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LDmicro Forum - 16f84

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16f84 (by manrique gonzalez)
como puedo utilizar esto con los pic 16f84
gracias aprecio su valioso tiempo
gracias.
Sat Jul 11 2009, 15:32:26
(no subject) (by Jonathan Westhues)
The PIC16F84 has been obsolete for many years. You can get a pin-compatible replacement (e.g., the PIC16F628A) with more RAM and flash for less money.

The 'F84 also doesn't have a Timer1, which LDmicro uses to calculate the cycle time. So it would be difficult to add that target to LDmicro in any case.
Sat Jul 11 2009, 16:37:52
message display (by amjad)
hi, sir
i am new in pic microcontroller i dont understand its
programming,but i understand ladderwork and i perfectly use
differet type of ladderwork software justlike omeron plc ladderworke.
sir, i want use message display with two input npn sensors and two output relays and its instruction show me on a dispay,please can you tell me on ladderlogic how its done it.
Fri Oct 30 2009, 00:47:10
(no subject) (by Jonathan Westhues)
Have you looked at the tutorial, at

http://cq.cx/ladder-tutorial.pl ,

or the microcontroller interfacing tutorial at

http://cq.cx/interface.pl ?

A sensor with an NPN output can be wired directly to an I/O pin on the microcontroller, with a pullup resistor, and possibly with some series resistance to help protect the pin against damage. For example, you might wire from the sensor output to Rpullup ~ 10k, and from the other end of the pullup resistor to 5 V. Then you would wire from the sensor output to the I/O pin, through Rseries ~ 10k.

Rseries isn't really necessary; you could wire directly from the sensor to the pin. But if there is an ESD (static electricity) event, or if a high voltage accidentally gets applied to that pin, then the resistor limits the fault current and increases the odds that the micro will survive. But as that series resistor--and the pullup resistor--get bigger, the noise immunity decreases, so it's a tradeoff. A few nanofarads from the I/O pin to ground would also help protect the pin, although they will slow things down by a few tens of microseconds.

A relay can be driven with a single transistor, as in the interfacing tutorial. Remember the diode, since a relay presents an inductive load.

A message may be output onto a serial LCD, with the "formatted string over UART" op.
Fri Oct 30 2009, 02:36:21
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