I'm looking for a GPS for a small class project. We want the smallest GPS possible and all we really need it to do is to give us longitude and latitude values when we poll it.
I tried looking at sparkfun, but since we haven't really worked with this type of hardware before, it's hard to know which kind we really want/what parts we need.
What We Need:
smallest possible
longest battery life
only need long and lat
able to be polled from some other device such as a mobile app or website
Thanks!
there are two paths to this, one is just get a bluetooth receiver, you will be able to poll it from a mobile phone or whatever. going to likely be as big as the phone, have the battery inside, etc. not sure how long it will last on one charge.
There are other solutions designed for putting in packages being shipped, better battery life, but their goal is as data loggers and not necessarily something you can cable up and poll and likely not wireless if that is what you are after.
Now if you want to build your own, and you already went to sparkfun, here is another path.
I know that leaving links in an answer at SO is bad...This was longer than a comment and will add some more info...
You want small you can go with this
https://www.sparkfun.com/products/11571
It is a GP-635T gps receiver, if you look at the picture it really is around the size of a quarter. 50 channel. Point it up the way they tell you, antenna is built in, just power it and it works.
You will need to hook up to it. It is the serial version not usb, in either case you need a cable like this.
https://www.sparkfun.com/products/10361
This link is to a cable with 6 or 8 inch pigtails, the gps receiver comes on a board with a not so uncommon connector on it, this cable allows you get at those connections, you only need three.
The datasheet on the sparkfun page or probably just search for the part number, you need to look at the UART TTL pinouts not the usb pinouts. Yo uneed 3.3 to 5.5volts to power it pin 2, pin 1 is ground. then pin 3 is txa serial out. This is where you get your data.
these are various solutions that will work
https://www.sparkfun.com/products/9873
https://www.sparkfun.com/products/718
http://jim.sh/ftx/
some soldering may be required. The above links are various solutions between $10 and $15 for ftdi usb to serial/uart break out boards. These will include 3.3v and ground and the rx pin is the receiver for the ftdi uart, you tie that to txa on the gps unit.
What you may not know and may be interested in is that almost universally gps units do their math magic and come up with the various items time, position (2d or 3d), speed, etc. And they output this data in a serial manner. search for NMEA or NMEA-0183. The data sheet for this and any other should give an indication of the default data rate (4800, 9600, 19200, etc baud) and what messages are sent. sometimes you can change the baud rate, sometimes you cant. The ftdi chips/boards are very flexible use a usb cable to plug in the board to a computer, configure your software or a dumb terminal program like minicom or hyperterm or teraterm or whatever (no parity, no hardware flow control) and the messages will appear usually once a second. Whether it is your car navigation, handheld gps, whatever, buried inside is some flavor of gps reciever (sparkfun will give you an indication of just how many different flavors there are and their selection is just scratching the surface) that outputs serial and the software in that unit is receiving that serial data and then doing its thing (mapping, navigating, etc). As with modems back in the day the ones you find in your cell phone might have some of the software/math done by the main processor in the phone to save on money, these libraries are not generally available, when you make the deal to buy thousands or millions of units they allow you to pay for the software to go with it along with your signature on a bunch of legal documents. I assume this is the case, that is how the ones in phones are down to $10 or so where these fully contained solutions are usually $50 to $100 in single quantities and likely not a lot cheaper in quantity.
Once powered, even if it says X number of seconds hot or cold to lock it doesnt always take that, sometimes if it has to search it may still take a while, the less metal you have around (like being in a building or the center of a car) the worse it is to the point it may not lock.
if you have an older garmin street pilot (that is otherwise dead I would hate to kill one of those if it is working) you can rip it apart and likely find a sirf III or other module in there, likely a 5V not 3.3 (there are 5V ftdi based breakout usb to serial. the microftx is both 5v and 3.3, note the gps receiver linked above is also 5v or 3.3) googling will be required to figure out the pinout and such, and soldering might or might not be a challenge.
you can also find old etrex or other handhelds on ebay or wherever (that work!) and for $15 or so get a serial cable, well then you need a serial to usb likely which will also need a level shifter like a max232, you dont plug this right into a ftdi break out board, it will fry it. newer ones have usb and you can power the unit from the usb and likely see the nmea data over the usb as well.
