ez430 i2c problems

Steven Tran57967

Other Parts Discussed in Thread: MSP430F2274, SIMPLICITI

Hi, I am trying to run the i2c demos for msp430f2274 in msp430x22x4_uscib0_i2c_06. and msp430x22x4_uscib0_i2c_07.c from http://www.ti.com/lit/zip/slac123 (master tx single bytes and slave rx single bytes). I have connected two ez430s together on the i2c bus as master and slave. The master is connected to the computer for debugging. I use the master ez430 for VCC (3.6V from usb) and GND. However, while debugging the master gets stuck on

while (UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent

I measured SDA and SCL with logic analyzer but there are no changes. SDA stays at 2.6V (not 3.6) and SCL stays low despite the pullup resistors. What could be the problem? Thanks.

over 15 years ago

0 Priya Thanigai over 15 years ago

TI__Mastermind 26380 points

Hello,

This may be related to how the I2C lines are multiplexed with the CC radio.

Regards,

Priya

0 Steven Tran57967 over 15 years ago in reply to Priya Thanigai

Prodigy 60 points

Hi Priya, that worked. The examples run fine now. However how difficult would it be to use the radio and i2c at the same time? I have a scenario where an end point ez430 is reading a sensor through i2c and transmitting data using Simpliciti. The access point ez430 receives the data and communicates it through UART to a serial port.

0 Abu Alam61097 over 15 years ago in reply to Steven Tran57967

Prodigy 200 points

I am in a similar situation. Disabling and re-enabling the RF might be an overhead since I need to use both RF and I2c simultaneously, are there any other work arounds for this issue?

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ez430 i2c problems