Hardware IO control: mirrors, lock in
lockin.h@0:c19dc1d8b225, 2011-10-17 (annotated)
- Committer:
- mbedalvaro
- Date:
- Mon Oct 17 13:23:06 2011 +0000
- Revision:
- 0:c19dc1d8b225
I wonder if perhaps it would be better to avoid a hardwareIO object, and instead have a set of global hardware functions... I think I will do this in the next revisions of this library
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
mbedalvaro | 0:c19dc1d8b225 | 1 | #ifndef MBED_LOCKIN_H |
mbedalvaro | 0:c19dc1d8b225 | 2 | #define MBED_LOCKIN_H |
mbedalvaro | 0:c19dc1d8b225 | 3 | |
mbedalvaro | 0:c19dc1d8b225 | 4 | #include "mbed.h" |
mbedalvaro | 0:c19dc1d8b225 | 5 | #include "adc.h" |
mbedalvaro | 0:c19dc1d8b225 | 6 | |
mbedalvaro | 0:c19dc1d8b225 | 7 | #define MBEDFREQUENCY 96000 //frequency of the mBed in KHz |
mbedalvaro | 0:c19dc1d8b225 | 8 | |
mbedalvaro | 0:c19dc1d8b225 | 9 | //#define I_Volts_SAT 5 // this is 5V (the saturation voltage for the APD+LockIn+ADC, being it the arduino (when in normal mode) or the SPI. This saturation voltage could be different for each mode!? |
mbedalvaro | 0:c19dc1d8b225 | 10 | |
mbedalvaro | 0:c19dc1d8b225 | 11 | #define LOCKIN_ADC_PIN p18 //ADC pin : connect to lockin output |
mbedalvaro | 0:c19dc1d8b225 | 12 | #define LOCKIN_LASER_PIN p22 //PWM pin : connect to laser input |
mbedalvaro | 0:c19dc1d8b225 | 13 | #define LOCKIN_REF_PIN p25 //PWM pin : connect to lockin input |
mbedalvaro | 0:c19dc1d8b225 | 14 | // p21 to p25 are used by the PWM timers even if only 2 pin are connected to the circuit |
mbedalvaro | 0:c19dc1d8b225 | 15 | |
mbedalvaro | 0:c19dc1d8b225 | 16 | #define BUFFER_SIZE 3 |
mbedalvaro | 0:c19dc1d8b225 | 17 | |
mbedalvaro | 0:c19dc1d8b225 | 18 | |
mbedalvaro | 0:c19dc1d8b225 | 19 | class Lockin { |
mbedalvaro | 0:c19dc1d8b225 | 20 | public: |
mbedalvaro | 0:c19dc1d8b225 | 21 | // default constructor (untouched!) |
mbedalvaro | 0:c19dc1d8b225 | 22 | // Lockin(); |
mbedalvaro | 0:c19dc1d8b225 | 23 | |
mbedalvaro | 0:c19dc1d8b225 | 24 | // initialization of object modes (could have parameters): |
mbedalvaro | 0:c19dc1d8b225 | 25 | void init(); |
mbedalvaro | 0:c19dc1d8b225 | 26 | |
mbedalvaro | 0:c19dc1d8b225 | 27 | void initPWM(); //setup the laser and reference signal used by the lockin |
mbedalvaro | 0:c19dc1d8b225 | 28 | void setPWMFrequency(float freq); //change the shared period of the pwm signals |
mbedalvaro | 0:c19dc1d8b225 | 29 | void setLaserPhaseShift(float phaseShift); //change the phase shift of the laser (from 0 to 1) |
mbedalvaro | 0:c19dc1d8b225 | 30 | void setLockinPhaseShift(float phaseShift); //change the phase shift of the lock-in (from 0 to 1) |
mbedalvaro | 0:c19dc1d8b225 | 31 | //future works: |
