Eric Laforest wrote: > How big is this getup (given your wanting to shrink things) ? I have to admit that it's bigger than I'd like it to be, but it's not too bad. The parts are soldered onto some permanent breadboard material. There are three circuits of the following sizes: BX24 (GPS, LCD, and IR interface) 3 x 1.75 inches PIC (TEMP, LED, and A/D convert) 4 x 2.25 inches PIC (Pressure and Humidity) 4 x 2.25 inches Although this sounds big, the boards are very slimline, since the parts are soldered directly onto the boards and the boards are almost paper thin. I am just now working on enclosures for this. I have one plastic enclosure that is 5.5 x 3.5 x 1 inch containing my GPS receiver, backup battery for the GPS, PT6302 power regulator, and the BX24 circuit for GPS, LCD, and IR interface. It has banana jacks for the power source, a DB9 cable for connection to the CPU, and cables for the LCD and IR decoder. I can probably also fit one of the other circuits in this same enclosure in the top half of the case, will be experimenting with that today. If it fits that leaves one extra small circuit that is 4x2 inches and only about .5 inches high. But I also have to consider that I will be adding a charging circuit very soon (within days) for the NiMH batteries. Now that I have prototyped these circuits, I may try rebuilding them in a more closely integrated way. Keep in mind that this is all prototype at this stage, and it will be streamlined as I go. I expect to end up with three enclosures (sizes estimated): - CPU enclosure (6 x 4 x 1 inch) - Power and GPS/LCD/IR enclosure (6 x 3.5 x1 inch) - Sensor and LED interface enclosure (4 x 4 x1 inch) That's not too bad considering that I will have onboard charging circuit (no battery switching) plus built-in capabilities for LCD/LED/IR/keypad, GPS, temp/humidity/barometer, and 12 A/D converters. My goal is to streamline this further by using smaller parts (for example u-blox MS1E GPS) and doing a better job at positioning the discrete components closer together on the circuit boards. I would like to end up with just two 6x4x1 enclosures for the entire system. In the future, based on a new CPU (MachZ) I'd like to then reduce that down to 4x4 inches, and keep trying to reduce the size as smaller parts become available. But given my "jacket" (actually it's now a coat) is the container for this, it works out nicely even with two 6x4x1 inch enclosures, one on each side. My new batteries (individual cells) will also be evenly distributed around my waist to reduce bulk. > Getting your body temp from an extremity is probably > not accurate at all. I agree and I am looking for a good solution for this. > Think of the places a thermometer is placed...(ick)... Yeah well they aren't going there <g> > leaves only the armpit as a workable location to get > a good measure of body temp. That's not a bad idea but comfort is a concern, and also it makes it difficult to wear since I can't just slip on the coat, I need to feed the temp sensor under my shirt. Will have to think on this more. > Finally, although the BX24/uController setup is > thrifty of serial ports, it is rather heterogenous. > Given that neither the BX24 or the microcontroller > can be reprogrammed stand-alone, wouldn't that make > it a pain to reconfigure? Not really. Consider the PICs to be black boxes, they are permanently configured to do their jobs and do it well, they will never change. The BX24 is kind of the main "router" and it will change, but programs can be downloaded via the RS232 port. The wearable itself can do the reprogramming without any extra parts. > Cost aside, why not use a small cheap, serial-programmable > SBC like the New Micro ones ... It seems to me to be > more flexible, use fewer parts, and not be dependent > on external hardware/software as the uC/BX24 are? That's a possibility, but I will still need extra parts to interface these devices unless the SBC already has lots of 12-bit A/D converters, multiplexors, and the necessary filter caps and resistors. I haven't found one yet that fits my needs. Also, part of the goal here is to experiment with the electronics and distributed processing of these parts. If this was a commercial effort I would most certainly take a more integrated approach, possibly with a small SBC add-on. But for now it's just a continuum of small experiments. -- Doug ------------------------------------------------------------ Grow your own Wearables: http://wearables.los-gatos.net What I'd like is to have you call me and my jacket answers ------------------------------------------------------------ -- Subscription/unsubscription/info requests: send e-mail with subject of "subscribe", "unsubscribe", or "info" toWear-Hard Mailing List Archive (searchable): http://wearables.blu.org please, Please, *PLEASE* don't subscribe through a forward/false domain
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