PlaneMad
New Member
Hi, im sort of lost trying to figure out how to implement my graduation project idea. the goal is to design a system that will give passengers inside trains the current location of the train and other details like next station, delay, ETA etc without using a gps. i figured i could take advantage of the linearity and predictability of a train's route to build this system using simple radio communication instead of using gps systems. the focus is on low cost and scalability on a huge railway network
the principle is simple: if a train already has the information of the route preprogrammed, you just need some sort of external trigger from waypoints outside as well as knowledge of distance travelled to estimate the current position of the train.
so there will be a short range radio transmitter at every station that will continously transmit its unique 4 letter station code (for the project, its just 3bits). this is very similiar to non directional beacons used for aircraft communication.
onboard the train, the receiver will continously monitor the particular frequency for a station signal. once within range, the station code is matched to the timetable database in the microcontroller. with this info and data from the trip odometer its possible to estimate the current position of the train. the resulting info is displayed to the passengers
ive made a simple animation to illustrate the concept
**broken link removed**
**broken link removed**
ive been doing a lot of reading in the college library and ive kinda figured that fsk modulation would be the ideal choice for transmitting a 3bit code for a distance of around 2km. would this be correct? ive been searching all through the net but ive not found any circuits for what seems to be a very simple requirement. all i can find are fm circuits but i dont know how exactly to modify it for fsk. any help appreciated.
cheers
the principle is simple: if a train already has the information of the route preprogrammed, you just need some sort of external trigger from waypoints outside as well as knowledge of distance travelled to estimate the current position of the train.
so there will be a short range radio transmitter at every station that will continously transmit its unique 4 letter station code (for the project, its just 3bits). this is very similiar to non directional beacons used for aircraft communication.
onboard the train, the receiver will continously monitor the particular frequency for a station signal. once within range, the station code is matched to the timetable database in the microcontroller. with this info and data from the trip odometer its possible to estimate the current position of the train. the resulting info is displayed to the passengers
ive made a simple animation to illustrate the concept
**broken link removed**
**broken link removed**
ive been doing a lot of reading in the college library and ive kinda figured that fsk modulation would be the ideal choice for transmitting a 3bit code for a distance of around 2km. would this be correct? ive been searching all through the net but ive not found any circuits for what seems to be a very simple requirement. all i can find are fm circuits but i dont know how exactly to modify it for fsk. any help appreciated.
cheers