Skip navigation
1 2 Previous

Sudden Impact Wearables Design Challenge

17 Posts authored by: hlipka
(Complete list of all blog entries in this series) Leeds university asked for a short introduction and a short manual. Instead of just handing this over directly, I thought it a good idea to add this here as reference. It actually serves as a good starting point to the rest of the series... So here we go.   Skier impact monitor A short introduction Hendrik LipkaProject introduction The 'skier impact monitor' (or short 'SkiMon' as I will call it further on) is a small device designed to me ...
(Complete list of all blog entries in this series) As I already mentioned in my last post, I did not achieve all my original goals for this project. I'm not sure how this affects the outcome of the challenge, but SkiMon should also satisfy a personal need. So I would like to outline what my personal vision for this project is, what I see as next steps for continuing with development and where I see it finally. Shrinking the hardware SkiMon as it is now is still too large to be easily usable. Wh ...
(Complete list of all blog entries in this series) (Update: I added a second screen shot and data about current consumption that I forgot in the first version. It was quite late yesterday...) Since this design challenge is now  nearly finished, its about time to show what came out of all my work. There will be a second entry today outlining what can (and needs) to be improved further on - but this has a little bit more time since the next skiing season is still some months away. And its q ...
(Complete list of all blog entries in this series) This is probably the second-to-last article about my project, on the last day I will try to upload a video showing how it all works together. On the weekend I went ahead and finally  put together all the parts that lived on the different breakout boards for the last few months. I had ordered some new smaller batteries in the meantime, so I went ahead and looked for a new enclosure too. But the first task was to mount the ADXL board on to ...
(Complete list of all blog entries in this series) I have mentioned multiple times that for my project I'm using s PSoC4 MCU from Cypress. But I never explained what is so special about these chips and what made them so useful for my application. PSoC is short for "Programmable System on a Chip". Its a combination of a MCU core with a number of PLDs (programmable logic devices) and programmable analog components on a single chip. In contrast to a "normal" MCU where you write code that executes ...
(Complete list of all blog entries in this series) I already mentioned that I'm on a business trip right now, so progress was quite slow. I did some work on the PCB, more on that later. Since the trip involved flying over the atlantic ocean, I took only the Pioneer BLE kit with me. The ADXL breakout stayed at home to avoid any confusion at the airport. The goal was to work on the Android application for my phone, to get the BLE connection to he PSoC4 BLE working. Since I had no real accelerom ...
(Complete list of all blog entries in this series) Wow, I just realized that my last update was already three weeks ago. That also means I don't make fast enough progress right now. My excuse? There was a 70th birthday that needed to be celebrated (which also means a gift needs to be prepared properly), and 40th birthday that needed some preparation in advance, a road test report that needed to be written. And I wrote a bandwidth performance comparison between the TBS1102B-EDU and its smaller T ...
(Complete list of all blog entries in this series) After getting the ADXL375 to run, I needed to work on storing the acceleration history. In my test project I configured the accelerometer to use a 12.5Hz data rate since that allowed to write the measured data directly to the LCD. But for my use case I need a much better resolution (the head injury criterion integrates the acceleration over a period about about 15ms, so I need at least 1ms resolution). So I set the data rate to 1600Hz - this g ...
(Complete list of all blog entries in this series) Maybe you followed what I did write so far. If this is so, you might remember by article about the head injury criterion. There I explained how the car industry determines how severe a head impact is. One of the important part in that calculations is that only the total acceleration is needed, but not the single axes. That means I need to combine, for each reading I take from the accelerometer, all the values into the norm of the acceleration ...
(Complete list of all blog entries in this series) So this was a longer break, but the skiing vacation was really needed. Since I could not take my ADXL375 with me (though it arrived 2 days before I left) I tried to have some measurements. I was especially interested in getting some data about accelerations that happen during normal (downhill) skiing, and maybe compare them with what happens when I would fall down. So I looked through the apps that are available on Android for measuring accele ...
So today finally the big package from Farnell arrived. So here is the big unboxing: Everything neatly packed together - as usual the packaging was excellent (and the box is huge!). The encapsulation resin, together with the safety data sheet. The second resin package is still missing, I hope it will follow soon. (Btw: note the manufacturing and expiration dates...) Next we have a nice stack of boxes from Analog Devices: Time to open them up all (from top to bottom): The temperature ...
(Complete list of all blog entries in this series) Since none of the kits have arrived yet, I reckon I should have done like dougw and order a ADXL375 kit with my Farnell order (there are 20 of them on stock right now). I mostly ordered a large amount of components that should be useful for future projects. In addition I got another PSoC4 BLE kit because I wanted to modify its BLE module (more on that later) and some tools. This order shipped (to my home) within 24 hours, which is what is to be ...
(Complete list of all blog entries in this series) OK, the bad news first: no devkits from Analog have arrived yet (though Christian told me Farnell is working on them). So it looks like I won't keep my timeline for the first prototype (its less than two weeks away). But at least I made progress on the software part of my project - namely getting first results regarding the Bluetooth connection I need. Bluetooth 4.0 vs. Bluetooth Low Energy Sometimes these two terms are used as they would mean ...
(Complete list of all blog entries in this series) (Update: I finally changed the formulas to use the real time for the formula instead of 'ticks' because thats how its supposed to work. If you looked at the original version and used it, please verify your math. Thanks.) While still waiting for all the kits to arrive(did anyone get their stuff already?), I started to look into the software side of things. Over the holidays there was not so much progress, since I spend the time with the family ...
(Complete list of all blog entries in this series) As already mentioned in my last blog, I was away for a weekend (familiy birthday) and the week after for a business trip. So there was not so much time working on the project. Also, the kits have not arrived yet so I was not able to have a look at all the provided stuff. But fortunately some of the other gear arrived, so could have a look at it. PSoC4 BLE First item I got was the PSoC4 BLE Pioneer kit. My thanks goes to Cypress for providing m ...