The Start of the 2nd Stage USB Project

Since the AC to DC 15V power supply with DC motor testing (as shown in the picture below) and the Visual Basic Coding are successfully completed, now it is the time move on to the next stage.


USB 24 I/O MK3 Input Tester Board
The design was completed and hardwares components were bought from SS2 PJ and ready to be assembled anytime. Some modifications to original design are required due to project target to replace the old 8255 PIT board. Since the connectors pins assignment are different, so two types of IDC 40P female adapter needs to be assembled. Yet another, the USB board do not have 12VDC supply. This means that I have to add an external 12VDC from other sources such as an AC to DC 12V power supply.

8255 PIT I/O Test Board
This part is actually a twofold mission. First, it's purpose is to help Mr Khow to familiarize with the PC interfacing world. Next it is to upgrade the old test board that I did for 8255 that comprise 5 output with a few connectors missing. Now it will be upgraded to 5 input and 5 output with full featured connectors.
Before he will proceed to the circuit assembly, first I have to redrawn the design for the upgrade. Next he himself have to troubleshoot the IDC 40PF board connectors to 32pin screw type interface board. The reason is just simply I lost my circuit design. Since it's quite simple, so the best way for him to learn to do it hands on.

Here is the list of today's purchase.