Most of the stuff you see on sparkfun in the gps area is going to be related to these various brands and models of gps recivers that output nmea data over serial. some are 5V some are 3.3, many do not have antennas and you have to buy those separately (and get the right kind, one that plugs into the connector provided, etc). I have a number of these items and they all work just fine, some do better than others around buildings or in trees, etc. Around sparkfun you will also find lipo battery solutions and bluetooth or xbee or other wireless solutions, very quickly if you need wireless, I think you will find just buying an off the shelf solution is best. I have had my eye on the garmin bluetooth thing google
Garmin GLO Portable GPS and GLONASS Receiver
it is about $99. I have not pulled the trigger yet so I dont know how good or bad it is, the el cheapo brands just look cheap.
Of course, a smart phone has both wireless and a gps and you can get a lot of used phones for cheap on ebay. Ios and android. You could "just write an android app" and put it on the phone and use one of the wireless interfaces built into the phone. It will chew through the battery yes, how fast? who knows.
Related
I am a physicist, and I had a revelation a few weeks ago about how I might be able to use my personal computer to get much finer control over laboratory experiments than is typically the case. Before I ran off to try this out though, I wanted to check the feasibility with people who have more expertise than myself in such matters.
The idea is to use the i/o ports---VGA, ethernet, speaker jacks, etc.---on the computer to talk directly to the sensors and actuators in the experimental setup. E.g. cut open one side of an ethernet cable (with the other end attached to the computer) and send each line to a different device. I knew a postdoc who did something very similar using a BeagleBone. He wrote some assembly code that let him sync everything with the internal clock and used the GPIO pins to effectively give him a hybrid signal generator/scope that was completely programmable. It seems like the same thing should be possible with a laptop, and this would have the additional benefit that you can do data analysis from the same device.
The main potential difficulty that I foresee is that the hardware on a BeagleBone is designed with this sort of i/o in mind, whereas I expect the hardware on a laptop will probably be harder to control directly. I know for example (from some preliminary investigation, http://ask.metafilter.com/125812/Simple-USB-control-how-to-blink-an-LED-via-code) that USB ports will be difficult to access this way, and VGA is (according to VGA 15 pin port data read and write using Matlab) impossible. I haven't found anything about using other ports like ethernet or speaker jacks, though.
So the main question is: will this idea be feasible (without investing many months for each new variation of the hardware), and if so what type of i/o (ethernet, speaker jacks, etc.) is likely to be the best bet?
Auxiliary questions are:
Where can I find material to learn how I might go about executing this plan? I'm not even sure what keywords to plug in on Google.
Will the ease with which I can do this depend strongly on operating system or hardware brand?
The only cable I can think of for a pc that can get close to this would be a parallel printer cable which is pretty much gone away. It's a 25 wire cable that data is spread across so that it can send more data at the same time. I'm just not sure if you can target a specific line or if it's more of a left to right fill as data is sent.
To use one on a laptop today would definitely be difficult. You won't find any laptops with parallel ports. There are usb to parallel cables and serial to parallel cables but I would guess that the only control you would have it to the usb or serial interface and not the parallel.
As for Ethernet, you have 4 twisted pair with only 2 pair in use and 2 pair that are extra.
There's some hardware that available called Zwave that you might want to look into. Zwave will allow you to build a network of devices that communicate in a mesh. I'm not sure what kind of response time you need.
I actually just thought of something that might be a good solution. Check out security equipment. There's a lot of equipment available for pc's that monitor doors, windows, sensors, etc. That industry might what your looking for.
I think the easiest way would be to use the USB port as a Human Interface Device (HID) and using a custom built PIC program and a PIC that includes the USB functionality to encode the data to be sent to the computer and in that way be able to program it independently from the OS due to the fact that all mayor OS have the HID USB functionality.
Anyways if you used your MIC/VGA/HDMI whatever other port you still need a device to encode the data or transmit it, and another program inside the computer to decode that data being sent.
And remember that different hardware has different software (drivers) that might decode the raw data in other odd ways rendering your IO hardware dependent.
Hope this helps, but thats why the USB was invented in the first place to make it hardware and os independent.
