DIY Gauges ?anyone?
DIY Gauges ?anyone?
Soon I willl have a laptop in my car,my thought is to have some indicator inside my car (EGT , Fuel pressure , Oil Pressure, Oil Temp, espically Knock Sensor and EGT) ,butI don't like the gauges everywhere in my car, so my plan is to buy some pressure sender, EGT sensor , Knock Sensor, and I will build a unit that read 0-5V for those sender input in to the computer , I can also input the MAF signal in for dyno use ,of cuz the unit can be interface with my laptop (serial port or USB), and i will have to ask my friend to program a software for this. have anyone done it on here? any input, comment , idea , please let me know, I would like to hear from u . Thank you
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whiterps13
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It definetly ain't that hard. The tricky part is the interface between the analog volt signal and the laptop. How is it you are going to do this? You mention you will be building a unit, I'm guessing using some kind of uP to convert the analog signals into a data stream through USB or serial as you also stated. There are some very good uPs out there with 4-16 analog inputs.
You just need to have the software read the serial port periodically, maybe send a signal to the uP to start streaming, read the data and display it.
One other question, thing you might wanna consider. What software is ur friend using if we can know? Cause the few softwares I've played with don't have very good displaying objects (meters, clocks, graphs) so if he can get some good controls for displaying that would be best. Specially for the knock meter since the signal is just garbble unless you filter it or display it on a time graph.
You just need to have the software read the serial port periodically, maybe send a signal to the uP to start streaming, read the data and display it.
One other question, thing you might wanna consider. What software is ur friend using if we can know? Cause the few softwares I've played with don't have very good displaying objects (meters, clocks, graphs) so if he can get some good controls for displaying that would be best. Specially for the knock meter since the signal is just garbble unless you filter it or display it on a time graph.
sensor --> signal line (0~5V output) --> numerical encoding circuit (device) --> USB/serial port --> computer program --> output on screen
I found a chip for analog to digital convertor so far , but need further reseach for the stablity of the chips, about the program, I'll use visual basic to program with . What I am worry is that would a Serial port handle the real time display? I may conside of using USB instead.
I found a chip for analog to digital convertor so far , but need further reseach for the stablity of the chips, about the program, I'll use visual basic to program with . What I am worry is that would a Serial port handle the real time display? I may conside of using USB instead.
Nah don't worry. Serial port speeds range from 2400kbps to 9600kbps so real time display ain't a problem. I would worry, though, about VB. It ain't very good at real time display (or maybe I'm just not good programming :pface ) but I do know that it doesn't have very good display controls, so with the base VB package you are mostly limited to numerical displays maybe a graph display, but the Excel graph capability in VB is very limited when it comes to real time since it's a very processor needy control.
Just make sure to get a ADC chip with enough inputs. Although it would be best to get some sort of uC to read the analog signals and send them through serial stream on a single chip, less wiring less things to go wrong. Also make sure to have enough inputs, as I said before, cause you don't want to have to wire voltage follower circuits and make the uC switch between them.
Just make sure to get a ADC chip with enough inputs. Although it would be best to get some sort of uC to read the analog signals and send them through serial stream on a single chip, less wiring less things to go wrong. Also make sure to have enough inputs, as I said before, cause you don't want to have to wire voltage follower circuits and make the uC switch between them.
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MikeMurphy
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nismofan14
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huguetpj wrote:It definetly ain't that hard. The tricky part is the interface between the analog volt signal and the laptop. How is it you are going to do this? You mention you will be building a unit, I'm guessing using some kind of uP to convert the analog signals into a data stream through USB or serial as you also stated. There are some very good uPs out there with 4-16 analog inputs.
You just need to have the software read the serial port periodically, maybe send a signal to the uP to start streaming, read the data and display it.
One other question, thing you might wanna consider. What software is ur friend using if we can know? Cause the few softwares I've played with don't have very good displaying objects (meters, clocks, graphs) so if he can get some good controls for displaying that would be best. Specially for the knock meter since the signal is just garbble unless you filter it or display it on a time graph.
I found the chips on the net ADuC812 , ADC , but the problem I am having is that, do I need one ADuC812 for each sensor , or can I just do one ADuC812 for multi (let's say 5)sensors , plus? are those sensor instant , not any delay at all?if that's the case , can I put a clock unit and some memory , then it takes turn to send the singal to the ADC , if the chip is effiecent enought and it can be done the job within a sec to send all the sensor singal, I think one is good enought..what do u think
by the way ,there are so many aftermarket unit out there ...but It's a DIY project ... so...
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nismofan14
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nismofan14
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Hope it works out for ya.nismo1003 wrote:I found the chips on the net ADuC812 , ADC , but the problem I am having is that, do I need one ADuC812 for each sensor , or can I just do one ADuC812 for multi (let's say 5)sensors , plus? are those sensor instant , not any delay at all?if that's the case , can I put a clock unit and some memory , then it takes turn to send the singal to the ADC , if the chip is effiecent enought and it can be done the job within a sec to send all the sensor singal, I think one is good enought..what do u think
The AduC812 is discontinued (if you were planning on buying one new) so you might wanna look at the ADuC814 which they reccomend as a substitute. Anyway, both of them work on 3V or 5V so you would need to wire in a regulator and you couldn't measure anything above 5V. They do have 8 chan/6 chan, respectively, so you could measure 8 or 6 signals at the same time. A 5us refresh time is quite enough for real time display of any automotive parameter.
But you still need to convert this to serial stream in which case you would need one more IC.
My suggestion get one of these or similar: 68HC05B6 More here
This seems interesting 8-bit ADCMore single ADCs
But I'm having trouble finding any ADCs that work at 12V. Is there any signal you would want to measure that is above 5V?
nismo1003 wrote:huguetpj what kind of knock sensor I should use for that ADC chips.... can I use the stock one or I shoudl have a extra one just for the chips? all I want is to monitor the knock ( knock alert and meter bscially)
Use the stock one. You can lower the refresh time (using software) to filter the signal in essence and make the wave look smoother in order to have a usable alert.