I am building a system using SPI. I have implemented several configurations on a breadboard and they work great. I use the following boards (sorry in japanese) that are basically fancy versions of the PIC 18F4553 and 18F2553.
The problem is when I tried to put this configuration on a perfboard, they fail. In one case they transmit correct characters sometimes and incorrect other times. In the other case the slave only transmits 0xFF.
I have checked and double checked. The connections are ok. The programs work (on the breadboard that is) correctly. I have run out of ideas of what could be wrong.
I know it is a mess of cables but I ve originally neat thin lead cables on the back but they didn't work so I ve tried these cables...
Any, and I mean any ideas that can give me some light are welcomed. Need some help here.
Wait, you said it does not work on a breadboard as in your picture with long wires, so which is it, it works or not? Do you mean it works if you run a simulation? I am having trouble viewing your schematic.
Wait, you said it does not work on a breadboard as in your picture with long wires, so which is it, it works or not? Do you mean it works if you run a simulation? I am having trouble viewing your schematic.
That's exactly what I mean. Now that I have looked again at a close up of the photo you posted, I can see that you have fitted 100nF caps across the supply pins, try adding say a 10uF cap right beside each of them. Also, keep your inter-connect wiring short.