Electronic Design

Cypress PSoC FirstTouch

The Cypress Semiconductor PSoC (programmable-systems-on-a-chip) microcontroller is a popular platform because of its ability to throw custom hardware at a problem without the complexity of an FPGA. The PSoC's (see Breaking News: Analog PSoC Family) soft architecture allow any mix of standard or specialized interfaces like its CapSense capacitive touch support. This time I take a look at a pair of PSoC platforms. The $29 PSoC FirstTouch is a USB-based development tool. The PSoC CY3121-CUSTOMER is more of a demo system, but it has enough hooks to make an interesting development platform. It contains four PSoC processors connected in a network. PSoC Overview The PSoC can be configured by PSoC Designer. This is an advanced tool that is used to configured the analog and digital blocks that surround the microcontroller. This is the first step in designing a PSoC system. The second is to program the microcontroller to take advantage of the customize interfaces. The two steps can be combined using the simpler PSoC Express (see Visual Design Tool Tackles Multiple MCUs). PSoC Express is also a free download from Cypress' website. It is a graphical tool that allows developers to choose from a set of peripherals that can be constructed from the analog and digital blocks as well as a set of code that implements a standard set of functions that can be linked to other components on the graphical canvas. First Look At FirstTouch FirstTouch consists of a USB-based debug module and a target board (FirstTouch MultiFunction Expansion Card) with CY8C21434 PSoC microcontroller. It highlights some of the range of peripherals that the PSoC can support like a capacitive touch and proximity sensor. In addition to the CY8C21434, the target board has a CapSense ‘Touch Button,’ a 7-element touch slider, and a proximity antenna connection. The antenna for the latter is simply a short piece of wire. There is also a light sensor, a thermistor for temperature measurement, a speaker, and a Red-Green-Blue triple LED cluster. There is also an I2C interface and four unused ADC/GPIO lines. Like similar systems, the target board can be programmed and tested attached to the USB dongle. It can then be removed and plugged into another host system like a robot. The PSoC Express software on the installation CD includes support for the various peripherals on the target board. Customer Demo Platform The PSoC CY3121-CUSTOMER can be used to demonstrate the flexibility of the PSoC, or, in this case, as host of PSoCs. The board is divided into four quadrants with their own PSoC chip. Each chips is a different type within the PSoC family. There is also a JTAG interface for each chip. They are independent and on single USB-based JTAG MiniProg adapter is included with the system. Each quadrant on the development board is connected together in a serial network. The pre-programmed applications in the collection show off the interaction between these systems using different displays and inputs found in each quadrant. There are a host of jumpers, headers, switch, potentiometers and options that are different for each quadrant. The system can be powered by a 9V battery or via a USB cable. One quadrant includes a 7-segment LED display. Another has a four pad capacitive touch system. PSoC Express allows developers to design multiprocessor systems like this. Getting Up and Running The installation for both platforms are essentially identical. Both include PSoC Express 3.0. It runs on a .NET enabled platform like Windows XP or Windows Vista. The installation CD handles the installation process and documentation placement quickly and easily. The FirstTouch version includes Express Pack 1, a set of objects for PSoC Express. Both platforms include a range of PSoC Express projects including the default applications. These are good starting points. I had used PSoC Express since V1.0 but just about anyone will be moving graphical wiring connections between objects on the graphical canvas within an hour or less. It is remarkably easy to be productive with PSoC Express. Other PSoC Resources PSoC Express is easy to use but there are still tips and tricks that any PSoC designer can use and they are highlighte in the book The Beginner’s Guide to PSoC Express by Oliver H. Bailey PSoC C compilers are available from a number of sources but if you are looking for the most compact software around, check out HiTech Software's Hi-Tech C PRO for the PSoC Mixed-Signal Array. This development environment has a C compiler that implements Omniscient Code Generation (OCG) technology Whole Program C Compiler Optimizes Across Modules. It is a global optimizer but it can be applied across separately compiled module. It is quite impressive. Related Links Cypress Semiconductor HiTech Software

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.