIT:
ASCII schematic rocks !

I gave the box on the 24th and explained how everything works to the new owner. On the 25th we took the box for a ride and completed the first step using the distance and bearing information (bearing is a bit hard to understand as i have no magnetometer in the box). It worked very well (the 100m tolerance is a bit too large to reach precise waypoints), and the owner seemed very happy with it. It was for sure the best present i ever gave, as it required more than a credit card (late night working).

When i developped the code i tried to use the libc function from math.h but cos, sin, sqrt would take too much space (i still don't really understand why ..). Only the atan2 function would work fine, but i decided to use a fast implementation found on internet. More over using my own function allows me to play with precision (i 'm only doing the relative positionning with a 100m precision). Even if my function are not optimized i have no problem, as i compute the distance and bearing only at 1hz.I also have implemented my own configurable parser for the gps stream, and my own sprintf routine to fit my small 2x8 lcd. I still have problem with the LCD that sometimes freezes (i may need to reset it at some point), but i have no time to work on it ...

Here is my entry to the project of the month contest, my geocache box. This box is an MSP430 based implementation of the reverse geocache puzzle. I will give this box to one of my cousin for christmas. To get the box to open, he will have to go through seven different locations using distance and bearing information. When all the destination will be completed the box can either be used as a development kit (gps+servo+display+switch), or serve as a personnal safe that remain closed for one year.
All the code can be downloaded from http://code.google.com/p/msp430-reverse-geocache/. Video and schematic soon to come.

Pretty awesome with all the "junk" lying around. How do you load the targets in?
And again POTM entry.

That is cool!... I never thought about using GPS as the unlock code. Very awesome.

Nice. I did something similar a while ago based around a Netduino Mini. (I'm a C# coder, so that's what got me into microcontrollers.) Some of my targets used an arrow to point in the right direction, some gave distance, some just text clues, etc. It kept my 8 year old nephew entertained for an hour or so on his birthday. Project write-up here if anyone's interested.

Hi,
 
i'am proud to present my latest creation, the launchpad based geocache box. Some of you may have read the story of the original reverse geocache puzzle (http://arduiniana.org/projects/the-reve ... he-puzzle/). I was looking for a gift to build for this christmas and i decied to build my own geocache box. I first thought of using an ARM micro-controller but the launchpad with an msp430g2553 seemed like a perfect fit. I dug into my electronic junk box and found a bluetooth gps module and a servo. I ordered a lcd display (3v compatible) and a switch and i was good to go !
The box is a wooden box on which i drew a wind rose using my soldering iron (pyrography) in which i stuffed all the electronic in the lid.
I hacked the bluetooth gps module to get a serial output, and in addition, it provides a 3v regulated power supply, a battery charger and the raw battery voltage. The gps is connected to the MSP430g2553 uart, the display is connected to the I2C port (USCIB0) and a GPIO drives the servo. The unregulated supply power the display backlight and the servo. In addition a reed switch is used as a secret backdoor.
You can download the code at http://code.google.com/p/msp430-reverse-geocache/.
I will provide schematics and a video asap (some pictures are attached to this post).
 
When fisrt powered the box display an hello message and then show waiting for gps signal. When the gps signal is acquired, the display shows the distance and bearing to the target. When the target is reached, the display shows a congratulation message, and loads the next target (there is seven target to reach). When all targets are reached the lid opens and reveal the true gift. Then the box can either be used as a development kit, or you can put something in it, close it and it will remain closed for one year just displaying the current date and time.
 
EDIT: now with the video !

 
EDIT:
ASCII schematic rocks !

Hi,
 
i'am proud to present my latest creation, the launchpad based geocache box. Some of you may have read the story of the original reverse geocache puzzle (http://arduiniana.org/projects/the-reve ... he-puzzle/). I was looking for a gift to build for this christmas and i decied to build my own geocache box. I first thought of using an ARM micro-controller but the launchpad with an msp430g2553 seemed like a perfect fit. I dug into my electronic junk box and found a bluetooth gps module and a servo. I ordered a lcd display (3v compatible) and a switch and i was good to go !
The box is a wooden box on which i drew a wind rose using my soldering iron (pyrography) in which i stuffed all the electronic in the lid.
I hacked the bluetooth gps module to get a serial output, and in addition, it provides a 3v regulated power supply, a battery charger and the raw battery voltage. The gps is connected to the MSP430g2553 uart, the display is connected to the I2C port (USCIB0) and a GPIO drives the servo. The unregulated supply power the display backlight and the servo. In addition a reed switch is used as a secret backdoor.
You can download the code at http://code.google.com/p/msp430-reverse-geocache/.
I will provide schematics and a video asap (some pictures are attached to this post).
 
When fisrt powered the box display an hello message and then show waiting for gps signal. When the gps signal is acquired, the display shows the distance and bearing to the target. When the target is reached, the display shows a congratulation message, and loads the next target (there is seven target to reach). When all targets are reached the lid opens and reveal the true gift. Then the box can either be used as a development kit, or you can put something in it, close it and it will remain closed for one year just displaying the current date and time.
 
EDIT: now with the video !

 
EDIT:
ASCII schematic rocks !

Hi,
 
i'am proud to present my latest creation, the launchpad based geocache box. Some of you may have read the story of the original reverse geocache puzzle (http://arduiniana.org/projects/the-reve ... he-puzzle/). I was looking for a gift to build for this christmas and i decied to build my own geocache box. I first thought of using an ARM micro-controller but the launchpad with an msp430g2553 seemed like a perfect fit. I dug into my electronic junk box and found a bluetooth gps module and a servo. I ordered a lcd display (3v compatible) and a switch and i was good to go !
The box is a wooden box on which i drew a wind rose using my soldering iron (pyrography) in which i stuffed all the electronic in the lid.
I hacked the bluetooth gps module to get a serial output, and in addition, it provides a 3v regulated power supply, a battery charger and the raw battery voltage. The gps is connected to the MSP430g2553 uart, the display is connected to the I2C port (USCIB0) and a GPIO drives the servo. The unregulated supply power the display backlight and the servo. In addition a reed switch is used as a secret backdoor.
You can download the code at http://code.google.com/p/msp430-reverse-geocache/.
I will provide schematics and a video asap (some pictures are attached to this post).
 
When fisrt powered the box display an hello message and then show waiting for gps signal. When the gps signal is acquired, the display shows the distance and bearing to the target. When the target is reached, the display shows a congratulation message, and loads the next target (there is seven target to reach). When all targets are reached the lid opens and reveal the true gift. Then the box can either be used as a development kit, or you can put something in it, close it and it will remain closed for one year just displaying the current date and time.
 
EDIT: now with the video !

 
EDIT:
ASCII schematic rocks !

It works ! I don't feel like i understood the problem i had, but i got it working ... My first mistake was with the interrupt generated when a NACK happens. It does not set the flag UCB0RXIFG so you should avoid testing the flag before testing the UNACKIFG flag. The second thing i did was basically moving all my i2c code to the main file (insteadof having a i2c.h and i2c.c). I don't know what i changed while moving the code, but it is now working. I'll post my code soon, just need to clean it a bit.

Sorry for the bad ASCII schematic. In fact the output pin of your uc is connected directly to AIN1 and to AIN2 through an inverter (the dot on my ascii schematic). I personnaly use a single NPN transistor to make the inverter. You are right that it decreases the speed resolution, and it makes it not linear. But this method not only saves pins, it is also said to give better torque performance. I have tested this design with the MSP430g2231 + L293D for a balancing bot and it works well (even if the bot cannot keep balance at the time ...).