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Hi, I successfully added a pressure sensor to my Freerunner. The BMP085 chip from Bosch Sensortec is a small (5x5x1.5mm) chip which includes a pressure and a temperature sensor. Power and I2C is enough to get it working. I glued it next to the BT antenna. The wiki page contains some pictures: http://wiki.openmoko.org/wiki/I2C_Pressure_Sensor Sourcecode is available from http://gitorious.org/freerunner-navigation- board/bmp085 Christoph _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Wow, this is a great hack! I'm surprised if no-one else will do the same! r -- | risto h. kurppa | risto at kurppa dot fi | http://risto.kurppa.fi _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
actually i think they should already be built in...they are so cheap... can someone suggest that to the FR-Manufactuer? regs
Depends on what you mean when you say cheap. I see it listed at just under USD 10 for one sensor or the price of a 1.3 mpix camera module. It's also not as small as you would like for something you throw in mostly for fun. -- Rask Ingemann Lambertsen Danish law requires addresses in e-mail to be logged and stored for a year _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Is the 1.3 mpix camera module also $10 for a single unit? That seems remarkably good value. One would expect a pressure sensor to be much cheaper on the 1000, of course. Stroller. _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
well, my thought was just: marketshare. more features out of the box > more customers > more competition. and i dont think 10$ make adifference, not yet talking about largeqty-volumes. eg rfid: nokia announces it since years, but FR could be fo fast...im sorry, maybe im just to optimistic... regs
I was thinking about adding a rfid reader but could not find an antenna which is small enough. Probably there were other problems too.. Christoph _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
well, there are always roadblocks, but there is always a waz around them. unfortunately im not a electric-engineer, otherwise i would jump onto that. but i can tell out of experience, the (current) future relies on that. gettin rif of those stupid hanheld scanners etc would be way easier 4 everyone. and utilizing it as a boradband device makes it even more attractive...there are no boundaries. @antenna: as far as i know, it depnds on the capabilities of the chip. eg writing and regs
1) Please don't top-post in reply to a bottom-post. It makes the flow of the conversation difficult to read. 2) Please don't post to the list in HTML. Plain-text is preferable. 3) The costs of production were discussed a LOT on this list in the past, when the Openmoko team was still active. To be honest, even if the component is only $1 then it may be too expensive, as many more design and testing costs are added to the total production cost by the addition of the component. Customers will be dissatisfied if it doesn't work as expected. A large increase in market share is needed to make the addition worthwhile. Therefore the addition of a camera may be worthwhile, whereas the addition of a barometric sensor is not. However a camera requires retooling of the Freerunner's case, a surprisingly cost-prohibitive change. I think the cost of creating a new case for the Freerunner is considerably more than $10,000. I would imagine that a camera requires other components to make it work and is more complex from the design point of view. There have historically been two major complaints about the Freerunner - lack of a camera and of 3G. Either might enlarge its market share considerably, but both were rejected on cost grounds. This barometer is self-contained and connected to the i2c bus, a _relatively_ simple addition. If there is demand for the barometer - although I'm inclined to agree with Rask that there wouldn't be - then it might it be justified to add it were Brazil ever to go into Freerunner production. A 1.3mp camera would produce complaints that it's a poor specification compared to the iPhone. Hardly anyone would be grateful for the addition of the barometric sensor. TBH, if the Freerunner were in reliable, long-term production, I might be able to imagine a market for Freerunners amongst hang-glider pilots. I think a person might be able to make a living adding Christoph's sensor and selling Freerunners with ...
I thought of adding this pressuresensor and using the freerunner as a gps-varioaltimeter for flying some time ago, but I think the display wont be readable in sunlight. And i would prefer hardwarebuttons while flying. _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Here's where Open Design Hardware changes the scenario: if you have an (open) base product, you can design, produce, and deploy small changes for a special interest group at a comparably low price - a bit higher than if the change was part of the mass-produced design, but [... more horror material ...] Why bother ? Even if we assume for a moment that you can't make money selling unencumbered software, you'd have the enhanced hardware already as a kind of dongle. Also, since this would be a highly specialized niche product, I would expect customer loyalty to be high. - Werner _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Honestly? To add the barometer appears a very easy task. It involves soldering two wires, right? If you were to start a business based on this, you might charge $100 markup to make the modification but also to cover the cost of the full- time job writing and supporting the software. I think more might even be reasonable, or you might have tiered packages depending upon software features. The Freerunner is readily available mail order - if a student in your local town were to offer to upgrade the hardware for $20, sorry, I think the business would be completely undermined. And there are Linux- competent students in every town - the "dongle", as you call it, is too easily manufactured by anyone. I love & believe in Free software, but I just don't know that it's realistic to expect to make money out of it that way. Were I ever - as a sole-trader presently - to write commercial code, I would probably GPL it in my will. Rau1 remarks on the readability of the screen - he surely is far more familiar with the current state of the sport than I am, since I have not flown in 5 years. In this case it might be better to base a design on a custom Gumstix-based board and a black-and-white screen, so the discussion becomes entirely moot. Stroller. _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Strictly speaking, you need only solder the 3.3 V wire, because the rest (GND, I2C data and I2C clock) are available at the debug connector. It sure would have been easier to make addon modules, requiring no soldering from the end user, if power had been available at the debug connector. -- Rask Ingemann Lambertsen Danish law requires addresses in e-mail to be logged and stored for a year _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Yes. References (pressure sensor first, then camera module): http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1966259&k=BMP085 https://www.sparkfun.com/commerce/product_info.php?products_id=8668 -- Rask Ingemann Lambertsen Danish law requires addresses in e-mail to be logged and stored for a year _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Add an electronic compass and you have the equivalent of a high-end GPS used in all kind of outdoor sports. Xav _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Cool! can be very helpful during mountain hiking (not that GPS does not help already -- but it may not be always available) _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
I'm wondering how much battery it draws probably not much but for backing trips it might not be all that useful. Bring extra charged batteries? What do others do for backpacking trips. Seems all cellphones eat batteries and aren't smart enough to _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
In shr-settings you can set the GSM to off and conserve batteries this way. When GSM is on the normal approach is to want a cell coverage if there is any so near-constant searching is logical. It is possible to create a auto-conserving mode which turns the GSM on and let it work for some time and if there is no serving cell around turn it off for some period of time. Baruch _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
From the datasheet: The sensor uses about 0.1µA in standby and 12µA for one sample per second. If you don't need the highest resolution this gets down to 3µA per sample per second and scales linear with the sample rate. Regards, Christoph _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Cool! How accurate do you find it? This makes the Freerunner a nice mobile for glider / hang-glider / paraglider pilots. They most always carry a varioaltimeter with them, and last time I flew (some years ago) GPS was beginning to have a significant impact upon that (niche) market. The combination of barometric pressure with groundspeed allows one to easily find the optimal speed-to-fly, allowing for head- or tail-wind on a glide between lift sources (thermals). I'm sure that this sensor must be at least as accurate as those used in the cheap commercial ($250) varioaltimeters of 10 years ago, so it looks really good for this sport, if someone has the time to make a nice interface. It would be interesting (for me, anyway) to test by climbing a small hill and see if the pressure difference is reflected accurately. 30m should be a good initial test. Stroller. _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
I think I can get about 0.5m (the datasheed speaks from 0.25m and better with software averaging), but it seems that the temperature compensation is either buggy or does not work good enough. The running phone (means: not suspended) heats the sensor up and the measured pressure increases slowly. I'll try figure I know some Qt and could probably hack a simple but ugly interface, but right I will do this as soon as I can find a hill ;) First I need to figure out where the temperature dependency comes from. Christoph _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
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