Posted on April 06, 2015 at 00:26Hello,
I try to find some topick with same problem. But every topick is without the solution of problem.
I have problem with I2C in 95% (yep, sometimes it works, after restart, it not work). I try to comunicate with STMPE811 via I2C. I setup GPIOs for I2C3 (PA8 and PC3) and I2C3 timing.
// Configure I2C3 (100kHz standard)
I2C3->CCR =
0xD9
;
// Clock control - Th&Tl = CCR*PCLK => 5us
I2C3->CR2 |= (APB1clk /
1000000
);
// Freq of APB1 in MHz
I2C3->CR1 |= I2C_CR1_ACK;
// Acknowledge returned after
I2C3->OAR1 |=
0x4000
;
// Bit 14 Should always be kept at 1 by software. ?????? WTF!? OK, But why?
I2C3->TRISE = (APB1clk /
1000000
) +
1
;
// Rise time = 1000ns
// Enable peripheral
I2C3->CR1 |= I2C_CR1_PE;
// Enable peripheral
Next I tryed to read an ID from STMPE811. I set bit START in CR1 and wait for SB bit.
// Generate start condiction
I2C3->CR1 |= I2C_CR1_START;
while(!(I2C3->SR1 & I2C_SR1_SB))
// Wait to SB
Voltages on lines are:
SDA 0.1V
SCL 3.05V
But SB bit is not set, never. It always is stuck in cycle.
Can someone help with it?
Thanks for any response.
#i2c #stm32f429discovery #touchpad
