Saturday, December 21, 2013
Mega Fitness Software Review Project
I’m evaluating where to live for my new job: sleepy town with a 5 minute walk to work, or big centre that is a 20 – 30 minute low traffic drive. There is a lot to things to think about going forward, but the big thing I’m interested in is getting back on a training plan.
Going forward I’ll be working more on sports and fitness technology. I really want to converge my job and my lifestyle, which is something that is commonplace in new, young, vibrant companies whereas there is less of that in older corporate companies. For me, that means that work can be a bit more flexible, but I don’t mind long days or testing a piece of hardware on a bike ride on my own time. In fact, the more sports tech I have access to, the better.
I’ve found that older style corporate environments are not ideal to a more physically active lifestyle. I won’t go into specifics, but the short of it is that it can feel more accepting of smokers than runners or cyclists. In some cases a lack of a shower or an open ideology to being active means can mean there is no chance of a physically active employee.
So what does this change mean for me:
It means a dedicated training (and food) plan. While some people use exercise and training interchangeably, I think of them as distinct and very different. Exercise is great but usually less structured and focus, while a training plan means something is planned with long term vision and each workout is decided beforehand – and you fight through an off day, or use a rest day as expected.
So this gets to something I’d like to do. I’ve been using several pieces of software and I haven’t found a good summary of them, their uses, etc. I kind of want to do something similar to what Ray does with his in-depth reviews, but for online workout tracking software. The biggest challenge is that they change – so a review 3 months old might not be valid. So here is a quick review and for reference TGI = Thoughts Going Into the Evaluation.
Friday, November 29, 2013
“Do you want to build fifty in a basement, or do you…”
On Friday, the 15th of November, a piece of paper was signed which saw my work change hands taking me along with it. I don’t remember what the rest of that quote was from my first telephone call with the CEO that I nervously made from my car in a parking lot. I want to insert something like “change the world” or “change the face of cycling” or maybe it was just a larger number. I walked away from the call a little confused with a lot of thinking to do. I trust and believe in the people at this company.
I truly think this is the best thing possible route for me to take. I didn’t want to be another late and under delivering Kickstarter with production troubles due to my inexperience with outsourcing or marketing. Striking while the iron is hot is hard when you can only dedicated 15 – 25 hours a week to something and maybe a few hundred dollars a month.
As for the blog, it will remain (no posts will be deleted) but it will stop any further documentation of the development as it’s going to be under a commercial entity. There is going to be a major design change, and the final product will look nothing like what I’ve developed and conceptualized.
This is a super exciting time and I’d love to explain the new and unique ideas on the table or just how we think we can shake things up. The people I’ve met truly feel very like minded, and in a the few days with them I felt like part of the team even though we were just in the initial phases of talking.
Below are a few imaginary FAQ question about the situation and general explanations.
Monday, October 21, 2013
Cheap Arm Programmer
So you have a custom ARM Cortex-m0 (or other) board you want to program. Perhaps, like me, it’s a custom board using Nordic Semiconductors nRF51422/822/922. You may have bought an Evaluation Kit with a built in J-Link debugger. However, once you move to a custom board you now face the problem of programming it.
I bought both the nRF51422-EK and nRF51422-DK. Each kit was $100 USD. The EK did what I wanted, the DK “requires” the nRFgo development kit which is $400 dollars. What you might not know is that this board provides only power and the nRF51422-DK comes with a Segger J-Link lite. The J-link Lite is what I’ve been using to program my custom boards. I think $100 dollars for a programmer is ridiculous. My AVR was $50 dollars and that allows me to do everything.
Enter CMSIS-DAP. It seems this is intended to add debug functionality and firmware updating to embedded applications but looks like you can use it as a standalone programmer without any restrictions (like with the J-Link EDU; Cost effective but limited to Educational).
So pick yourself up a $14 Freescale Freedom FRDM-KL25Z. Cheaper than an Arduino and way more powerful with a 3 axis accelerometer, a tri colour LED and a capacitive sensor. It has two microcontrollers – the main one and a little one running OpenSDA. With OpenSDA you can load up a CMSIS-DAP firmware from Freescale and program other boards. Credit to www.mcuoneclipse.com for the idea.
Here is how:
- Cut J11 Trace. This disables programming the main KL25Z microcontroller.
- Install a 1mm pitch, 10 Pin header at J6. Little bit difficult to solder due to the fine pitch.
- Break Pin 7 off – This is the Key pin. This isn’t needed if you don’t have a blocked pin on your ribbon cable.
- Hold RST while plugging it in. This loads it into OpenSDA firmware upload mode.
