Other Parts Discussed in Thread: LDC1101
Hello everyone,
I've set up my LDC1101 to read inductance. I'm using the LDC1101EVM sensor and coil (7 uH and 390 pF). I've activated the L only measurements to get back the inductances only. However, my inductance values seem really jumpy. The inductance reading I get varies from around 3,051,846 to 2,500,000 - and this doesn't really change much when the coil is given exposure to a conductor.
I've written a struct for the purposes of writing to the registers of the LDC1101, below are the relevant commands I've written to set up my registers
// Configure power state
// ------------------------------------
LDC1101.B.WRITE.START_CONFIG.bit.FUNC_MODE = 0x01;
/* Comments
* --------
* 0x01 puts device in sleep mode
* */
// Configure Rp measurment dynamic range
// ------------------------------------
LDC1101.B.WRITE.RP_SET.bit.RP_MIN = 0b110;
LDC1101.B.WRITE.RP_SET.bit.RP_MAX = 0b000;
LDC1101.B.WRITE.RP_SET.bit.HIGH_Q_SENSOR = 0;
// Configure RP + L conversion interval
// ------------------------------------
LDC1101.B.WRITE.DIG_CONFIG.bit.RESP_TIME = 0x02;
LDC1101.B.WRITE.DIG_CONFIG.bit.MIN_FREQ = 0x0C;
// Configure additional device settings
// ------------------------------------
//LDC1101.B.WRITE.ALT_CONFIG.all = 0x00;
LDC1101.B.WRITE.ALT_CONFIG.bit.LOPTIMAL = 1;
LDC1101.B.WRITE.ALT_CONFIG.bit.SHUTDOWN_EN = 0;
// High Resolution L reference count
// ------------------------------------
LDC1101.B.WRITE.LHR_RCOUNT_LSB = 0xA0;
LDC1101.B.WRITE.LHR_RCOUNT_MSB = 0xAA;
// High Resolution L reference offet
// ------------------------------------
LDC1101.B.WRITE.LHR_OFFSET_LSB = 0x00;
LDC1101.B.WRITE.LHR_OFFSET_MSB= 0x00;
// High Resolution L configuration
// ------------------------------------
LDC1101.B.WRITE.LHR_CONFIG.bit.SENSOR_DIV = 0x0Right now, I'm just looking to get stable inductance readings. I was just wondering what I might be missing that is causing my readings to be so jumpy. I wonder if it's my external clock signal?
Best wishes,
Eric
