Mihail Stoyanov
Program to benchmark AnalogIn performance
Fork of
ADC_spikes
by 
Chris Styles
main.cpp@3:4c45267b653d, 2011-12-02 (annotated)
- Committer:
- chris
- Date:
- Fri Dec 02 13:51:06 2011 +0000
- Revision:
- 3:4c45267b653d
- Parent:
- 2:4c61969f2207
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| chris | 3:4c45267b653d | 1 | #include "mbed.h" |
| chris | 3:4c45267b653d | 2 | |
| chris | 3:4c45267b653d | 3 | #define NUM_SAMPLES 500000 // size of sample series |
| chris | 3:4c45267b653d | 4 | #define SAMPLE_BLOCKS 5 |
| chris | 3:4c45267b653d | 5 | |
| chris | 3:4c45267b653d | 6 | Timer t; |
| chris | 3:4c45267b653d | 7 | |
| chris | 3:4c45267b653d | 8 | Serial pc(USBTX,USBRX); |
| chris | 3:4c45267b653d | 9 | |
| chris | 3:4c45267b653d | 10 | AnalogIn ain(p20); |
| chris | 3:4c45267b653d | 11 | |
| chris | 3:4c45267b653d | 12 | // initialise error counters |
| chris | 3:4c45267b653d | 13 | int num_4; |
| chris | 3:4c45267b653d | 14 | int num_8; |
| chris | 3:4c45267b653d | 15 | int num_16; |
| chris | 3:4c45267b653d | 16 | int num_32; |
| chris | 3:4c45267b653d | 17 | int num_64; |
| chris | 3:4c45267b653d | 18 | int num_128; |
| chris | 3:4c45267b653d | 19 | int num_256; |
| chris | 3:4c45267b653d | 20 | int num_512; |
| chris | 3:4c45267b653d | 21 | int num_1024; |
| chris | 3:4c45267b653d | 22 | int num_2048; |
| chris | 3:4c45267b653d | 23 | |
| chris | 3:4c45267b653d | 24 | |
| chris | 3:4c45267b653d | 25 | int main() { |
| chris | 3:4c45267b653d | 26 | |
| chris | 3:4c45267b653d | 27 | pc.baud(115200); |
| chris | 3:4c45267b653d | 28 | |
| chris | 3:4c45267b653d | 29 | int num_samples = 0; |
| chris | 3:4c45267b653d | 30 | |
| chris | 3:4c45267b653d | 31 | num_4 = 0; |
| chris | 3:4c45267b653d | 32 | num_8 = 0; |
| chris | 3:4c45267b653d | 33 | num_16 = 0; |
| chris | 3:4c45267b653d | 34 | num_32 = 0; |
| chris | 3:4c45267b653d | 35 | num_64 = 0; |
| chris | 3:4c45267b653d | 36 | num_128 = 0; |
| chris | 3:4c45267b653d | 37 | num_256 = 0; |
| chris | 3:4c45267b653d | 38 | num_512 = 0; |
| chris | 3:4c45267b653d | 39 | num_1024 = 0; |
| chris | 3:4c45267b653d | 40 | num_2048 = 0; |
| chris | 3:4c45267b653d | 41 | |
| chris | 3:4c45267b653d | 42 | // Take the average over 500,000 samples |
| chris | 3:4c45267b653d | 43 | // This is because the bias to 1.65v has a tolerance |
| chris | 3:4c45267b653d | 44 | float AVERAGE = 0.5; |
| chris | 3:4c45267b653d | 45 | |
| chris | 3:4c45267b653d | 46 | pc.printf("Taking an average over %d samples\n",NUM_SAMPLES); |
| chris | 3:4c45267b653d | 47 | while (num_samples < NUM_SAMPLES) { |
| chris | 3:4c45267b653d | 48 | float r = ain.read(); |
| chris | 3:4c45267b653d | 49 | |
| chris | 3:4c45267b653d | 50 | if ((r > 0.45) && (r < 0.55)) { |
| chris | 3:4c45267b653d | 51 | AVERAGE += r; |
| chris | 3:4c45267b653d | 52 | num_samples++; |
| chris | 3:4c45267b653d | 53 | } |
| chris | 3:4c45267b653d | 54 | } |
| chris | 3:4c45267b653d | 55 | |
| chris | 3:4c45267b653d | 56 | AVERAGE /= NUM_SAMPLES; |
| chris | 3:4c45267b653d | 57 | |
| chris | 3:4c45267b653d | 58 | num_samples = 0; |
| chris | 3:4c45267b653d | 59 | pc.printf("Average = %f\n",AVERAGE); |
| chris | 3:4c45267b653d | 60 | |
