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need help urgently!!!

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nistelrooy

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okay i'm building a fan speed controller using the pic 16f84a.

I have two inputs: i)infrared sensors to count the number of people (4)
ii) a temperature sensor

and one output: i) fan speed control

Okay i desperately need a circuit for the temperature sensor.

i'm using port b as the input...so i'm having problems with pin assignments.

if i use a lm35dz, i have to interface it with an adc 0804, so will i have enough pins (4) for my infrared input??

Please suggest the alternatives
 
well the thing is i'm running short of time, and i already have a programmer for the pic 16f84a.

so please suggest alternatives for temp sensing.
 
if you want it quick you can get a dallas ds18S20 or one of those, simple to interface, direct to digital temperature.
 
samcheetah said:
well the thing is i'm running short of time, and i already have a programmer for the pic 16f84a.

cant that programmer program the 16F819, 16F628 and the like????

Depends on the programmer, the hardware interface of the chips is identical, it's only the software which is different - if it's a really obscure programmer, that requires it's own specific software, it might not have been updated. But any standard parallel port programmer can use either WinPicProg or ICProg to program the 16F819.
 
samcheetah said:
well the thing is i'm running short of time, and i already have a programmer for the pic 16f84a.

cant that programmer program the 16F819, 16F628 and the like????

The JDM programmer powers the PIC when it is not being programmed, thus if a flashable PIC has a program it will start running before the programming can begin. Depending on how the program configures the IO pins it can make it impossible for the JDM to reprogram it.

There are modifications to the JDM programmer to correct this, or you can use a different design, like the **broken link removed**.

I ran into this issue when migrating from the F84 to the F628 so I had to change programmers.

Dan East
 
Dan if u had been using a programmer based on the P16PRO40 hardware (like Ozipic'er) u wouldnt have to do that.

hey ive seen a little about the '819. it has great features and its better than the '628. twice the memory and twice the speed of the internal oscillator. and plus a PWM module.

Nigel i heard u once saying that u have made a voltmeter based on the '819. what else have u made with it?

i think that the '819 can be used with all your tutorials. am i right??? if yes then are u going to add a page for the '819???
 
samcheetah said:
Nigel i heard u once saying that u have made a voltmeter based on the '819. what else have u made with it?

i think that the '819 can be used with all your tutorials. am i right??? if yes then are u going to add a page for the '819???

So far I've only played with the 819 a little bit, I've been using it for a two channel digital voltmeter using an LCD text display. Basically using the routines from the tutorials with slight modifications.

As you say, the 16F819 could be used to replace the 16F628 in the tutorials, it's just a question of altering the setup code slightly. I may add some tutorials based on the 16F819, or I may just add a page explaining how to do it yourself - like I did with the 16F876/7.

It's all a question of time :(
 
Dan East said:
The JDM programmer powers the PIC when it is not being programmed, thus if a flashable PIC has a program it will start running before the programming can begin. Depending on how the program configures the IO pins it can make it impossible for the JDM to reprogram it.

There are modifications to the JDM programmer to correct this, or you can use a different design, like the **broken link removed**.

I ran into this issue when migrating from the F84 to the F628 so I had to change programmers.

Dan East

Well thats why they have 13v input for the MCLR so it's in programming mode a soon as the 13v is on.
 
pike said:
Dan East said:
The JDM programmer powers the PIC when it is not being programmed, thus if a flashable PIC has a program it will start running before the programming can begin. Depending on how the program configures the IO pins it can make it impossible for the JDM to reprogram it.

There are modifications to the JDM programmer to correct this, or you can use a different design, like the **broken link removed**.

I ran into this issue when migrating from the F84 to the F628 so I had to change programmers.

Dan East

Well thats why they have 13v input for the MCLR so it's in programming mode a soon as the 13v is on.

if you apply power before MCLR (what JDM does). then the pic will start running its program (if it is on internal osc.) in wich case it cannot be switched to programming mode.
 
Programmer, I posted my PG2C on this forum, you can download it from my signature. However, I recommend you to use Nigel programmer. Both, you may use ICPROG free download.

The problem is not only how to read the ADC of temperature sensors. It's easily done with Nigel's tutorial. But the problem is your control rules. What is your control rules? You cannot use it with linear control, because the fan speed has only some levels and the indoor temperature is never changed so fast as your uC instructions. It needs quite long time to change, and the temperature feedback will never be really "real time". As you accelerate your fan, it need a range of time for the temperature change, and you will see that, when the same number of people stay long time in a room, the temperature will be higher, but it takes time. In that time, people will feel so hot, because the late respond of sensors!

I hope you solved this problem theorily.
 
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