I need to read GPS coordinates using a VB.NET program directly from a GPS device connected to the computer via USB (bluetooth also OK but prefer USB). My constraints are:
The computer running the software is NOT connected to the internet. It is a stand-alone machine in a moving vehicle.
I need to be able to read GPS coordinates from the device while the vehicle moves and use the device to perform location-aware queries on a local database
The GPS device can be anything (e.g. Garmin GPS or GPS card without display), as long at it can be purchased off the shelf or over the internet.
The user group for this solution is quite small (about 40 users).
I have already checked out GPSGate (http://gpsgate.com/) and emailed my requirements to them. They replied, and I quote: "I am sorry but we have no product for you." (end of reply).
I also checked out Eye4Software) and tried using their demo product but it does not pick up my Garmin Nuvi via USB. They responded to my questions but unfortunately their OEM product is an ActiveX dll and I am looking for a .NET based solution.
So if anyone has a "home-grown" solution based on the .NET framework, that can be easily duplicated, I would really appreciate it. Many thanks!
Most of the USB GPS pucks will speak a standardized protocol called NMEA 0183. There are several .net protocols out there that decode this protocol, see here for some pointers to get started.
So, if when shopping around you just check that the device is able to generate NMEA you should be up and running in a minimum of time, and at a reasonable cost.
EDIT: a "gps puck" is a GPS receiver shaped more or less like a hockey puck, like this one
For in-car use there are specific versions that can be fixed onto the vehicle's roof
They are pretty common (many online shops carry them) but select them based on the chip that's inside, the popular Sirf Star 3 is still a solid performer, stable and accurate. I haven't had the chance to play with its successor, the Sirf Star 4 yet, and I'm not implying these are the only good chips around, only that I got most experience with this chip.
I have a photocell that gives me the intensity of light in voltage. I want to add a unique number (that I can hard-code on the chip) along with the photocell info and send in a format I can read using a digital computer (Arduino). Any suggestion when I can start?
Sounds like you want to shop for a cheap micro controller that's easy to work with, has an ADC, and a small amount of flash memory. Almost every silicon vendor will claim to have something meeting that requirement, what you are familiar with and can easily buy in appropriate quantities may matter as much as the technical details of the offering. If you already have an arduino, another atmel part such as one of the 8-pin attiny's might be attractive.
You write a little program with a loop that reads the photocell through the ADC, bundles it with an ID number which you store in the flash beside your program, and ships it off through something like a serial port to whatever system needs the information.
Serial port can be a UART peripheral or bit-banged in a software timing loop. For short runs people often skip the line driver/receiver on each end and signal at logic voltage rather than the higher voltage (and inverted sense, the drivers/receivers invert for you) of the RS232 spec. Or you can use other schemes, synchronous ones like SPI or I2C being popular as well.
You might want to look at maxim one-wire bus devices.
They share a bus connection and ground and your ardunio can interrogate the bus.
Each device has a unique identifer and can be read.
The DS2438 is a cheap member of the family that can measure voltage.
(The DS2450 was a quad A/D converter but it was a buggy chip and is now obsolete.)
Ardunio drivers at http://www.arduino.cc/playground/Learning/OneWire
It seems that a lot of small business people have a need for some customized embedded systems, but don't really know too much about the possibilities and cannot quite envisage them.
I had the same problem when trying to explain what Android could do; I was generally met with glazed eyes - and then I made a few demos. Somehow, being able to see something - to be able to touch it and play around with it – people have that cartoon lightbulb moment.
Even if it is not directly applicable to them, a demo starts them thinking about what could be useful to them.
The sort of person I am talking about may or may not be technical, but is certainly intelligent, having built from scratch a business which turns over millions.
Their needs are varied, from RFID or GPS asset & people tracking, to simple stock control systems, displays, communications, sometime satellite, sometimes VPN or LAN (wifi or RJ45). A lot of it needs a good back-end database with a web-site to display, query, data-mine …
So, to get to the question, I am looking for a simple project, or projects, which will cause that cartoon lightbulb moment. It need not be too complicated as those who need complicated solutions are generally tech-savvy, just something straightforward & showing what could be done to streamline their business and make it more profitable.