| chris | 3:4c45267b653d | 61 | |
| chris | 3:4c45267b653d | 62 | // Now start sampling series of 500,000 |
| chris | 3:4c45267b653d | 63 | // acculumating the errors seen in each range |
| chris | 3:4c45267b653d | 64 | pc.printf("Profiling %d samples\n",SAMPLE_BLOCKS*NUM_SAMPLES); |
| chris | 3:4c45267b653d | 65 | for (int j=0; j < SAMPLE_BLOCKS ; j++) { |
| chris | 3:4c45267b653d | 66 | |
| chris | 3:4c45267b653d | 67 | t.reset(); |
| chris | 3:4c45267b653d | 68 | t.start(); |
| chris | 3:4c45267b653d | 69 | |
| chris | 3:4c45267b653d | 70 | for (int i = 0; i < NUM_SAMPLES ; i++) { |
| chris | 3:4c45267b653d | 71 | float a = ain.read(); |
| chris | 3:4c45267b653d | 72 | |
| chris | 3:4c45267b653d | 73 | if (a > (AVERAGE + 0.5000)) { |
| chris | 3:4c45267b653d | 74 | num_2048++; // > 2048 lsb |
| chris | 3:4c45267b653d | 75 | } else if (a > (AVERAGE + 0.2500)) { |
| chris | 3:4c45267b653d | 76 | num_1024++; // > 1024 lsb |
| chris | 3:4c45267b653d | 77 | } else if (a > (AVERAGE + 0.0625)) { |
| chris | 3:4c45267b653d | 78 | num_512++; // > 512 lsb |
| chris | 3:4c45267b653d | 79 | } else if (a > (AVERAGE + 0.0312)) { |
| chris | 3:4c45267b653d | 80 | num_256++; // > 256 lsb |
| chris | 3:4c45267b653d | 81 | } else if (a > (AVERAGE + 0.0312)) { |
| chris | 3:4c45267b653d | 82 | num_128++; // > 128 lsb |
| chris | 3:4c45267b653d | 83 | } else if (a > (AVERAGE + 0.0156)) { |
| chris | 3:4c45267b653d | 84 | num_64++; // > 64 lsb |
| chris | 3:4c45267b653d | 85 | } else if (a > (AVERAGE + 0.0078)) { |
| chris | 3:4c45267b653d | 86 | num_32++; // > 32 lsb |
| chris | 3:4c45267b653d | 87 | } else if (a > (AVERAGE + 0.0039)) { |
| chris | 3:4c45267b653d | 88 | num_16++; // > 16 lsb |
| chris | 3:4c45267b653d | 89 | } else if (a > (AVERAGE + 0.0019)) { |
| chris | 3:4c45267b653d | 90 | num_8++; // > 8 lsb |
| chris | 3:4c45267b653d | 91 | } else if (a > (AVERAGE + 0.0009)) { |
| chris | 3:4c45267b653d | 92 | num_4++; // > 8 lsb |
| chris | 3:4c45267b653d | 93 | } |
| chris | 3:4c45267b653d | 94 | |
| chris | 3:4c45267b653d | 95 | num_samples++; |
| chris | 3:4c45267b653d | 96 | } |
| chris | 3:4c45267b653d | 97 | t.stop(); |
| chris | 3:4c45267b653d | 98 | |
| chris | 3:4c45267b653d | 99 | // Every 500,000 print the results |
| chris | 3:4c45267b653d | 100 | pc.printf("%d\t",num_samples); |
| chris | 3:4c45267b653d | 101 | pc.printf("%d\t",num_4); |
| chris | 3:4c45267b653d | 102 | pc.printf("%d\t",num_8); |
| chris | 3:4c45267b653d | 103 | pc.printf("%d\t",num_16); |
| chris | 3:4c45267b653d | 104 | pc.printf("%d\t",num_32); |
| chris | 3:4c45267b653d | 105 | pc.printf("%d\t",num_64); |
| chris | 3:4c45267b653d | 106 | pc.printf("%d\t",num_128); |
| chris | 3:4c45267b653d | 107 | pc.printf("%d\t",num_256); |
| chris | 3:4c45267b653d | 108 | pc.printf("%d\t",num_512); |
| chris | 3:4c45267b653d | 109 | pc.printf("%d\t",num_1024); |
| chris | 3:4c45267b653d | 110 | pc.printf("%d\t",num_2048); |
| chris | 3:4c45267b653d | 111 | pc.printf("%f\n",t.read()); |
| chris | 3:4c45267b653d | 112 | } |
| chris | 3:4c45267b653d | 113 | |
| chris | 3:4c45267b653d | 114 | pc.printf("==== Test Complete ====\n"); |
| chris | 3:4c45267b653d | 115 | } |