mbedalvaro | 0:c19dc1d8b225 | 32 | //add function to change frequency or offset with a potentiometer for exemple |
mbedalvaro | 0:c19dc1d8b225 | 33 | //or scan the best frequency... |
mbedalvaro | 0:c19dc1d8b225 | 34 | |
mbedalvaro | 0:c19dc1d8b225 | 35 | void setLaserPower(bool power); //change PWM settings to turn on/off the laser |
mbedalvaro | 0:c19dc1d8b225 | 36 | |
mbedalvaro | 0:c19dc1d8b225 | 37 | |
mbedalvaro | 0:c19dc1d8b225 | 38 | float getSmoothValue(); //return the average of the value stored on the buffer |
mbedalvaro | 0:c19dc1d8b225 | 39 | float getLastValue(); //return the last conversion of the ADC |
mbedalvaro | 0:c19dc1d8b225 | 40 | //it is just a begining; we can add more complex method for denoising for exemple |
mbedalvaro | 0:c19dc1d8b225 | 41 | //maybe, needs function to start and stop the lockin |
mbedalvaro | 0:c19dc1d8b225 | 42 | |
mbedalvaro | 0:c19dc1d8b225 | 43 | void clearBuffer(); |
mbedalvaro | 0:c19dc1d8b225 | 44 | |
mbedalvaro | 0:c19dc1d8b225 | 45 | //can be private |
mbedalvaro | 0:c19dc1d8b225 | 46 | //void catchInterupt(uint32_t value); |
mbedalvaro | 0:c19dc1d8b225 | 47 | |
mbedalvaro | 0:c19dc1d8b225 | 48 | //variables |
mbedalvaro | 0:c19dc1d8b225 | 49 | float buffer[BUFFER_SIZE]; |
mbedalvaro | 0:c19dc1d8b225 | 50 | int buffer_pos; |
mbedalvaro | 0:c19dc1d8b225 | 51 | |
mbedalvaro | 0:c19dc1d8b225 | 52 | float refFrequency; // frequency of sensing laser and lock-in (in KHz) |
mbedalvaro | 0:c19dc1d8b225 | 53 | //Phase shift of the pwm signals (from 0 to 1): |
mbedalvaro | 0:c19dc1d8b225 | 54 | //it corresponds to a percentage of the half of a period |
mbedalvaro | 0:c19dc1d8b225 | 55 | //(no phase shift ==> 0% / 90deg phase shift ==> 100%) |
mbedalvaro | 0:c19dc1d8b225 | 56 | float phaseShiftLaser; // phase shift of the sensing laser |
mbedalvaro | 0:c19dc1d8b225 | 57 | float phaseShiftLockin; // phase shift of the lock-in reference |
mbedalvaro | 0:c19dc1d8b225 | 58 | |
mbedalvaro | 0:c19dc1d8b225 | 59 | int refFreq; //frequency of the lockin |
mbedalvaro | 0:c19dc1d8b225 | 60 | int offsetRef; //offset between the laser signal and the lockin reference signal |
mbedalvaro | 0:c19dc1d8b225 | 61 | int halfRefFreq; |
mbedalvaro | 0:c19dc1d8b225 | 62 | |
mbedalvaro | 0:c19dc1d8b225 | 63 | private: |
mbedalvaro | 0:c19dc1d8b225 | 64 | // PWM match register value are saved as private |
mbedalvaro | 0:c19dc1d8b225 | 65 | // to avoid computation when turn on/off for exemple |
mbedalvaro | 0:c19dc1d8b225 | 66 | int _currentMR[6]; |
mbedalvaro | 0:c19dc1d8b225 | 67 | |
mbedalvaro | 0:c19dc1d8b225 | 68 | |
mbedalvaro | 0:c19dc1d8b225 | 69 | }; |
mbedalvaro | 0:c19dc1d8b225 | 70 | |
mbedalvaro | 0:c19dc1d8b225 | 71 | extern Lockin lockin; |
mbedalvaro | 0:c19dc1d8b225 | 72 | |
mbedalvaro | 0:c19dc1d8b225 | 73 | #endif |