For the brake pressure, you need a load cell to convert pedal pressure to a
voltage, as attempts at using pedal position as a measure of braking
pressure is subject to too many indeterminate variables.

The same principal is applied on race bikes for their so called 'quick
shifters' which detect gear pedal pressure and apply an engine cut pulse to
unload the gearbox, permitting rapid shifting up without clutching or
'blipping' the throttle manualy.

For such a cell, try Sparkfun Electronics (>$10)

On Mon, Sep 3, 2012 at 9:26 PM, Nily <seoane_re@sinectis.com.ar> wrote:

> with a lathe, you can easily make your own flow meter, for a few $, i.e.
> aluminium block, bar, hall sensor,etc or teflon....
> http://www.youtube.com/watch?v=3D9VruZyVyjqA&feature=3Dplayer_embedded
>
> Is brake pressure important to measure ?. Or you need brake on and off.
>
> Rodolfo
>
> -----Mensaje original-----
> De: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu]En nombre de
> Bob Blick
> Enviado el: Lunes, 03 de Septiembre de 2012 09:37 a.m.
> Para: Microcontroller discussion list - Public.
> Asunto: Re: [EE] Fuel and pressure sensors
>
>
> Hi David,
>
> I've played around with this a bit on automobiles. On racing cars,
> getting accurate measurements is worth it. Plus you have support staff
> to take care of the data. But in the amateur world that I'm in, it's too
> expensive and time-consuming. Brake fluid on cars is 1500 PSI. Just
> buying a T-fitting with the proper adapters costs $$.
>
> I switched to using string pots to measure throttle position and brake
> pedal position. You can get very useful data. So what if it's not
> absolute?
>
> Making string pots is easy if you are handy with tin snips and glue.
> I've planned to sometime put together a web page. Haven't done it yet
> but do have all the photos I took. If you are interested I can send some
> to you.
>
> Another shortcut I recommend is to put the throttle and brake data on
> LED bargraphs within the view of an in-car video camera. It makes
> reviewing the data a little less tiresome.
>
> Best regards,
>
> Bob
>
>
>
> On Mon, Sep 3, 2012, at 08:29 AM, David wrote:
> > Hi,
> >
> > I'd like to measure a few things from a small go-kart, namely the fuel
> > flow rate (petrol) and the brake pedal (hydraulic).  My primary
> > requirements are:
> >
> > - interface to a standard PIC uC
> > - cumulative total of fuel used
> > - a few readings per second for hydraulic pressure (between 'pedal
> > unpressed' and 'pedal fully depressed'), if possible
> > - inexpensive, this is for a charity and I don't want to be spending
> > =A3=A3=A3 on sensors
> >
> > Suggestions for sensor manufacturers to look into would be great.
>
>
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