Search found 25 matches

Actually the 'data sheet' has _nothing_ to do with the capacitor values that should be used, unless you are using exactly the crystal models recommended by Microchip....
The _crystal_ will have a spe ...

I am using 22pF for 4MHz and I did not change them for 20MHz. Do I need to ?

Check the data sheet first! And then try if the values given by the data sheet work with you project or not - if not -yo ...

I am using 22pF for 4MHz and I did not change them for 20MHz. Do I need to ?

Er. That will stop the chip running. MCLR needs to be pulled _up_, not to GND.

Best Wishes

Yes, my mistake - you are right. The resistor to the power line (eg 5V) and not to GND.

so, i just n ...

OK. Good.
Now, have you tested that this is working correctly?.
There was a several entry thread only a few days ago, where one pin of the MAX232, was not correctly connected, and the poster was hav ...

Q2: which cellphone do you use? Did you check the cell-phone serial communication parameters/protocol, esp the electrical levels of the comm-lines and the hand-shake protocols?

the Cell phone is T6 ...

Next to a possible GND-problem you may not have put a 0.1µF capacitor between Vdd and Vss or the MCLR-pin is not connected/set properly.

the MCLR-pin connected correctly i test it But i did not pu ...

So you are able to connect the phone to a PC directly?.
So, how are you connecting to the PIC?. You are aware that you _need_ an inverting RS232 buffer between the PIC and the phone, if the phone can ...

Q2: which cellphone do you use? Did you check the cell-phone serial communication parameters/protocol, esp the electrical levels of the comm-lines and the hand-shake protocols?

the Cell phone is T6 ...

Next to a possible GND-problem you may not have put a 0.1µF capacitor between Vdd and Vss or the MCLR-pin is not connected/set properly.

the MCLR-pin connected correctly i test it But i did not pu ...

If the circuit behavior changes when you touch it, the first place I would look is for a bad GROUND connection.

But I checked the circuit on the board on another pic with different code that also u ...

Q1:
I programed my pic16f877a to send a serial data (information about my project ) to my PC but the Hyper terminal receives unknown symbols -infinitely - and when I touch it it changes the symbols.( ...

I am using pic16f877a microcontroller to send and receive text messages but my cellphone (T68i sony ericsson) do not support Text mode so I need to convert the message I receive to Text and I write t ...

I don't have Proteus and don't want it. I think that very few people on
here want to trouble-shoot problems that may involve Proteus bugs.
We want to solve coding bugs and CCS bugs, and some ha ...

I am using Proteus simulator to connect the pic and the cellphone. I am using three hyperterminal two to see the output from the pic and input to pic{from cellphone} and one act as PC(hyp). When I use ...