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Seven Segment Gear Indicator

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matt_hau

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I am trying to find a circuit for a seven segment display driven by varying dc voltage from a motorcycle gear position sensor.

It needs to be very compact as is the GIpro gear indicator oon the market. By all accounts it seems that the brains of the display driver is no bigger than the display itself.

Anyone know how this is done?
 

matt_hau

New Member
Seven segment Display

Would a 7447 7 segment display decoder work? If so how would I turn the voltage from the bike to binary code?
 
i used a 4511 as a seven segment driver and it is cool....checkout its datasheet at alldatasheets and it is just a 18 pin DIP stuff....try it out
 

matt_hau

New Member
Thanks I have seen the 4511 decoder but from what I understand about it I still need to convert the analog signal from the motorbike into a binary code??
 

Brian Hoskins

New Member
matt_hau said:
Thanks I have seen the 4511 decoder but from what I understand about it I still need to convert the analog signal from the motorbike into a binary code??
That's what an ADC is for. You'll need to do some homework if you expect to be able to use one though. They're not that difficult really, but you need to understand what you're doing with them. Also you'll probably need to do some signal conditioning such that your analog output fits within the "window" of the ADC input.

Brian
 

matt_hau

New Member
Brian Hoskins said:
That's what an ADC is for. You'll need to do some homework if you expect to be able to use one though. They're not that difficult really, but you need to understand what you're doing with them. Also you'll probably need to do some signal conditioning such that your analog output fits within the "window" of the ADC input.

Brian
The range of volts is 1-5DC. Can you suggest a link that will show me "signal conditioning" ? I have been searching everywhere and although I can find lots of technical talk on ADC there is nothing in laymens terms or a basic explanation of how to generate the required binary output (that I can understand anyway).

e.g. how do you create the required binary from the ADC to meet the seven segment decoder requirements? is it software or simply input voltage?
 

Brian Hoskins

New Member
matt_hau said:
The range of volts is 1-5DC. Can you suggest a link that will show me "signal conditioning" ?
Signal conditioning is fairly simple - you just use Op-Amps. Gain can be used to make the signal bigger if it's too small or smaller if it's too big. Then addition / subtraction can be used to "shift" the signal up or down (alter it's D.C. level) such that it fits as tightly as possible into the window of the ADC. Are you familiar with the use of Op-Amps? Do a bit of research and see what you can find out. If you're still stuck, come back and I'll post some example circuits that you can alter to suit your requirements.

matt_hau said:
e.g. how do you create the required binary from the ADC to meet the seven segment decoder requirements? is it software or simply input voltage?
7-Seg displays work on BCD. The output from the ADC will be binary - therefore you need a Binary to BCD converter like this one for example:

http://www.electro-tech-online.com/custompdfs/2008/01/DM74185.pdf

Brian
 

7138

New Member
?

hi had the same idea for my college project but using the current from the coil to convert into binary is too complex i thought of using infrared sensors and making my circuit simple and then using pic axe to write a program do u kno were to get a circuit diagram of the project????
 

blueroomelectronics

Well-Known Member
hi had the same idea for my college project but using the current from the coil to convert into binary is too complex i thought of using infrared sensors and making my circuit simple and then using pic axe to write a program do u kno were to get a circuit diagram of the project????
Custom designs will require custom schematics.
 
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