UM0401 STMICROELECTRONICS | Alldatasheet
Document overview
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Technical content
Datasheet sections
- 1 Getting started
- 1.1 System requirements
- 1.2 Package contents
- 1.3 Software installation
- 1.4 Hardware installation
- 1.4.1 Power supply
- 1.4.2 Jumper settings
- 2 Running the STMPE801 port exp ander GUI
- 2.1 Running internal registers of STMPE801
- 2.2 Programming GPIO
- 2.3 Power modes
- 2.4 Configuring interrupts
- 3 Using the external I 2C master
- 4 Demo board footprint
- 5 Revision history
User manual for eight bit port expander STMPE801 demonstration board Introduction This document explains the functioning of the demo board for the port expander Chip STMPE801 with a PC GUI for reading and writing to the eight GPIOs and controlling the I2C interface. The objective of this demonstration board is to display the capabilities of the 8-bit port expander (STMPE801) developed by STMicroelectronics using a Windows-based software application. The software application provides a user-friendly environment to test the port expander and verify its functionality. The board is controlled by the GUI through the parallel port in the PC. The power to the board should come from an external 5 V constant DC power supply. The PC based GUI acts as the I 2C host and controls the STMPE801 slave on the board. The eight GPIOs in the STMPE801 are accessible through headers and can be easily pulled high or low using jumpers. The GPIOs can be configured as outputs by writing to the appropriate registers using the GUI. All these interfaces are controlled by using I communication between Host and Slave devices. In addition, the hardware has a provision for controlling the STMPE801 through an external I2C master.
1 Getting started
1.1 System requirements
In order to use the port expander demonstration board with the Windows operating system, a recent version of Windows, such as Windows XP or Windows 2000 must be installed on the PC. The user must have administrative rights to install the executable and launch it. The version of the Windows OS installed on your PC may be determined by clicking on the "System" icon in the Control Panel.
1.2 Package contents
The port expander demo board includes the following items:
- Hardware content: – One demonstration board – One parallel port cable
- Software content: – PC executable software (STMPE801_GUI) to be used along with demo board – A DLL file to support the executable (io.dll) to be installed in the same directory as the executable file. – Source code (written in Borland Delphi)
- Documentation: –U s e r m a n u a l – Schematic of the hardware
1.3 Software installation
The GUI is a simple executable that can be run even from a USB flash drive. The only requirement is that the user must have administrative rights on the system in order to open the accompanying DLL file. The GUI can be started by double-clicking on the file STMPE801_GUI.exe. When the exe file is opened, the GUI resembles Figure 1 below:
Figure 1. GUI start up screen
1.4 Hardware installation
Figure 2 below shows the snapshot of the demonstration board. Figure 2. Port expander board
1.4.1 Power supply
and Vpull-up voltages by adjusting the Resistor divider components. where, the VOUT we need is 1.8 V, VREF is 1.25 V and IADJ is 50 µA. Vpull-up = 2.3 V in the demo board. Figure 3. Voltage regulation from +5 V supply (V IN)
1.4.2 Jumper settings
- JP10_1: as shown in Figure 4 below, the JP10_1 jumper should be set to power the voltage Regulators with +5V from the X1 and X2 connectors. This is the main power connection for all the components on the board.
Figure 4. JP10_1 for Power supply
- JP4_3: JP4_3 is the jumper used to select the I2C slave address as either 0x82 or 0x88. There are pull-down and pull-up resistors for the respective selection and these can be enabled by shorting the headers as shown in Figure 8.
Figure 8. JP4_3 setting for STMPE801 I
- JP6_3 and JP7_3: These jumpers are provided to isolate the STMPE801 chip from the rest of the board for troubleshooting. They can also be used as test points to measure the respective supply operating current. To supply the chip with the V CC and VIO, these jumpers should be shorted as shown in Figure 9.
Figure 9. JP6_3 and JP7_3 setting for STMPE801 V CC and VIO connections
2 Running the STMPE801 port expander GUI
- PC GUI
- Demonstration board The various jumpers on the board should be configured correctly before running the GUI. In order to run the GUI, the demo board must first be connected to the PC with the DB-25 parallel port cable and the power supply of +5 V should be provided. The user should login as administrator before running the GUI (STMPE801_DEMO.exe). This file should be run from the same directory as the io.dll file. When the GUI is successfully running, the startup screen resembles Figure 10. There are four tab options for testing the various device functionalities as explained in the following sections.
Figure 10. Screen shot of STMPE801 GUI startup screen
2.1 Running internal registers of STMPE801
error message as shown in Figure 12.
2.2 Programming GPIO
tab of the GUI as shown in Figure 13. Figure 13. GPIO Input state screen shot
Figure 14. GPIO Output state screen shot
2.3 Power modes
There are 2 functions that can be tested using this tab as shown in Figure 15.
- I2C shutdown
- Soft reset The STMPE801 slave devices can be put in Power down mode by clicking on the "I2C Shutdown" button. This shuts down the device and displays a message to press the reset button to resume normal device operation. Clicking the "Soft Reset" button performs the reset of the device. Like the other function tabs, the correct slave device should be chosen before clicking the buttons.
Figure 15. Entering in hibernate mode
2.4 Configuring interrupts
allows configuring the interrupt polarity and the masking of each individual GPIO. Figure 16. Interrupt setting tab screen shot
3 Using the external I 2C master
available on the JP17_2 connector as shown in Figure 18. Figure 18. External I 2C connector
- The jumper settings on JP55_2 and JP56_2 should be removed. (Refer to Figure 4)
- The SCLK of the master should be connected to pin 2 of JP17_2 and the SDAT of master should be connected to pin 4 of JP17_2.
- Pins 2 and 4 already have pull-up resistors connected to pull up the open drain SCLK and SDAT pins. If these resistors are not required, the resistors R4_2 and R5_2 should be removed from the demo board. In this mode, the PC GUI is not be available for the external I 2C master.
4 Demo board footprint
Figure 19. Demo board footprint
5 Revision history
Table 1. Revision history