Frequently Asked Questions

Where is the documentation, and what should I read first?

The concept behind the hardware and firmware and many more details are described in the paper " Design of an enhanced TP-UART based KNX PC interface" by Georg Neugschwandtner and Andreas Fernbach. It was presented at the KNX Scientific Conference in St. Katelijne-Waver in 2008. Two errata are known:

  • Page 5: "However, the MSP430 starts up fast enough to correctly receive the service even if the TP-UART is allowed to delay its startup by directly connecting the reset pins." This is not correct. If the reset button is pressed (or RTS is connected as a reset signal), both the TP-UART and the MSP430 are reset; in this case, the MSP430 will miss the Reset.indication service. If the reset pins were directly connected, the situation would be equivalent.
  • Page 16: The "test and demonstration program for the PC side" was not released as open source (yet).

"An enhanced TP-UART interface board" by Andreas Fernbach (his bachelor thesis) also briefly covers the overall concept and requirements, but focuses on the hardware and firmware implementation. This report does not describe the most recent version of the PCB; for v1.3 (2010-03-01), the following things have changed:

  • The diode between the MSP430 RST pin and the reset button is no longer present (RST is not an output).
  • The power supply board now contains a diode to prevent damage when an AC adapter and a battery are connected simultaneously.
  • The outer pads of X1 now have the correct distance for a standard "Type 5.1" TP connector.

There is some overlap between these two documents, but each contains information that cannot be found elsewhere. The "Notes" section on this website basically picks up where these documents left off.

The text files in the download package also cover the most important hardware features. The firmware source files contain extensive comments.

Are there any bugs?

So far, no one has reported any. If you want, you may consider it a bug that we left out two capacitors that are recommended in the "typical application circuit" (C5, C6). Also, EXT PWR V+ on ACTIface could be connected between D3 and X3 (instead of after D3) to provide protection in case the power supply board is connected with reversed polarity.

Where can I buy this interface?

Sorry, but we currently do not know of anyone who sells kits or assembled interfaces. If you feel like changing this, let us know so we can put your address here!

How do I load the firmware from the package?

Get a JTAG adapter. The connector on ACTIface is designed for the TI "FET" adapters (and compatibles).

Download TI Code Composer Studio v4 (MCU Core Edition, TMDFCCS-MCULTD).

Then do the following - this is largely taken from page 10 (Section 1.2) in the "Code Composer Studio v4.1 User's Guide for MSP430" (SLAU157M):

  1. Start Code Composer Studio: Start > All Programs > Texas Instruments > Code Composer Studio v4.1 > Code Composer Studio v4.1.
  2. Create a new Project by selecting File > New > CCS Project.
  3. Enter a project name (e.g., "ACTIface") and click next.
  4. (Leave Project Type set at MSP430.)
  5. Click next twice to get to the CCS Project Settings page. Select the Device Variant used in the project: MSP430F123 or MSP430F1232.
  6. Add all necessary files (main.c, pins.h, swuart.c, swuart.h) to the project by clicking Project > Add Files to Active Project
  7. Configure the (JTAG) debug interface by opening the *.ccxml file in the project (double-click it within Code Composer Studio to get pull-down and/or tree edit controls). If you are using a USB interface, you likely do not need to touch the defaults; we tested this with a parallel port interface (MSP-FETP430IF 1.4). Support for parallel port interfaces must be selected during CCS installation.
  8. To compile the code and download the application to the target device, go to Target > Debug Active Project
  9. The application may be started by selecting Target > Run (F8) or clicking the Play button on the toolbar.