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Voltmeter

farouk_ch10
Associate II
Posted on January 31, 2014 at 21:34

Hello

I want to make a voltmeter using my STM32F4  discovery , actually these are my first steps and I am facing some problems and I need some help.

Thank you very much.

#lmgtfy
28 REPLIES 28
Posted on February 11, 2014 at 16:44

Jumper the VDD and BOOT0 pins, restart the board, attach via ST-LINK Utilities, Connect and Erase part.

0690X0000060MnxQAE.gif

http://www.st.com/web/en/catalog/tools/PF258168

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farouk_ch10
Associate II
Posted on February 11, 2014 at 17:33

Thank you very much clive1 , it works!

the problem is solved .

farouk_ch10
Associate II
Posted on February 11, 2014 at 21:28

Hello,

I want to make an Ammeter using my stm32f4 , any ideas please.

(I prefer not to use the shunt)
Andrew Neil
Evangelist III
Posted on February 11, 2014 at 21:42

http://www.lmgtfy.com?q=current+sensor

chen
Associate II
Posted on February 12, 2014 at 10:56

''

http://www.lmgtfy.com?q=current+sensor

''

Now that is just mean and UNHELPFUL.

''I want to make an Ammeter using my stm32f4 , any ideas please.

(I prefer not to use the shunt)''

A shunt is easier and not that bad - most multimeters use the shunt meathod.

OK - what is a shunt - just a resistor! The Shunt resistor is placed 'in line' with the power source. So all the current to the circuit flows through the shunt resistor.

Volt = Amp X Ohm

therefore

Amps = Volts / Ohms

If you use a 1Ohm shunt resistor - the current is simply the Volts measured across the shunt resistor.

If you do NOT want to use a shunt - then look at the current clamp devices (it is just a special, calibrated Hall effect sensor in a ferrite core) that are available. They will have data sheets.

frankmeyer9
Associate II
Posted on February 12, 2014 at 11:29

''

http://www.lmgtfy.com/?q=current+sensor

''

 

Now that is just mean and UNHELPFUL.

 

I don't think so.

If someone likes to deal with such complex matters as Cortex-M MCUs, and carries 'student' as part of his nickname, it's only fair to expect a certain amount of individual initiative.

If the OP neither knows any concept of measuring electrical currents, nor is able to look up such things himself, he'd better return to some more basic projects.

farouk_ch10
Associate II
Posted on February 12, 2014 at 17:20

Thank you for your response.

farouk_ch10
Associate II
Posted on February 12, 2014 at 17:24

Thank you for your response.

frankmeyer9
Associate II
Posted on February 12, 2014 at 19:36

No offense intended.

Neil's posts are often quite outspoken, but nonetheless true.

Andrew Neil
Evangelist III
Posted on February 12, 2014 at 20:03

''

I prefer not to use the shunt''

Why?

What specific objection(s) do you have to using a shunt?

If you don't state the reason(s), how can people avoid making suggestions which might suffer from the same - or worse - problems...?!