MSP430FR5959: Communication error problem of MSP430FR5959 in IrDA mode

Hi Matthew,

Thank you for your reply!

I'm sorry I uploaded a protected project.

The unlocked software is as follows:

MSP430FR5xx_irda_sample.zip

Best regards.

Cruijff

Cruijff,

Thank you for sending the project! If you suspect a problem in the MSP430 IrDA module then using this App Report (SLAA202A) may help point you in the right direction in resolving your issue. The "Implementing IrDA with the MSP430" App Report goes over many important aspects to keep in mind, on a hardware and software level, when incorporating IrDA in a project.

Best regards,

Matt Calvo

Matt,

Thank you for the reply and sending the App report.

I have additional questions.

[question]

I tested whether IrDA communication error occurred on the onelaunchPad MSP - EXP430FR5969.
TXD and RXD are not connected outside but loopback mode is enabled (UCLISTEN = 1).

The results are as follows:

• In the first communication, the correct value was saved in the receive data buffer "UCRXBUF".
• In the second and subsequent, an incorrect value was saved in "UCRXBUF", and a parity error and a framing error were detected.

The loopback software is as follows.

IrDA_MSP-EXP430FR5969_sample.zip

Is there a problem with the setting of software?

Best regards.

Cruijff

Cruijff,

I have found a TI Design that successfully implements IrDA communication, it is called Single Bidirectional Infrared LED Communication Port Reference Design.

On the webpage for that TI Design you can download the User Guide and the software associated with it in order to analyze how they successfully implemented our IrDA feature and it should help you to debug your code to see if there exists a problem with the setting of software on your project.

Best regards,

Matt Calvo

Hi.

I'm sorry for the late reply.
While experimenting, I changed the internal receive filter (UCIRRXFE) to invalid.
Then, no error occurred.

I tested it in the following two cases.

---------------------------
[case 1]

When communicating MSPs 430 in IrDA mode with IrDA Infrared communication Module(RPM871-H14).
The hardware configuration is as follows:

[(MSP430FR5959)-(IrDA Receiver)] - (RPM871-H14) < ---
--- > (RPM871-H14) - [(IrDA Transmitter)-(MSP430FR5959)]
---------------------------
[case 2]
I tested whether IrDA communication error occurred on the onelaunchPad MSP - EXP430FR5969.
TXD and RXD are not connected outside but loopback mode is enabled (UCLISTEN = 1).
---------------------------

The setting values are as follows:

---------------------------
<Setting transmission pulse width>
The measurement results are as follows :
BaudRate : 115200bps
IrDA Transmission pulse : 2.3[us]

---------------------------
<Setting the receive pulse width>
Minimum receive pulse width t(PULSE) = 2.3us
tWAKE = 0 (when the device is in active mode.)
fBRCLK = 8MHz

UCIRRXFLx = (t(PULSE) - t(WAKE)) * 2 * (fBRCLK) - 4

= (2.3 - 0) * 2 * 8 - 4 = 32

---------------------------

In addition to UCIRRXFLx = 32, I tried adjusting from 20 (= (1.5 - 0) * 2 * 8 - 4) to 32 with various values, but the result was the same.

Is there a mistake in the setting value?
Could you give me advice on internal filters?

Best regards.
Cruijff

Hi Matt.

I'm sorry for the late reply.
Thank you for providing the information.

As the system team commented,I checked the RX pin but occasionally some noise was in it.
So I enabled the receive filter and further reduced the filter width.
When this experiment result comes out, I will post again.

Thank you for your cooperation.
Best regards,

Cruijff