simple ADC program for PIC16F88 somehow gone wrong!

Status
Not open for further replies.
S

Steve311

Member
Hello All; I am trying to make a very simple ADC program with a PIC16F88 which reads only one input at AN4. The PIC has a 10bit output which I want to be shown on pins RB0-RB7, RA0 and RA1 by just sending a logic 1 or 0 to each pin. I am using MPLAB IDE and MPLAB SIM as the compilier. I notice there is an error which says ADC-W0008: No stimulus file attached to ADRESL for A/D. which I don't understand. I know the code is very close to what it needs to be but I am missing something subtle....Any suggestions or comments would be GREATLY appreciated here! Thanks in Advance....

And also, what would be the best way to test this? Im currently using a pot to vary a dc voltage at the input AN4 with a range between vdd and vss....will this suffice?

Attached is my .asm file
 

Attachments

  • A_D Conversion Code.asm
    4.2 KB · Views: 311
Check my tutorials, which take you through how to use the analogue inputs.

A simple pot is fine for a test, but it really needs to be a fairly low value, 5K or lower.
 
Last edited:
hi Steve,
Your program runs OK in the Oshonsoft simulator.
 

Attachments

  • AAesp01.gif
    16.1 KB · Views: 325
Thanks Eric; That makes me fuul much better....

I changed the code so the output is only a 8bit resolution, and I would like to send these values to RB0-RB7 respectively and have them be held high or low so I can read the output with a voltmeter at the pins....Do you see any issue with how I am sending these values to PORTB so i can read them? Thanks again!

Steve
 

hi Steve,
If you post your latest code I will give it a run in the Sim.
 
Hi Eric; Thanks again i really appreciate it. Attached is my latest version. And again, my goal is to read the outputs on PORTB respectively.

Steve
 

Attachments

  • A_DConversionCode_asm.zip
    2 KB · Views: 212
Steve311 said:
Hi Eric; Thanks again i really appreciate it. Attached is my latest version. And again, my goal is to read the outputs on PORTB respectively.

Steve
Click to expand...

Downloaded it, ok

EDIT:
Required editing, this now works.
Remember for 8 bit operation, its left justified and in ADRESH
 

Attachments

  • A_D Conversion Code.asm
    3.9 KB · Views: 291
  • AAesp02.gif
    44.6 KB · Views: 314
Last edited:
Hi Eric; Thank you very much for editing my code. I see everything working as planned now. I understand the changes you made and I see where I was going wrong. Knowledge is power!

Thanks Again!
 
Hi Eric, i am using the same PIC16f88 using RA0 as my input and RB0 as my output, then pin 5 and pin 14 for my power supply (+5v and -5v), then i am going to transmit it wirelessly, i have the code for the transmitter but i am really stuck on the A to D conversion.. please help.. many thanks!
 
Steve311 said:
...which says ADC-W0008: No stimulus file attached to ADRESL
Click to expand...

When you are testing your program in MPLAB SIM, you can choose to simulate voltages on the A/D inputs to test your program properly.

These are called stimulus files. If you get that error that means there is no stimulus file. It's not a program error as such, but it's just letting you know that your A/D input will stay at 0v in the simulator and therefore can't be simulated properly.

I hope that made sense.
 
And i am measuring 0-5 voltage for my input then transmit it wirelessly, i only need an ADC code for my pic.. im really stuck..
 
Status
Not open for further replies.

Similar threads

@
  • Question
BluePill ADC not working
Replies
2
Views
982
rjenkinsgb
E
  • Question
C Program Memory Layout in Embedded Systems
Replies
5
Views
803
ahsrabrifat
A
S
  • Question
Choosing the Right Protection for Digital and ADC Inputs
Replies
5
Views
6K
danadak
P
  • Question
PIC KIT 3 not able to program dsPIC
Replies
8
Views
398
Nigel Goodwin
X
  • Question
Battery consumption for MCU
Replies
9
Views
1K
schmitt trigger
S
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…