Issues with reading an analogue voltage signal

[Aidan_OSullivan]

We have been attempting to a read an anlogue input from a power supply to our BL0011 board. We are using the analogue pin E0. When we try to display this on our LCD screen it is coming up as either active low or active high depending on the input voltage. We would like to display the voltage as an analogue reading.
We were trying to figure out how to configure the internal ADC but were unable to do so from the program. As an alternative we tried using C code to store this voltage value using analogRead, as seen below:
FCV_Voltage = analogRead(E,0);
We were given the following errors- 9643: FCV_Voltage = analogRead(E,0);
^ (192) undefined identifier "FCV_Voltage"
^ (361) function declared implicit int (warning)
^ (192) undefined identifier "E"
Should this C code method work or is there another alternative using the internal ADC? Any assistance with this would be greatly appreciated!

[medelec35]

Hi Aidan,
It would help if you can post the flowchart that's got the issues you describe.

[Aidan_OSullivan]

Mi Martin, I have attached the file using C code to read the analogue signal.
If that method isn't possible I am wondering if there is any way to use a component macro such as the 'IO_ReadAnalogasByte' that is available to read the analogue signal from either the LDR or POT that could read the analogue signal from the external power supply?

[Benj]

Hello,

This should help. I've added an ADC input from the Inputs component category and connected it to pin E2 via the component properties.

AnalogueMeasurement.fcfx

(15.83 KiB) Downloaded 206 times

[Aidan_OSullivan]

We have now successfully managed to read an analogue signal from the power supply. We are then routing this from the ADC to the DAC in our SPI master board (EB013). The output from the DAC is coming out as approximately half of our input voltage. The output of the DAC is an open circuit so no divider network is being created. Is there any way of creating close to a 1:1 input to output in the DAC?

[Benj]

Hello,

The difference could maybe be down to a different bit depth between the adc input and the DAC output.

What about doubling the digitised adc reading?

output = adc * 2

or more efficient but does the same thing.

output = adc << 1