Michael Amling

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11 years, 1 month ago.

Analog In, Output @ PC

Hello,

can someone help me? I need a program that reads the voltage at the analog input and output of a terminal program on the PC as analog and digital output. Is that possible?

Thanks in advance

3 Answers

Martin Smith
11 years, 1 month ago.

Are you after something like this?

#include "mbed.h"

AnalogIn ain(p19);
Serial pc(USBTX,USBRX);

int main() {
    while(1) {
        pc.printf("\r ain = %f V   ",ain.read()*3.3);
    }
}

Accepted Answer

Yes, I am!

posted by Michael Amling 09 Apr 2013

Hello, can someone help me? I need a program that send the 20v voltage from mbed analog output pin 18 to a device. also, I can read that on a tear terminal program on the PC. Is that possible? thank you

posted by sasa sasa 09 Feb 2016
David Golz
11 years, 1 month ago.

Hi Michael,

If you are new to mbed, I am recommending the getting starting guides! Choose the right one for your board: LPC1768 or LPC11U24 or FRDM-KL25Z. After that, this should help you: /handbook/AnalogIn

Michael Amling
poster
11 years, 1 month ago.

Hello David,

thx for your fast answer. you're right i'm new with mbed and i read a lot about it.

I am a student and working in a project. I need to read from a rear wheel travel sensor (-3V to +3 V) voltage and provide it to a CAN message. I know that the mbed controller can not have negative voltages at the analog input. This is prevented with a prescreening.

I can do that the voltage at the analog input could be read and send to the serial port. (multiplier 3.3). Unfortunately, I do not know now how I can proceed in the program code to provide these analog signals for the CAN bus. Can you help me maybe?

Sorry I hadn't worked with CAN so far. You may already found this one: /handbook/CAN. The mbed can't also handle negative voltages at any other pins. So it's really important to secure your mbed. Am I right you throw the negative voltages away? Did you think about an operational amplifier? An inverting op-amp with an absolute gain < 1 and summing a positive voltage, so the range will be inside 0V to 3.3V.

posted by David Golz 09 Apr 2013