Reading ADC Values

[Dermot Donnelly]

Hi. I need a little help to get started. I have used the picaxe but want to migrate to GC Basic. I'm a bit confused with how the pins are designated especially with regard to reading an analogue value from a pin.
Perhaps I can make clearer my problem if I show the picaxe code I want to convert to GCBasic:

'picaxe 14M2

readadc C.4,b0 'reads the value on pin C.4 (leg 3 of 14M2 which is 16F684) and stores it in variable b0

pause 50

    if b0>=120 then goto State0001   'if it is above a certain value then the code brings us to somewhere else in the program but I don't know where to store the value to put in the if statement

In GCBasic I think it should be something like:

ReadAD(A????

but I don't know what to call the ADC pin.
Any help would be much appreciated. I have looked at the examples section but unfortunately the only relevant example I came across was something requiring a chinino library?
regards
Dermot

[stan cartwright]

hi
portc.4 is not an a-to-d pin. port c.3 is and it's called an7
14m2 is pic 16f1825...see data sheet..page 4 http://ww1.microchip.com/downloads/en/DeviceDoc/40001440E.pdf

dim adcval as byte ;variable to store adc
dir port c.3 in ;make port input
adcval=readad (an7) ;read adc and store in adcval

[Dermot Donnelly]

Thanks very much for that stan. That was exactly the information I was looking for.

[William Roth]

Hi Dermot,

Welcome to GreatCow BASIC

With PICAXE, you probably never had to look at a PIC Datasheet. With Great Cow BASIC you will need to look at a PIC Datasheet from time to time.

Each PIC Datasheet has a PIN section and a Table where the pins and their related uses are shown. This is usually Table 1 and is found in the first few pages of the Datasheet, Attached is Table 1 for a PIC 16F1825 which is the PIC equivalent of Picaxe 14M2.

In the first column it shows the PORT/ PIN and in the 4th colum it show the ADC channel designator. Example RC2 - AN6

You may want to print this chart out when using a PIC for the first time. I have a folder full of them for varius devices.

[Dermot Donnelly]

Thanks very much for that William. Looks like I'll have to RTFM from now on! I found the data sheets a bit daunting but you've cleared away some of the fog. Thanks again.