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This project is a fully designed bespoke digital boost gauge for use in high pressure turbocharged applications.
There are gauges out there with 1 Bar maximum range and 10 LEDs, but these lack resolution and cannot cope with the pressure requirements of a chipped petrol engine or a high performance diesel.
My car produces typically a peak pressure of 1.4 Bar G at the intake manifold.
My design will incorporate a Motorola MPX4250ap pressure transducer (capable of 0.2 Bar to 2.5 Bar absolute or -0.8 Bar to 1.5 Bar gauge)
The sensor is specially imported from the USA, as UK based supplies are apparently nonexistent.
At the heart of the design is the pressure sensor, supplied with a regulated 5V source.
The processing of the signal is simple and the representation will take the form of a 20-LED bargraph.
The old-skool favourite LM3914 IC holds the key to the LED driver system.
Two chips in cascade arrangement, allowing zero at the first LED and perhaps 1.4 Bar (settable) at the farthest end.
Here's where it all starts......the prototype.
Not much to look at but it's working 100% correctly on the breadboard.
The led bargraph displays are just for test purposes (i have 20x of these so just holler if you want one for £1 each!)
I am now designing the PCB, which will carry all the main components.
Not sure about where to locate the pressure sensor......it's possible to place under the bonnet in an IP rated box perhaps.
Am now also working on the LED arrangement - I have white and blue 3mm leds arriving from Hong Kong next week, so you can already get a flavour for the theme!?
There are gauges out there with 1 Bar maximum range and 10 LEDs, but these lack resolution and cannot cope with the pressure requirements of a chipped petrol engine or a high performance diesel.
My car produces typically a peak pressure of 1.4 Bar G at the intake manifold.
My design will incorporate a Motorola MPX4250ap pressure transducer (capable of 0.2 Bar to 2.5 Bar absolute or -0.8 Bar to 1.5 Bar gauge)
The sensor is specially imported from the USA, as UK based supplies are apparently nonexistent.
At the heart of the design is the pressure sensor, supplied with a regulated 5V source.
The processing of the signal is simple and the representation will take the form of a 20-LED bargraph.
The old-skool favourite LM3914 IC holds the key to the LED driver system.
Two chips in cascade arrangement, allowing zero at the first LED and perhaps 1.4 Bar (settable) at the farthest end.
Here's where it all starts......the prototype.
Not much to look at but it's working 100% correctly on the breadboard.

The led bargraph displays are just for test purposes (i have 20x of these so just holler if you want one for £1 each!)
I am now designing the PCB, which will carry all the main components.
Not sure about where to locate the pressure sensor......it's possible to place under the bonnet in an IP rated box perhaps.
Am now also working on the LED arrangement - I have white and blue 3mm leds arriving from Hong Kong next week, so you can already get a flavour for the theme!?