Hello, I am programming nRF51 on Keil. My app uses BLE with softdevice S130, PWM, and I2C communication with two sensors. Also RTT for debugging.
I have already reached the limit code size of Keil with free license, 32kB. I am using Optimization level 0 because when I put 1 or higher mmy app doesn't work anymore, but that is another question I haven't had time to debug yet.
My question: is it normal that putting just one call in main loop to this function, using optimization level 0, code size increases from 28kB to 35kB (7kB difference!)?? Or I am doing something wrong?
Thank you very much for your time,
Luis Rodenas
This is the function (actually splitted in 2 functions):
uint32_t MS5611Read2(uint8_t CMD, uint8_t OSR) // temperature data read
{
uint8_t data[3] = {0,0,0 };
uint32_t err_code;
err_code = twi_write_single2((CMD | OSR), 1);
APP_ERROR_CHECK(err_code);
switch (OSR)
{
case ADC_256:
nrf_delay_ms(1);
break; // delay for conversion to complete
case ADC_512:
nrf_delay_ms(3);
break;
case ADC_1024:
nrf_delay_ms(4);
break;
case ADC_2048:
nrf_delay_ms(6);
break;
case ADC_4096:
nrf_delay_ms(10);
break;
}
twi_read_burst2(0x00, data, 3);
return (uint32_t) (((uint32_t) data[0] << 16) | (uint32_t) data[1] << 8 | data[2]); // construct PROM data for return to main program
}
void ms5611_read2(){
uint32_t D1 = 0, D2 = 0; // raw MS5611 pressure and temperature data
double dT, OFFSET, SENS, T2, OFFSET2, SENS2; // First order and second order corrections for raw S5637 temperature and pressure data
double Temperature, Pressure; // stores MS5611 pressures sensor pressure and temperature
D1 = MS5611Read2(ADC_D1, OSR); // get raw pressure value
D2 = MS5611Read2(ADC_D2, OSR); // get raw temperature value
dT = D2 - Pcal[5]*pow(2,8); // calculate temperature difference from reference
OFFSET = Pcal[2]*pow(2, 16) + dT*Pcal[4]/pow(2,7);
SENS = Pcal[1]*pow(2,15) + dT*Pcal[3]/pow(2,8);
Temperature = (2000 + (dT*Pcal[6])/pow(2, 23))/100; // First-order Temperature in degrees Centigrade
// Second order corrections
if(Temperature > 20)
{
T2 = 0; // correction for high temperatures
OFFSET2 = 0;
SENS2 = 0;
}
if(Temperature < 20) // correction for low temperature
{
T2 = dT*dT/pow(2, 31);
OFFSET2 = 5*(100*Temperature - 2000)*(100*Temperature - 2000)/2;
SENS2 = 5*(100*Temperature - 2000)*(100*Temperature - 2000)/4;
}
if(Temperature < -15) // correction for very low temperature
{
OFFSET2 = OFFSET2 + 7*(100*Temperature + 1500)*(100*Temperature + 1500);
SENS2 = SENS2 + 11*(100*Temperature + 1500)*(100*Temperature + 1500)/2;
}
// End of second order corrections
//
Temperature = Temperature - T2/100;
OFFSET = OFFSET - OFFSET2;
SENS = SENS - SENS2;
Pressure = (((D1*SENS)/pow(2, 21) - OFFSET)/pow(2, 15))/100; // Pressure in mbar or Pa/100
float altitude = 145366.45*(1. - pow((Pressure/1013.25), 0.190284));
char buffer [50];
sprintf(buffer, "%f", altitude);
SEGGER_RTT_WriteString(0, buffer);
}
