Canberk Sönmez / Mbed 2 deprecated LTC2945_Monitor

LTC2945 ported

Dependencies:   mbed

main.cpp@4:d32eaca53504, 2017-09-20 (annotated)

Committer:
odtulumbedder
Date:
Wed Sep 20 09:03:56 2017 +0000
Revision:
4:d32eaca53504
Parent:
3:2ab78e7e8518 
I decided to remove the C-linkage specifiers, they are really not that necessary.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
odtulumbedder 3:2ab78e7e8518 1 /**
odtulumbedder 3:2ab78e7e8518 2 * Canberk Sönmez,
odtulumbedder 3:2ab78e7e8518 3 * code is taken from the official tutorial for Linduino platform.
odtulumbedder 3:2ab78e7e8518 4 *
odtulumbedder 3:2ab78e7e8518 5 * I couldn't get power measurement working.
odtulumbedder 3:2ab78e7e8518 6 */
odtulumbedder 3:2ab78e7e8518 7
odtulumbedder 3:2ab78e7e8518 8 #include <mbed.h>
odtulumbedder 0:6be57f391716 9 #include <I2C.h>
odtulumbedder 0:6be57f391716 10 #include "LT_I2C.h"
odtulumbedder 0:6be57f391716 11 #include "LTC2945.h"
odtulumbedder 0:6be57f391716 12
odtulumbedder 3:2ab78e7e8518 13 /* initialize I2C communications object */
odtulumbedder 3:2ab78e7e8518 14 I2C i2c(p28, p27);
odtulumbedder 3:2ab78e7e8518 15 /* sda, scl */
odtulumbedder 0:6be57f391716 16
odtulumbedder 3:2ab78e7e8518 17 /* LTC2945 I2C address, it's shifted 1 bit right,
odtulumbedder 3:2ab78e7e8518 18 * as it's given in 8-bit form in the datasheet,
odtulumbedder 3:2ab78e7e8518 19 * and the library does shifting again, causing
odtulumbedder 3:2ab78e7e8518 20 * communication problems
odtulumbedder 3:2ab78e7e8518 21 * 0xDE, since ADR0 and ADR1 are both grounded. */
odtulumbedder 2:7e390bcce297 22 const int ltc2945_addr = 0xDE>>1;
odtulumbedder 0:6be57f391716 23
odtulumbedder 3:2ab78e7e8518 24 /* ASSERT macro, reports debugging information if
odtulumbedder 3:2ab78e7e8518 25 * the condition inside paranthesis is not satisfied. */
odtulumbedder 3:2ab78e7e8518 26 #define ASSERT(x) if (! (x)) { printf("%s:%d %s failed!\n", \
odtulumbedder 3:2ab78e7e8518 27 __FILE__, __LINE__, #x); }
odtulumbedder 2:7e390bcce297 28
odtulumbedder 3:2ab78e7e8518 29 /*
odtulumbedder 3:2ab78e7e8518 30 * Program entry point.
odtulumbedder 3:2ab78e7e8518 31 */
odtulumbedder 3:2ab78e7e8518 32 int main() {
odtulumbedder 3:2ab78e7e8518 33 /* initialize ported LT_I2C library and check if it's fine */
odtulumbedder 3:2ab78e7e8518 34 ASSERT(lt_i2c_init_attach(&i2c) == LT_I2C_INIT_FINE);
odtulumbedder 0:6be57f391716 35
odtulumbedder 3:2ab78e7e8518 36 /* change I2C frequency, to have it working with optocoupled circuit */
odtulumbedder 3:2ab78e7e8518 37 i2c.frequency(1000);
odtulumbedder 0:6be57f391716 38
odtulumbedder 3:2ab78e7e8518 39 /* typical LSB values, LSB is the smallest change in the value per least
odtulumbedder 3:2ab78e7e8518 40 * significant bit. */
odtulumbedder 3:2ab78e7e8518 41 // typical deltaSense LSB weight in volts
odtulumbedder 3:2ab78e7e8518 42 const float LTC2945_DELTA_SENSE_lsb = 2.5006105E-05;
odtulumbedder 3:2ab78e7e8518 43 // typical Vin LSB in volts
odtulumbedder 3:2ab78e7e8518 44 const float LTC2945_VIN_lsb = 2.5006105E-02;
odtulumbedder 3:2ab78e7e8518 45 // typical POWER LSB in V^2
odtulumbedder 3:2ab78e7e8518 46 const float LTC2945_Power_lsb = 6.25305E-07;
odtulumbedder 0:6be57f391716 47
odtulumbedder 3:2ab78e7e8518 48 // power code, which is read as an integer and converted later
odtulumbedder 0:6be57f391716 49 int32_t power_code;
odtulumbedder 3:2ab78e7e8518 50 // current code (same as above)
odtulumbedder 0:6be57f391716 51 uint16_t current_code;
odtulumbedder 3:2ab78e7e8518 52 // Vin code (same as above)
odtulumbedder 0:6be57f391716 53 uint16_t VIN_code;
odtulumbedder 3:2ab78e7e8518 54 // adc command is constructed and sent to the LTC2945
odtulumbedder 0:6be57f391716 55 uint8_t adc_command;
odtulumbedder 3:2ab78e7e8518 56 // ACKnowledge bit, received if the operation is successful
odtulumbedder 0:6be57f391716 57 int8_t ack;
odtulumbedder 3:2ab78e7e8518 58 // resistance value
