HI!!
I declared 3 global var, i call it inside diferent task and every execution this var should be updates but not to do it. I have a 8051 under evaluation board. Maybe can be a problem of my small micro? What do u think about this?
Thanks
Maybe can be a problem of my small micro?
Most likely not. I would guess it is a problem with the code, but lacking the code it is hard to verify that.
What do u think about this?
I think that given the scarcity of information, any statement about the nature of the problem can be classified as speculation.
What do u think about this? I have no idea what micro (u) think about this, what I think is that you are trying to run before you have even learned to crawl, that is a surefire way of breaking a leg. learn to crawl, THEN learn to walk, THEN learn to run. 1) read "the bible" and the datasheet for your device a couple of times to familiarize yourself with the contents. 2) work through (I did NOT say 'read') the Keil "getting started guide" 3) do some simple projects (start with 'blinky') gradually adding complexity 4) go back to whatever running it is you are trying to do way too early.
Erik
Thanks for your reply. But i think that the problem is not the implementation because is a simple acumulate. I dont understand why this var not acumulate the old value.
The var values in my debugging are 10, 4 ,... im trying change the data type for unisgned int and is the same.
Let me give you simple example with signed int (-32768 to +32767). In mathematical notation:
SP=3000 (setpint) PV=0 (value read from ADC) Kp=12 P=KP*(SP-PV)=12*(3000-0)=36000
This causes an overflow. The result is treated as a negative number.
I understand your example. But in my code i have this:
First iteraction SP=10 (setpint) PV=0 (value read from ADC) Kp=1 P=KP*(SP-PV)=1*(10-0)=10 Second iteraction SP=10 (setpint) PV=6 (value read from ADC) Kp=1 P=KP*(SP-PV)=1*(10-6)=4 but my pid->iState should be 10+4=14, and it is 4
i dont know why dont save the old value in pid->iState
Are There Anybody that help me with my project?? Maybe i can send the code for see it!!!
It is very important for me!! Thanks
You've checked only this part of your code? You have to ensure, that there is no underflow/overflow/division by 0 in the whole code and under all circumstances (for example extreme user input). The "updating problem": It helps a lot if you screw down your code to the interesting core and debug it. If this fails you can show this very short program and all the necessary information to the forum. And don't forget to mention the controller, hardware, RTX. Check the datasheet of the controller and the camera. It seems you didn't.
Sorry. "Camera" belongs to an other thread I read in parallel.
OK! Im working with an emulator (EPM900) and an evaluation board (MCB900), my micro is Philips P89LPC936, under RTX-51.
Independent of my PID, the problem is the var update. For example:
void Write (void) _task_ WRITE _priority_ 1 { int Ub=0; while (1){ Ub+=1; TXRX_putByte(Ub); //send to serial port } void main (void){ os_start_system (WRITE); }
The var Ub always is 1, never update the value ???????
Recently i debugg my code in the simulator of uvision and all var are updated!!! Why dont work in my board?????????
Recently i debugg my code in the simulator of uvision and all var are updated!!! Why dont work in my board????????? DUH, the simulator simulates.
if there is e.g. a baudrate error, the simulating thing will still work, if the internal XRAM in the device is not enabled the simulating thing will still work, ....
if the var you are hunting is in xdata, I'll bet you dollars to doughnuts that you have not modified startup.a51 to enable your XDATA.
BTW this newfangled thing that only few know about called a datasheet will tell you what is needed.
looking at the Keil manual and the startup code will show you why this must be at the start of startup.a51.
java
you be please ignoring sir eracs terrrible sarcasem.
he is be thinking he be funny,,, but he is just crazy yes.
rahib, what happened? where is praise? where is the submission :) :) :) where is the propaganda ?! it is sir erac you are talking about maaaaaaan !!!!
now seriously: your friend did not provide vital data that could have solved his problem earlier and save us time, headache and heartache! instead he offered money. YUK.
HI Eric!! First thanks for your reply.
My code startup is: START900.A51 because i use Philips P89LPC936. It has 512 bytes of xdata.
I have modificated only this:
; <o> XDATASTART: XDATA memory start address <0x0-0xFFFF> ; the absolute start-address of XDATA memory XDATASTART EQU 0x000 ; ; <o> XDATALEN: XDATA memory length <0x0-0xFFFF> ; the length of XDATA memory in bytes. XDATALEN EQU 0x200 ;
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