After 8 months of design, the device has finally been completed. We presented and gave a demonstration of the device during the Northeastern University Electrical and Computer Engineering Department Capstone Competition.
The Presentation included a 14 minute speech explaining the technology, the protocols, and every aspect of the design. The last 6 minutes were used for demonstration purposes where a group member rode a stationary bike while wearing the ECG. The judges noted the slow paced music while the users heart rate rested at around 90bpm. Three minutes into the workout, he was asked to sprint on the bike, causing his heart rate to jump to 140bpm. The device gave an audio notification saying “Current heart rate 140 beats per minute” and selected a new song (Blink 182, Party Song)
After this, the device was powered down and synced with a computer to show the judges how workouts can be tracked and plotted over time.
More Images for your Viewing Pleasure
Using photoshop, I have modified existing iPod Accessory enclosures to represent what shape and size this device can be. The two selected were a Motorola wireless bluetooth headphone receiver unit and an iPod camera USB attachment
For More photos, check out the gallery
The second board revision finally came in today. It was ordered from Advanced Circuits using their free PCBArtist software. It takes some getting used to, but overall, it’s a great tool for projects like this.
As you can see, there were a few problems with the layout. The most important issue, was the incorrect pin numbering of the dock connector. For some reason, the pin numbers were swapped in some places…causing major problems. Another issue was the incorrect polarity of the RGB LED. Cathode and Anode were switched. After a few hours of rework, the boards worked great.
The boards were assembled and soldered by me by hand. I’m pretty sure that if I spent one more hour soldering this board, I would have gone cross-eyed.
More pictures for your viewing pleasure:
Click on an image to enlarge
So there have been people out there trying to hack the Apple Accessory Protocol. ipodlinux.org is one of them. Throughout this project I’ve compiled a large list of commands but needed to test all of them on various iPods to see which ones would do the trick.
Using LabView, I designed code to allow us to control the iPod via RS232 communications and log what commands did one. Below are screenshots from the LabView code.
More Screenshots…
For prototyping purposes, the first PCB board was designed using Express PCB’s free software. Three identical boards were printed and shiped for about $70. This board allowed us to fully test the functionality of the Microcontroller (Texas Instruments MSP430), USB, EEPROM, and most importantly, the iPod dock connector and protocol.
After 8 months of design, the device has finally been completed. We presented and gave a demonstration of the device during the Northeastern University Electrical and Computer Engineering Department Capstone Competition.