odtulumbedder 0:6be57f391716 59 float resistor;
odtulumbedder 3:2ab78e7e8518 60 // calculated power value
odtulumbedder 0:6be57f391716 61 float power;
odtulumbedder 3:2ab78e7e8518 62 // calculated current value
odtulumbedder 0:6be57f391716 63 float current;
odtulumbedder 3:2ab78e7e8518 64 // calculated VIN value
odtulumbedder 0:6be57f391716 65 float VIN;
odtulumbedder 0:6be57f391716 66
odtulumbedder 3:2ab78e7e8518 67 // the resistance value (calibrate if necessary)
odtulumbedder 3:2ab78e7e8518 68 resistor = 0.26518f;
odtulumbedder 3:2ab78e7e8518 69
odtulumbedder 3:2ab78e7e8518 70 // we are in an infinite loop, continuously print values
odtulumbedder 0:6be57f391716 71 while (true) {
odtulumbedder 3:2ab78e7e8518 72 ack = 0; // never forget resetting ack
odtulumbedder 3:2ab78e7e8518 73 // build adc_command, set LTC2945 in continuous mode
odtulumbedder 3:2ab78e7e8518 74 adc_command = LTC2945_SENSE_MONITOR | LTC2945_CONTINUOUS_MODE;
odtulumbedder 3:2ab78e7e8518 75 /* send command by LTC2945_write command.
odtulumbedder 3:2ab78e7e8518 76 * we use |= here not &= to accumulate success state
odtulumbedder 3:2ab78e7e8518 77 * as in the API 0 means successful, and 1 means failure.
odtulumbedder 3:2ab78e7e8518 78 * if we have ACKnowledge, then we are successful */
odtulumbedder 3:2ab78e7e8518 79 ack |= LTC2945_write(ltc2945_addr, LTC2945_CONTROL_REG, adc_command);
odtulumbedder 2:7e390bcce297 80
odtulumbedder 3:2ab78e7e8518 81 /* read LTC2945_POWER_MSB2_REG register, containing power code
odtulumbedder 3:2ab78e7e8518 82 * (it's a 24-bit register) */
odtulumbedder 3:2ab78e7e8518 83 ack |= LTC2945_read_24_bits(
odtulumbedder 3:2ab78e7e8518 84 ltc2945_addr,
odtulumbedder 3:2ab78e7e8518 85 LTC2945_POWER_MSB2_REG,
odtulumbedder 3:2ab78e7e8518 86 &power_code);
odtulumbedder 3:2ab78e7e8518 87 /* and convert it to power, using LTC2945_code_to_power */
odtulumbedder 3:2ab78e7e8518 88 power = LTC2945_code_to_power(power_code, resistor, LTC2945_Power_lsb);
odtulumbedder 2:7e390bcce297 89
odtulumbedder 3:2ab78e7e8518 90 /* read LTC2945_DELTA_SENSE_MSB_REG register, containing deltaSENSE
odtulumbedder 3:2ab78e7e8518 91 * voltage code (it's a 12-bit register) */
odtulumbedder 3:2ab78e7e8518 92 ack |= LTC2945_read_12_bits(
odtulumbedder 3:2ab78e7e8518 93 ltc2945_addr,
odtulumbedder 3:2ab78e7e8518 94 LTC2945_DELTA_SENSE_MSB_REG,
odtulumbedder 3:2ab78e7e8518 95 &current_code);
odtulumbedder 3:2ab78e7e8518 96 /* and convert it to current using resistance
odtulumbedder 3:2ab78e7e8518 97 * via LTC2945_code_to_current */
odtulumbedder 3:2ab78e7e8518 98 current = LTC2945_code_to_current(
odtulumbedder 3:2ab78e7e8518 99 current_code,
odtulumbedder 3:2ab78e7e8518 100 resistor,
odtulumbedder 3:2ab78e7e8518 101 LTC2945_DELTA_SENSE_lsb);
odtulumbedder 3:2ab78e7e8518 102
odtulumbedder 3:2ab78e7e8518 103 /* read LTC2945_VIN_MSB_REG register, containing Vin voltage code
odtulumbedder 3:2ab78e7e8518 104 * (it's a 12-bit register) */
odtulumbedder 3:2ab78e7e8518 105 ack |= LTC2945_read_12_bits(
odtulumbedder 3:2ab78e7e8518 106 ltc2945_addr,
odtulumbedder 3:2ab78e7e8518 107 LTC2945_VIN_MSB_REG,
odtulumbedder 3:2ab78e7e8518 108 &VIN_code);
odtulumbedder 3:2ab78e7e8518 109 /* and convert it to voltage directly */
odtulumbedder 3:2ab78e7e8518 110 VIN = LTC2945_VIN_code_to_voltage(VIN_code, LTC2945_VIN_lsb);
odtulumbedder 3:2ab78e7e8518 111
odtulumbedder 3:2ab78e7e8518 112 /* we must have ack = 0 if all the operations above are successful! */
odtulumbedder 0:6be57f391716 113 ASSERT(ack == 0);
odtulumbedder 2:7e390bcce297 114
odtulumbedder 3:2ab78e7e8518 115 /* print it, only 2 digits after dot */
odtulumbedder 3:2ab78e7e8518 116 printf("power: %.2f, current: %.2f, Vin: %.2f\n", power, current, VIN);
odtulumbedder 3:2ab78e7e8518 117
odtulumbedder 3:2ab78e7e8518 118 /* wait 500 ms */
odtulumbedder 2:7e390bcce297 119 wait_ms(500);
odtulumbedder 0:6be57f391716 120 }
odtulumbedder 0:6be57f391716 121 }