{"id":940,"date":"2014-06-06T06:34:05","date_gmt":"2014-06-06T06:34:05","guid":{"rendered":"http:\/\/192.168.3.4\/?p=940"},"modified":"2018-01-09T06:49:38","modified_gmt":"2018-01-09T14:49:38","slug":"odds-and-ends","status":"publish","type":"post","link":"https:\/\/www.cloudacm.com\/?p=940","title":{"rendered":"Odds and Ends"},"content":{"rendered":"

The Sensor Bike Helmet<\/strong><\/p>\n

I finally got tired of my old bike helmet and decided to put together a new one. \u00a0It’s been on my to do list for the past few months. \u00a0I stopped by the Fremont Recycle Cycles and asked if they had a Giro Indicator in stock. \u00a0The clerk told me they only sell those at the U-District store, but offered to show what they stocked. \u00a0I took a look and found a Uvex i-vo<\/a>.<\/p>\n

I had already installed my 808#26 camera inside the silver Giro Indicator, but it kept cutting out. \u00a0I’m not sure if the internal battery or missing lens heat sink are to blame. \u00a0Either way, the external power was messy. \u00a0The 808#26 takes a special\u00a0proprietary charging cable and I had trouble sourcing one to length.<\/p>\n

Kind of off subject, but this was a source (USBFireware.com<\/a>) of USB cables that offered custom builds. \u00a0They don’t have the power cable for the 808#26, but do for the 808#16.<\/p>\n

I decided to put it back in the box and move on with the Uvex helmet. \u00a0The Uvex uses a 808#16 camera. \u00a0This is a robust camera that I’ve field tested for over 2 years. \u00a0I’m confident it will hold up. \u00a0I dug out pits and trenches in the helmet to place all the electronics and wiring. \u00a0The lens and microphone are extended from the camera main board. \u00a0This helps conceal the devices and improves the quality of audio. \u00a0I attempted to use a 5v 200mA solar panel to offset some battery drain, but I removed it because it looks a bit much.<\/p>\n

To power the camera, I’m using a Concept Green USB battery pack that is rated for 5v at 2200mA. \u00a0My previous packs were 5v at 2000mA. \u00a0The increased capacity was a plus, but also it was smaller. \u00a0I sourced a USB cable<\/a> that will link the pack and camera, so I decided to hack the pack and embed it. \u00a0The USB port is a small circuit board that is wired into a LiFEPO4 cell. \u00a0I wired the pack board to the camera and fastened the cell to the helmet. \u00a0Everything seemed to work fine.<\/p>\n

During ride tests, I noticed that the camera kept shutting off unexpectedly. \u00a0It turned out that the pack board had a chip with thermal grease that was sinked to the USB port. \u00a0This heat dissipation was missing and I ended up frying the pack board. \u00a0I ended up\u00a0removing the old pack board, wiring, and cell from the helmet.<\/p>\n

In the meanwhile, I have another Concept Green USB pack attached to the helmet. \u00a0This time everything is stock and the power is supplied using the USB cable ports. \u00a0I’ll have to order a custom 4 inch USB patch cable. \u00a0This should tidy up the appearance.<\/p>\n

The helmet is easy to work with and I’m considering it as the platform for sensor integration later on.<\/p>\n

Powering the Helmet<\/strong><\/p>\n

I still like the hack I did with the Concept Green USB pack. \u00a0Embedding and using the port and charging circuitry inside the helmet is ideal. \u00a0Too bad about the heat\u00a0dissipation requirements. \u00a0I’ll have to get the circuitry design before I can make another attempt at it.<\/p>\n

However, the battery cell was rather simple. \u00a0I’ve sourced lithium ion cells before from BatterySpace.com for a few years now. \u00a0I used a comparison\u00a0to identifying one to use for this project. \u00a0The 808 cameras draw an average of 400mA during operation. \u00a0This gives me 5 hours of run time using a 2000mAh pack. \u00a0I found 2 possible cells to use. \u00a0The criteria to establish the better suited cell were, fail factor, price, power, weight, size, and duty. \u00a0Fail factor is a quantity of cells, so \u00a0if I had 4 cells for the pack, I had a fail factor of 4. \u00a0Power is a product\u00a0of the voltage and amp ratings which is measured in watts in hours. \u00a0Duty is how many charge cycles can be applied to the cell before it starts to degrade. \u00a0The rest are self explanatory, size is cubic mm.<\/p>\n

Here are the results for these 2 cells, LTO 1865<\/a> and the LiFEPO4 26650<\/a>. \u00a0Now it’s not too difficult selecting which one to use.<\/p>\n

\"CellRating\"<\/p>\n

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Another option for power was a solar panel. \u00a0I still have to determine the correct way to connect it. \u00a0I had picked up a couple of 5v 200mA panels at Fry’s. \u00a0One panel fits ideally on the Uvex helmet and the wiring is well protected. \u00a0It doesn’t provide enough current to power the 808 camera, but it offsets the drain from the battery. \u00a0I estimated that it would be 70% efficient on average use, this meant it will provide 140mAh. \u00a0This will extend the battery life a couple of hours, not too bad.<\/p>\n

Titanium and the Apple<\/strong><\/p>\n

My last post held so much promise.\u00a0 The Titanium platform and source code for the iPhone app Mobile Logger made me think I was on the fast track to iOS development.\u00a0 One thing after another crept up and it became clear the road was a dead end.\u00a0 First came the errors when I tried to load the TDK on my computer and run it.<\/p>\n

\"ShowStopper\"<\/p>\n

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But wait, it does end there.\u00a0 I call this a show stopper.\u00a0 I’ll need a mac to develop iOS apps.<\/p>\n

\"iOS_Dev\"<\/a><\/p>\n

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That settles that, iOS development isn’t happening any time soon.<\/p>\n

808-16 Action Camera<\/strong><\/p>\n

The folks in the trenches have it spot on. \u00a0I happened to find a feature that has been enabled with a new firmware for the 808-16 action camera. \u00a0Now this inexpensive and small 720p camera allows shots in time lapse as well as video when motion is detected. \u00a0With so much crippleware out on the web, it is refreshing to find technology heading in the correct direction for the public to use.<\/p>\n