i'm gonna be getting my license soon, and since a friend of mines car was stolen recently, i was trying to think of some security system i could implement (i was seriously considering a 20 lb. propane tank with flamethrowers on the sides like a car i saw on the net, but my mom said no flamethrowers on a car shes insuring... bitch...) i want to do something like changing a gps unit so i can use a handheld unit to see where my car is, with a gps antenna on the car somewhere. sort of like tricking the gps to think it's in the car, but really isnt. can this be done somehow?
Cell phone, microcontroller, GPS hidden in the car If your car is stolen then you phone up the cell phone, or send it a message or whatever, depends on how you have programmed the uC. The uC gets the gps coords from the GPS and sends them back to you. In the UK there are a few other options: - Tracker system which the police can use to find your car - Cell companies now let you track your phone so you would not need the GPS or the uC, just a hidden phone. I don't know what the resolution is. Of course none of these systems work if A) They find the contraption B) They drive outside cellphone range C) They drive it into a shipping container (I beleive that this is standard pratice for the organised gangs)
Hey Rod10k, have you got any recommendations for what GPS module to use for this? Preferably one that does height above sea level. Also, is there an easier way to make it send the text than wiring up the keys to the uC? ch424
http://www.coolcomponents.co.uk/ These guys have a small GPS unit which you could intergrate directly with a uC. They also have a GPRS module which you could use instead of a mobile phone. The price is quite high tho. You can really pick up any GPS unit which is capable of outputting NMEA serial data, I think most of the etrex ones can, and they are quite cheap. The one from the people above is cheaper than I have ever seen an etrex tho. As for the mobile phone I would get something really cheap from ebay, say a T28 or something and a data cable for it. You should then be able to send serial commands to the phone via the cable to make it do things like send text messages and call phone numbers. Then pick up a pay as you go sim card and stick it in the phone. Set the uC to message you every month or so just to say "I am still alive" and also to keep your sim card alive. BTW I have no affiliation to cool components, I have never ordered from them but they do look to have some nice stuff Edit: Check out this website for an example of what I mean http://www.serasidis.gr/circuits/smscontroller/smscontroller.htm It controls a set of relays and is one direction only but it contains a link to the instruction set which explains how to send messages using the same interface
Awesome! £40 for a GPS module! I found the mfr. page on it, here, but I don't get what the interface+protocol is (UART, SPI, I2C) to read data off it. Any ideas? ch424
Interestingly it does not actually say anywhere. I am guessing that it is not SPI because there is no clock line, same for I2C. Also its quoted baud speed of 4800 is quite slow for either of those protocols, I am guessing that it is rs232 and so you could take it straight into the UART. Cannot find any information about input tolerance so you may need level conversion..
but, if you power it by car battery, then if they unhooked the bettery, and when the cell battery died, it would be over, this is a common way to get around onstar tracking, unhook the battery and they cant gps track onstar, also works if you know where the transmitter is and disable it, cut a wire/remove it/ect....
i could wire a few li-ion packs in parallel to increase battery life, and if i had the phone run off of the car battery, and the li-ion ones be backups, it would give me more than enough time to go home, arm myself, and find the SOB. (maybe break every finger and toe he has) and then call the cops. street justice is not as much fun if you are not wielding a shotgun, trust me. I'm American.
Even better would be to have an alarm type keyfob (You could also have an alarm but it is not a requirement) When you arm the system it takes a GPS lock of its current location. If the power is cut, or it moves from that location it sends you a message saying help me I am being stolen...
Dammit, not fair, I should stop reading these forums, so far on my list of stuff to do I have: USB to gamepad adaptor adjustable bench powersupply Oscilloscope (hard!!) Networked PIC and now PIC to t68 connection which I have no use for but seems like a fun thing to try, and should not take very long either...
Someone did that already... can't you PM them? The newest PICs can take 300k samples/sec! Use an 18f2550 (loads of 10-bit ADCs) and its USB connection... HOW!? ch424
300ksamples is not very fast for a comercial scope, I am thinking more like 100Msampes. I want to make something with similar functionality to the TDS1000 series. These things have stuff like 100MHz bandwidth. That is going to require some major work. I know that there is something called bitscope which uses a PIC, but that is just for control, the real work is done by a CPLD, I think I will have to go a similar route. There is more information on fpga4fun.com and I think I will follow a similar route. The cost is quite high but then so are those scopes from Tek (roughly 1000). As to the networked pic, microchip have just released a combined MAC and PHY which has an SPI interface so it makes adding ethernet not that hard. The software is quite a lot more complex but thats half the fun. I am not sure what I am going to do with it but I will open a thread here if I cannot think of something good.
Way I'd do it is use a EM-406 GPS module from sparkfun.com (they ship overseas) and a GM862 with python interpreter and a suitable cell antenna. Total cost about $200. I believe the GM862 can take input directly from the EM-406, but if not an AVR or PIC could easily handle the work. The EM-406 uses the SIRF III chipset which means you'll almost always have a signal. The GM862 is a GSM cell module that you just need to plug a SIM card into.
nleahcim, the EM-406 is what Rod10k linked to in post #4 in this thread -- where it's cheaper, and in the UK. Quite a task! I used one a few months ago that does 10Gsamples I'll take a look at that MAC/PHY stuff... Thanks, ch424
cnleahcim, the EM-406 is what Rod10k linked to in post #4 in this thread -- where it's cheaper, and in the UK.[/QUOTE] i think spark fun is going to be my route. i think nleachim gave me a gameplan
Hi - I've actually used this device. Like most GPS units it has a straightforward 5V serial output from a UART at various baud rates. Very very simple to interface.. Needs level changing circuit to connect it with your PC's RS232 levels though. Data comes out in NMEA format - easy to read and ASCII www.coolcomponents.co.uk have a bit of test software on their site which immediately shows you info from the module.
Might want to consider insurance. I got a big discount for having Lojack and it pretty much paid for itself after a year or two. If you homebrew it, you probably won't get a break.
