Thread-Ansicht
Board-Ansicht Spark727 29.05.2006, 15:21 |
Pleaseeeeeeeeeeeeeeeee HELP !!! |
Can anyone help me please, i need a schematic of a car speedometer with a DIGITAL (3 digits) AND LED display (with about 60 led\'s), what displays simultaneously. Pleaseeeeeeeeeeeeeeee help !! |
| el-haber Catania, 30.05.2006, 08:51 @ Spark727 |
Pleaseeeeeeeeeeeeeeeee HELP !!! |
Hi,what kind of Motor (Bike, Racing, OTTO, DIESEL). Which range of tunrs / minute. How many cylinders and which ignition-system. What reaction-time of display.I suppose, that this could be best realized with a microcontroler like PICAXE and 2 LED-Display-Driver M5554 (serial-IN 40Digit out). Mainly it will be a count within exactly fitted 600ms Samples.CUStefano |
| Spark727 30.05.2006, 13:51 @ el-haber |
Pleaseeeeeeeeeeeeeeeee HELP !!! |
Hi Stefano, thank you very much for your reply, 1.) The Motor, is a 6 Zylinder Otto engine, with fuel injection for a car, 2.) the range should be between 0-9.000 rpm.and 3.) Stefano, i am not realy good in digital, so i will need some help like a schematics or circuit.hope to cu againFreddie |
| el-haber Catania, 30.05.2006, 15:36 @ Spark727 |
Motormeter |
Hi,in abstract it could be like this. |
![[image]](img/uploaded/image238.jpg)
CUStefano| Spark727 31.05.2006, 13:44 @ el-haber |
Motormeter |
Hi,thanks for your reply stefano, it is a definite start.here is the design picture of the speedometer i want to build, so, all help is most welcome. |
| Spark727 31.05.2006, 13:53 @ Spark727 |
Motormeter |
Hi,sory, i made the something wrong with the upload, so here it comes (i hope. |
![[image]](img/uploaded/image240.jpg)
| papa_of_t 31.05.2006, 14:14 @ Spark727 |
Motormeter |
Hi, I made a similar tool in order to make a measure tool for an airplane propeller. I used an AVR Mega8 uC and an LCD display, but of course it is also possible to shift LEDs out. In any case there\'s some things to program, not only to \"wire\", because you need to calculate the speed from the turnings, the gear and the tire measures. Where will your speedometer get the \"selected gear\" info from ?Carsten |
| Spark727 31.05.2006, 16:05 @ papa_of_t |
Motormeter |
Hi Carsten,i was thinking maybe from the \"Flywheel\" (\"Schwungscheibe\") of the engine, but i know, soonest you change the tire size, it will not be acurate anymore, so i thought maybe from the \"Drive Schaft\" (\"Antriebswellen\"}, what is the same issue................. AND thats where i put you guy\'s in the picture, because you are much more advanced then i am (i hope so).............. i am not sure Carsten, maybe to use some sensor in the front grill of the car, like a \"Radar sensor\" ??? |
| papa_of_t 31.05.2006, 17:00 @ Spark727 |
Motormeter |
Hi,before you start thinking about the \"frontend\" (LED, design etc.) you must find a reliable way to get the speed information (maybe your existing speedometer is using such an impuls..) this is the mayor thing. Post again if you have a solution.. |
| el-haber Catania, 31.05.2006, 19:08 @ papa_of_t |
Motormeter |
Hi,am I right - the application has increased from simple Motormeter to an extensive dash-board?I was used to take a pitot-tube for the relativ velocity and speed or a radio-reflectiv sensor for ground-speed (which is the same as the absolute speed).This makes ist much easier to be independent of wheelsize and shaft-turnspeed.CUStefano |
| Spark727 31.05.2006, 21:23 @ papa_of_t |
Motormeter |
Well, here is an idea of the sensor |
![[image]](img/uploaded/image241.jpg)
and the circuit ![[image]](img/uploaded/image242.jpg)
, what we can build further on, but again, maybe someoen has already bulid something similar (what i hope), so it would help me a lot.(P.s. and if i would not have the idea of the \"frontend\", i would not have the idea to build one at all.)That\'s why i am asking for help, because i am staying at the scratch............, i been also googeling for a long time, but could not find anything like, and that\'s why i am here to ask for help.| el-haber Catania, 01.06.2006, 09:34 @ Spark727 |
Motormeter |
Hi,there are two ways of getting the amount of Engine-turns.One is to use the \'Hall-Sensor\' of recently designed Ignition-Systems or using the Interruptor-Kontakt at Ignition-Coil of older Modells. This Methode has the gap, that Iginitions come at every 2nd turn for each cylinder. So, in your case, it comes three times of real turns. (n=I/3).The other methode is to use the Hall-sensor at CAM, which Pulses with half of the Engines turns.You have mentioned a Methode of taking the turns by extra coil and Permanents directly from Motor-Shaft or behind the gearbox. (Where you have to distinguish between Vehicle-velocity (after gearbox) and Motor-turns.)A good Dashboard is also an instrument of worth-measurement, because it tells a potential vendor the mileage of the Vehicle. So anyone will asume it as \'InManipulateable\'.CUStefano |
| Spark727 01.06.2006, 18:32 @ el-haber |
Motormeter |
Hi,i was checking the hall sensor (what i was trying to attach here, but its a PDF file, and can not be attached here), and i beleive that the hall sensor is the much more reasonable solution to use.So Stefano, can you chart me a schematic for a circuit, where we can include digital and led at the same time??If you can, i am also willing to honor that (so long you leave me my shirt |
).please let me knowthanks a lot CUFreddie
| el-haber Catania, 02.06.2006, 09:04 @ Spark727 |
Motormeter |
Hi,let me think about it a few minutes.The bettered schematic is from the above one by correting direction of LED\'s and aditional drivers. The main Logikal behaviour is within the Programable Logic (PIC, R8C13, etc.).For the moment i do not have any development system for that, but will aid you further on.CUStefano |
