Hello Dudes.a few month ago i bought one HY-LPC1788-CoreBoard (Gold Color!) And I started to using it in my project.Fortunately,I Could run the LCD,Touch & USART and THE RED LED on the LPC1788.But If i change the PORT and PIN it don't work. for example when i choose the on board led (P2.21) its working good and after that when i change the port (for example change P2.21 to P3.21 OR P2.21 to P0.21) it is not working. What is wrong with this LPC1788-CoreBoard !?? and this is my code.... 0up.ir/do.php Tanx.
Probe every pin that could be conceivably be 57. Or maybe all 60 pins to see if any of the pins are toggling. This is case you are miscounting or the schematic is being misread. or the schematic has a mistake.
Sounds complex, when it's so much easier to measure the voltage directly on the processor pin.
And this is best to do with an oscilloscope - it is able to clearly show if two output pins collide by showing a square wave with low amplitide but potentially very large offset. So a pin collision could result in a square wave between 2.7 and 3.3V Or between 1.2 and 3.3V or between 1.2 and 1.7V Or between 3.1 and 3.3V. It's just a question of how powerful the two fighting outputs are in relation to each other. Even if the pin is grounded or connected to VCC, there is normally enough resistance (unless the pin got directly connected to ground or power plane) to see a voltage difference when the pin "fights". And in that case it would normally also be visible on the current consumption, since a shorted GPIO pin puts up a significant fight.
Without an oscilloscope, the frequency must be reduced enough that a voltmeter will be able to correctly measure and present the voltages for both "high" and "low" even when the voltage difference is so small that it might not be obvious that there is a square wave there. So it would probably be best so go for maybe five seconds low, five seconds high, i.e. 0.1Hz.
If the processor registers have the correct values - i.e. no memory overwrite or following pin initializations overwrites the original configuration - then the datasheet for the processor will perfectly well tell exactly which port pin that gets affected by a specific action. So there will not be any reason to consider the action showing up on another pin - except that in some situations it's possible to configure the processor so that the same action can be emitted on more than one pin. More than one pin can react to the same match condition for a specific timer.