Matrix user forums

BEST 18F4455 USERS

I have successfully builded my program with lcd via e blocks. Now I want to build a small print for it but i first want to try it out on a breadboard.
I have put all the components correctly on the breadboard....like the oscillator crystal of 4Mc with the 2 caps of 27 pf ....and i have soldered a new 9pins connector
on my e block lcd to see if my builded program is working on a 'print'. But unfortunately the 18F4455 is doing nothing. By spending already hours by reading the datasheets
and trial and error methods and reprogramming the configuration bits it is still not working on a breadboard .....does somebody know what the difference is between the
circuit on an e block and on a breadboard.... is the xt xt usb configuration not responsible for it ??? and how can i only select xt pll on an 18f4455 ???? does someone know
what i do wrong???

thanks
puts johan
engineer electronics belgium

Hello PUTS_JO.
Is pin 1 connected to anything?
MCLR can be used for reset, but to do that it must be connected via a pull-up resistor.
If pin 1 is not connected to anything then go into the configuration menu ('Chip Configure..') click on 'Switch To Expert Config Screen' and if enabled change Master Clear Enable to MCLR Disabled'
Have you tried toggling a pin 1 Hz, and checking if changing every second ?
You don't have to have the osc set to 48MHz, E.g can set osc to 4MHz
Failing that post a circuit diagram and flowchart and can take it from there.

Hi PUTS_JO,

One thing I've experienced with bread board is that it suffers from parasitic capacitance. This could be stopping the crystal from going into oscillation. Hence stopping your circuit from functioning.

Regards

JAW

Thanks JAW, that reminded me. I had an issue with chip kept on resetting, A 100nF cap across VDD and VSS solved that.

EUREKA MEDELEC 35 AND JAW,

BY LOOKING PRECISELY TO THE PIN NUMBERS I DID A STUPID THING ; FOR TESTING I BOUGHT A NEW 9PIN CONNECTOR, SOLDERED WIRES ON IT
AND PLUGGED IT IN THE LCD E BLOCK ... AND PUTTED THE WIRES IN THE BREADBOARD ON THE PINNING OF PORT D.
WHAT HAPPENED... THE PINNING IS COUNTING UP 19=RD0; 20=RD1; 21=RD2 ;22=RD3; 23=NOT RD4 BUT RC4.....STUPID ...STUPID....STUPID
RD4=PIN 27 SO THANKS FOR YOUR HELP :EVERYTHING IS WORKING PERFECT NOW.

Man i want to try this clock program that i wrote for my ECT class on the breadboard it uses 3 switch and and 2x16 LCD. it displays min sec and hour, and can be changes accordingly