- See a new drive
- Download Freescale Quickstart here and copy CMSIS-DAP_OpenSDA.S19 to the Bootloader
- Unplug and plug back in. Now Freescale is in CMSIS-DAP mode.
- Connect your custom board
- Set to CMSIS-DAP (I’m using Keil)
- Switch to SW programming and not JTAG
There are other firmwares for programming but they are locked to Freescale Devices. The CMSIS-DAP isn’t. The trade off is that you lose the Serial to USB lines on the OpenSDA programmer. Oh well.
Saturday, October 19, 2013
Random Trip to Alberta
AB Ride
As some of you may have read, I recently travelled to Alberta and I got to take my bike with me. Everyone had talked to me about riding from Canmore to Banff, but having seen the drive to Canmore from North West Calgary, it was a bit of a longer round trip plus I had to go Karting later that afternoon. A lot more after the break. Less powermeter, more adventure stuff.
Thursday, October 17, 2013
More on Accuity + Quarq
After spending a few nights dealing with the required decoupling math for the Quarq + Accuity unit I’m still not 100% there. I feel I’m 95% there, but something is eluding me.
The right measurement is dead on, within 1-3% of the Quarq.
The left measurement is another story ranging from 5 – 8% out.
What I thought was the original issue was due to the non-integrated spider and that I didn’t place the shear strain gauge deep enough down the hole. As a result it can see some of the stain caused by the torque on the right arm in the left sensor. A few ways of dealing with this:
- Reinstrument with another strain gauge (about 3 evenings of work)
- De-coupling Math (in theory short, but probably 3 evenings of work… to get right)
Essentially the math works by calculating the torque on right arm from the right strain sensor setup, and then subtracting that small percentage from the left arm. How much are we talking?
For every 1 N-M on the right arm, I can see 0.0075 N-M on the left arm. I messed up the math earlier which caused each arm to work nicely independently but together they didn’t work right which resulted in a significantly reduced measurement of power and the balance skewed 100% right.
Now that this is all sorted I have the problem that the Left sensor is reading low, both independently and concurrently. I can artificially dial it into the Quarq but I don’t believe that is the correct thing to do.
Question I’m trying to determine. Could the loss of torque due to the bottom bracket bearings be affecting the calibration? Would the Quarq have been calibrated for each side and then averaged? Am I missing something?
I was checking for force sensitivity due to twisting the arm and at best I could muster was adding more force, not losing it.
Other things of note
The small Sunnto style m-ANT (tiny) stick DOES NOT WORK with the old .NET libraries. You need the latest ones! Having realized that I’ve started using my double powermeter recording software with an AP1 or AP2 usb stick. I dislike how it sticks out on my laptop though. I think I just need to replace a .DLL file but haven’t tried it.
To summarize:
- Carbon fibre remaining linear; multiple calibrations resulted in nearly the same numbers (18.62 versus 18.82 bits/N-M) with multiple points.
- There is some permanent strain in the carbon caused somewhere between flying it from ON to AB. Didn’t affect calibration really.
- Bad decoupling math was the problem with it not functioning correctly in AB and resulted in swapping to my Aluminum Rival Crank which still works very well.
- Still investigating the small percentage difference between prototype and Quarq
- m-ANT stick requires new libraries for .NET development
- Samsung commits to ANT+; At least on flagship
- If you have an idea on why my calibration might be off write me here
Personal notes: I wish that the Nexus 5 will be reasonably priced and have ANT+.
Tuesday, October 15, 2013
Short Break–Back Very Soon
There have been a lot of things going on in the background which has prevented me from posting anything for the last few weeks. I’m currently refining the Quarq + Accuity unit. It’s working well but there are some force sensitivity investigations that I want to conduct and I might want to reinstall the left leg sensing strain gauge.
Upcoming potential posts
- Carbon, carbon, carbon – the good and bad. Surprisingly little bad thus far.
- My interview with Auto21 which funded my Masters research. Canadian Automotive research at it’s finest
- Potentially a biweekly podcast with some other good folks interested in cycling and power (still working out details).
- Strain gauges and some issues
- Trip to Alberta – Less bike related and didn’t make it to the ANT+ symposium but some fun things to do in AB. Must cycle Banff and Canmore next time. This time was just outside Calgary area cycling. Also, Go-Karts.
Monday, September 30, 2013
Quarq or Accuity
Quarq or Accuity? Guess which is which.
Testing right side then left side!
Close, almost perfect. Going back to check calibration data. This one requires some "Decoupling" math which I'll get into when I do a serious post soon. Very very busy week.
