I have been trying my new 18x high power project board and am currently trying to get it to just output high and low levels to output ports 1-3 to drive LEDs.
The code and programming seems sucessful, if i put a meter on the output pins on the PICAXE chip then all is good and correct, i see the low/high switching that i am expecting. The problem comes when I try to drive the LED via the FET's on the board.
The FET doesn't seem to ground the pins (for example pin0 for outpin0) as the diagram shows. I have also tried to see whether the high/low levels as measured on the PIC output pins are reaching the legs of the FET and they don't appear to be. I understand that the output ports 1-3 consist of a fixed +V power pin and a FET switched ground, it's just that the ground doest seem to be switching. I currently have 6 of these boards and none are working.
Any ideas what I am doing wrong? This seems like it should be really simple and yet I cannot get it to work. Incidentally I currently do not have the L293D motor driver IC in place as the data sheet says it is optional (and I dont need to drive motors right now) also the circuit diagram doesnt show it being needed to just switch output pins 1-3 so this shouldnt affect them right?
Any advice greatly received
Darryl
The code and programming seems sucessful, if i put a meter on the output pins on the PICAXE chip then all is good and correct, i see the low/high switching that i am expecting. The problem comes when I try to drive the LED via the FET's on the board.
The FET doesn't seem to ground the pins (for example pin0 for outpin0) as the diagram shows. I have also tried to see whether the high/low levels as measured on the PIC output pins are reaching the legs of the FET and they don't appear to be. I understand that the output ports 1-3 consist of a fixed +V power pin and a FET switched ground, it's just that the ground doest seem to be switching. I currently have 6 of these boards and none are working.
Any ideas what I am doing wrong? This seems like it should be really simple and yet I cannot get it to work. Incidentally I currently do not have the L293D motor driver IC in place as the data sheet says it is optional (and I dont need to drive motors right now) also the circuit diagram doesnt show it being needed to just switch output pins 1-3 so this shouldnt affect them right?
Any advice greatly received
Darryl