April 2005, Issue 177

Simple USB Data Acquisition

SWITCHING TO ARM?

I hope you now have a better understanding of ARM-based microcontrollers, USB-to-UART bridges, and the process of implementing simple GUIs. You can combine all three to make a simple data acquisition device. 

The new ARM microcontrollers like the LPC2138 are opening doors for designers, many of whom are now questioning the use of the venerable 8-bit microcontroller for some applications. When you account for the ARM7 core’s processing power, low-power consumption, vast number of peripherals, memory size, tool/debug support, and incredibly small physical footprint, switching to a 32-bit ARM microcontroller may be a reasonable choice.

The USB-to-UART bridges like the CP2101 make it simple to update UART peripherals on microcontrollers (or legacy RS-232 devices) and enable USB connectivity. Embedded code isn’t required to make this transition, so the update process is fairly seamless. The virtual COM port drivers provided by companies like Silicon Labs also allow PC applications, such as the Visual Basic GUI I created, to send and receive USB data without additional code overhead.

The Visual Basic-based GUI allows for a professional-looking GUI in an easy-to-use design environment. The built-in component controls put the complex pieces in a simple format that you can easily integrate into your application. The language should be familiar to anyone with BASIC language experience. Explore these topics in greater detail before you begin your project. Good luck!