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got I2C demo working but stuff still needs to be moved out of here and into drivers

This commit is contained in:
Michael Ossmann 2012-06-03 14:55:51 -06:00
parent 770134b4d5
commit b55d006d02
2 changed files with 101 additions and 6 deletions
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11
examples/lpc43xx/hackrf-jellybean/i2c/README
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@ -2,4 +2,13 @@
README
------------------------------------------------------------------------------
This program exercises the I2C peripheral on Jellybean's LPC43xx.
This program exercises the I2C peripheral on Jellybean's LPC43xx. You can
scope SCL on P6 pin 3 and SDA on P6 pin 5. If Lemondrop is connected, LED1
will illuminate if I2C communication to the Si5351C on Lemondrop is successful.
Required Lemondrop -> Jellybean connections:
SCL: Lemondrop P7 pin 3 -> Jellybean P6 pin 3
SDA: Lemondrop P7 pin 5 -> Jellybean P6 pin 5
VCC: Lemondrop P4 pin 2, 4, or 6 -> Jellybean P17 pin 2, 4, or 6
GND: Lemondrop P5 -> Jellybean P13

96
examples/lpc43xx/hackrf-jellybean/i2c/i2cdemo.c
View File

@ -23,6 +23,11 @@
#include <libopencm3/lpc43xx/cgu.h>
#include <libopencm3/lpc43xx/i2c.h>
void gpio_setup(void)
{
GPIO2_DIR |= (1 << 1); /* Configure GPIO2[1] (P4_1) as output. */
}
//FIXME generalize and move to drivers
#define SCU_SFSI2C0_SCL_EFP (1 << 1) /* 3 ns glitch filter */
@ -75,12 +80,13 @@ void i2c0_init()
//FIXME assuming we're on IRC at 96 MHz
/* 400 kHz I2C */
I2C0_SCLH = 120;
I2C0_SCLL = 120;
//I2C0_SCLH = 120;
//I2C0_SCLL = 120;
/* 100 kHz I2C */
//I2C0_SCLH = 480;
//I2C0_SCLL = 480;
I2C0_SCLH = 480;
I2C0_SCLL = 480;
//FIXME not sure why this appears to run at about 290 kHz
/* clear the control bits */
I2C0_CONCLR = (I2C_CONCLR_AAC | I2C_CONCLR_SIC
@ -90,13 +96,93 @@ void i2c0_init()
I2C0_CONSET = I2C_CONSET_I2EN;
}
/* transmit start bit */
void i2c0_tx_start()
{
I2C0_CONCLR = I2C_CONCLR_SIC;
I2C0_CONSET = I2C_CONSET_STA;
while (!(I2C0_CONSET & I2C_CONSET_SI));
I2C0_CONCLR = I2C_CONCLR_STAC;
}
/* transmit data byte */
void i2c0_tx_byte(u8 byte)
{
if (I2C0_CONSET & I2C_CONSET_STA)
I2C0_CONCLR = I2C_CONCLR_STAC;
I2C0_DAT = byte;
I2C0_CONCLR = I2C_CONCLR_SIC;
while (!(I2C0_CONSET & I2C_CONSET_SI));
}
/* receive data byte */
u8 i2c0_rx_byte()
{
if (I2C0_CONSET & I2C_CONSET_STA)
I2C0_CONCLR = I2C_CONCLR_STAC;
I2C0_CONCLR = I2C_CONCLR_SIC;
while (!(I2C0_CONSET & I2C_CONSET_SI));
return I2C0_DAT;
}
/* transmit stop bit */
void i2c0_stop()
{
if (I2C0_CONSET & I2C_CONSET_STA)
I2C0_CONCLR = I2C_CONCLR_STAC;
I2C0_CONSET = I2C_CONSET_STO;
I2C0_CONCLR = I2C_CONCLR_SIC;
}
#define SI5351C_I2C_ADDR (0x60 << 1)
#define I2C_WRITE 0
#define I2C_READ 1
/* write to single register */
void si5351c_write_reg(uint8_t reg, uint8_t val)
{
i2c0_tx_start();
i2c0_tx_byte(SI5351C_I2C_ADDR | I2C_WRITE);
i2c0_tx_byte(reg);
i2c0_tx_byte(val);
i2c0_stop();
}
/* read single register */
uint8_t si5351c_read_reg(uint8_t reg)
{
uint8_t val;
/* set register address with write */
i2c0_tx_start();
i2c0_tx_byte(SI5351C_I2C_ADDR | I2C_WRITE);
i2c0_tx_byte(reg);
/* read the value */
i2c0_tx_start();
i2c0_tx_byte(SI5351C_I2C_ADDR | I2C_READ);
val = i2c0_rx_byte();
i2c0_stop();
return val;
}
int main(void)
{
int i;
gpio_setup();
i2c0_init();
//TODO I2C tx/rx
while (1) {
if (si5351c_read_reg(0) == 0x10)
gpio_set(GPIO2, GPIOPIN1); /* LED on */
else
gpio_clear(GPIO2, GPIOPIN1); /* LED off */
for (i = 0; i < 1000; i++) /* Wait a bit. */
__asm__("nop");
}
return 0;
}