It would be nice it if could include some wifi/RJ45 comms, communicate across the internet (e.g not just a micro-controller attached to a single PC – that should then communicate with a server/web-site), an RFID reader would be nice, something actually happening (LEDs, sounds, etc), plus some database, database analysis/data-ming – something end-to-end, preferably in both directions.
A friend was suggesting a Rube Goldberg like contraption with a Lego Mindstorms attached to a local PC, but also controllable from a remote PC (representing head office) or web site. That would show remote control of devices. Maybe it could pick up some RFID tags and move them around (at random, or on command), representing stock control (or maybe employee/asset movement within a factory or warehouse (Location Based Services/GIS)), which cold then be shown on the web site, with some nice charts & graphs etc.
Any other ideas?
How best to implement it? One of those micro-controller starter kites like http://www.nerdkits.com/ ? Maybe some Lego, or similar robot kit, a few cheap RFID readers … anything else?
And – the $409,600 question – what's a good, representative demo which demonstrate as many functionalities as possible, as impressively as possible, with the least effort? (keeping it modular and allowing for easy addition of features, since there is such a wide area to cover)
p.s a tie with an Adroid slate PC would be welcome too
Your customers might respond better to a solid looking R/C truck which seeks RFID tags than to a Lego robot. Lego is cool, but it has a bit of a slapped-together 'kiddie' feel.
What if you:
scatter some RFID tags across the conference room.
add a GPS & wifi transmitter to your truck.
drive the truck to the tag
(manually - unless you want to invest a lot of time in steering algorithms).
have a PC drawing a real-time track of the trucks path.
every the truck gets within range of the tag, add it to an inventory list on the screen, showing item id, location, time recorded, total units so far.
indicate the position of the item on the map.
I'd be impressed.
Is it 'least effort'? I don't know, but I'd hope that if this is the type of solution you are pitching, that you already have a good handle on how to read GPS and RFID devices, how to establish a TCP or UDP connection with wifi, how to send and decode packets. Add some simple graphics and database lookup, and you are set.
Regarding hardware, I don't have any first hand experience with any of these, but the GadgetPC Wi-Fi G Kit + a USB RFID reader + a USB GPS reciever looks like a nice platform for experimenting with this.
Many chip manufactures have off-the-shelf demo boards. Microchip has some great demo boards for TCP/IP communications on an embedded system. I haven't seen one yet for RFID. Showing potential customers some of these demos could get them thinking about what is possible.
USBCELL rechargeable batteries - charged using the USB port
These came out a while back and are worth the money, in my opinion.
I searched for software specifically made to monitor the battery level of USBCELL batteries and got nothing. There are some USB port monitor programs out there which might tie in somehow, but they could be unrelated also.
Anyway..
Is it possible to write a program that tells you the battery level of the USBCELL when its plugged in and is charging?
EDIT
If it makes any difference, the batteries have status lights that turn on when plugged in.
There is nothing to install (optional or required) to get these to work.
its USBCELL man here
Yes regular versions have embedded circuitry, though we do make a special USBCELL version (mainly currently for corporates), that is branded and has a downloadable USB charge monitor - that can carry cross promotions/discount codes. This is programmable, but not in the general retail version. Regular packs can also be branded for events, www.usbcell.com/customize.php
In the meantime, there is a special christmas USBCELL pack for gamers - http://www.usbcell.com/product/13 which is great for gifts
regards
USBCELL EcoMan
I don't have these batteries, nor have I used them, but the most likely situation is that there is internal circuitry inside the batteries that decides whether to pull power from the USB port.
A "normal" battery charger works the same way in that:
if there is power and the battery is not charged, draw power to charge the battery;
else do not draw power.
So, it is quite unlikely that you'll be able to monitor the battery's voltage, as there should be no reason for the battery to "communicate" upstream to the computer via USB.
Unless these batteries have a proprietary protocol to communicate their status, you are out of luck.
The standard specifications (E/O/UHCI) do not provide for any information beyond the "Port Power" bits to indicate that the hardware is supplying power to the port (not if its being drawn by the device).
Some embedded systems offer more extensive information, but it comes from custom on board logic. (Usually a power circuit connected to the USB port, and not part of the actual USB controller).
The USB Battery Charging 2.0 specification, should address these issues. But it will be quite a while before products supporting it hit the market.
If you do find a trick, keep us posted !