Do you remember those star wars ewoks movies? This is the device the Towani Family were wearing in those movies, showing their lifesigns.
It has been 2 months now since I have ordered the cheaper heart rate sensor and unfortunately it got lost on its way here. Additionally I ordered around the Chinese National Day and I lost track of the time so now I'm overdue on my buyer protection. So I'm hoping that they will resend the sensor as soon as they read my reply today.
Some thoughts on the software, I think it will be a good idea to measure the time between pulses and send the value over the NRF24L01s and not the value of the analog read outs. Some what a bicycle computer for your heart. While writing that I just thought of connecting this project with the Open-Bicycle-Computer. Let's monitor the pulse of the bikes rotation and show the heart rate on the bicycle computer!
I'm going to order another heart rate sensor from a different seller to make sure I get one.
The coolest sensor I found with a lot of effort put in and as much open source as you can have was the http://pulsesensor.myshopify.com/pages/open-hardware - but with a price of 20 Euros it was to much for this project. Today I looked for arduino modules on ebay and this popped up http://www.ebay.de/itm/331290728104 - for 6 Euros - I could not resist!
don't feed or order them at night. So the boards for the shield came in today and I placed all the parts facing towards the arduino board instead and missed connecting almost everything with vcc. It's all connected with each other, but not with vcc :D Luckily I can fix this with a jumper wire and turn everything upside down, put the dip switches on top of the smd resistors. I'm missing pin connectors to try complete the shield, so i'm ordering these and keep it in the box until arrival.. Normally I love those purple boards, but the leds and blue dip switches are hurting my eyes.
So since my leds came in I wanted to work on this a bit and decided to design a shield for my atmega8 boards and let the leds glow with a software pwm and work on the transmission protocols.
First things first -
The bracelet is about 95% the same from the movie. It is missing those 4 dip switches, but is instead hard wired to channel 1 and I had to imrpovise about the leds. I don"t have a pulse sensor, but it would definately work as a prop the way it is right now.
As nothing ever is really done, I will get back to this after the contest.
Today my printrbot simple broke down on me, the hotend won't heat anymore - so there will be only one wristband. Meh. And I don"t have the arduino pro minis yet nor the leds so I had to improvise on the wristband. So backup strategy now will be round leds, one wristband, fake data from 2 breadboarded arduinos.
Having a slow day at work I decided to work on the pin settings and a test sketch for this set up. It really is only a blown-up blink sketch with inputs. While it does not sound like much, this is something I normally do on putting it together, realizing I failed too remember that I can't place those leds on the SPI and so on...
[updated] I integrated the code bits of the rf24 library and wrote some bits for the channel selection by the dip switch.
Today I ordered some nrf24l01 modules and some rectangular LEDs and made a first 3D print for developing the internals.