// Adapted from send_8bit_serial_data()
void send_616bit_serial_data(struct uint640_t * data_full) {
unsigned char data; // data byte
// p_data points to the most significant byte in data_full
unsigned char * p_data = (unsigned char *) data_full;
p_data += (sizeof(struct uint640_t) - 1);
int i;
int delay;
// ?
output_low(SR_OUT);
// select device
output_high(SR_EN);
// send bits 640..(640-616)
for (i=0; i<616; i++) {
// Move to next byte after 8 bits
if ((i & 0x07) == 0) { // faster equivalence of (i % 8 == 0)
data = *p_data;
--p_data;
printf("Write byte: 0x%02x (0b%s).\n", data, byte_to_binary(data));
}
// consider leftmost bit
// set line high if bit is 1, low if bit is 0
if (data & 0x80)
output_high(SR_IN);
else
output_low(SR_IN);
// pulse clock to indicate that bit value should be read
output_low(SR_CK);
printf("-- write to register: 0x%02x (0b%s)\n", dest_register[0], byte_to_binary(dest_register[0]));
write_to_register();
for (delay = 0; delay < LED_DELAY; delay++);
// pulse clock to indicate that bit value should be read
output_high(SR_CK);
printf("-- write to register: 0x%02x (0b%s)\n", dest_register[0], byte_to_binary(dest_register[0]));
write_to_register();
for (delay = 0; delay < LED_DELAY; delay++);
// shift byte left so next bit will be leftmost
data <<= 1;
}
// deselect device
output_low(SR_EN);
}
void imu_init()
{
lock = 0;
i2c_open(&imuConn, PIN_IMU_SCL, PIN_IMU_SDA, 0);
// Gyro initialization.
// 22 -> 11011 Set internal clock and scale.
// 21 -> 9 Set sample rate.
// 23 -> 101 Trigger interrupt when new data is ready (extra int pins).
// 62 -> 1 Set clock source.
write_to_register(&imuConn, GYRO_ADDR, 0x16, 0x1A);
write_to_register(&imuConn, GYRO_ADDR, 0x15, 0x09);
write_to_register(&imuConn, GYRO_ADDR, 0x17, 0x05);
write_to_register(&imuConn, GYRO_ADDR, 0x3E, 1);
// Accel initialization.
// 45 -> 1000, 100 Wake it from sleep, keep it awake.
// 49 -> 01 Set the data range. 00->2, 01->4, 10->8, 11->16 (+- g).
write_to_register(&imuConn, ACCL_ADDR, 0x2D, 16);
write_to_register(&imuConn, ACCL_ADDR, 0x2D, 8);
write_to_register(&imuConn, ACCL_ADDR, 0x31, 0); // Might need to change this later.
//writeToRegister(&imuConn, ACCL_ADDR, 0x1E, -25/-4); -25 // Tuning values.
//writeToRegister(&imuConn, ACCL_ADDR, 0x1F, 12/-4); 12
//writeToRegister(&imuConn, ACCL_ADDR, 0x20, 249/4); 249
}
// Transmit byte serially, MSB first
// from: https://en.wikipedia.org/wiki/Bit_banging
void send_8bit_serial_data(unsigned char data) {
int i;
int delay;
// ?
output_low(SR_OUT);
// select device
output_high(SR_EN);
// send bits 7..0
for (i=0; i<8; i++) {
// consider leftmost bit
// set line high if bit is 1, low if bit is 0
if (data & 0x80)
output_high(SR_IN);
else
output_low(SR_IN);
// pulse clock to indicate that bit value should be read
output_low(SR_CK);
printf("-- write to register: 0x%02x (0b%s)\n", dest_register[0], byte_to_binary(dest_register[0]));
write_to_register();
for (delay = 0; delay < LED_DELAY; delay++);
// pulse clock to indicate that bit value should be read
output_high(SR_CK);
printf("-- write to register: 0x%02x (0b%s)\n", dest_register[0], byte_to_binary(dest_register[0]));
write_to_register();
for (delay = 0; delay < LED_DELAY; delay++);
// shift byte left so next bit will be leftmost
data <<= 1;
}
// deselect device
output_low(SR_EN);
}
