Kenji Arai / freq_counter

Frequency Counter Library. Only for mbed LPC1768, mbed LPC1114FN28, Nucleo-F401 and Nucleo-F411. No way to change pin assign.

Dependents:   Frequency_Counter Frequency_wind_speed_measure Frequency_counter_wind_speed

Please refer following page.
http://developer.mbed.org/users/kenjiArai/notebook/simple-frequency-counter/

freq_counter.cpp@0:83661d0d09c0, 2014-10-19 (annotated)

Committer:
kenjiArai
Date:
Sun Oct 19 06:44:51 2014 +0000
Revision:
0:83661d0d09c0
Child:
1:fd2e1c853ab6
Frequency Counter Lib. based on mio/5MHzOSC program

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kenjiArai 0:83661d0d09c0 1 /*
kenjiArai 0:83661d0d09c0 2 * mbed Library program
kenjiArai 0:83661d0d09c0 3 * Frequency Counter Hardware relataed program
kenjiArai 0:83661d0d09c0 4 *
kenjiArai 0:83661d0d09c0 5 * Copyright (c) 2014 Kenji Arai / JH1PJL
kenjiArai 0:83661d0d09c0 6 * http://www.page.sannet.ne.jp/kenjia/index.html
kenjiArai 0:83661d0d09c0 7 * http://mbed.org/users/kenjiArai/
kenjiArai 0:83661d0d09c0 8 * Addition and Modification
kenjiArai 0:83661d0d09c0 9 * started: October 18th, 2014
kenjiArai 0:83661d0d09c0 10 * Revised: October 19th, 2014
kenjiArai 0:83661d0d09c0 11 *
kenjiArai 0:83661d0d09c0 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
kenjiArai 0:83661d0d09c0 13 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
kenjiArai 0:83661d0d09c0 14 * AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
kenjiArai 0:83661d0d09c0 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
kenjiArai 0:83661d0d09c0 16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
kenjiArai 0:83661d0d09c0 17 */
kenjiArai 0:83661d0d09c0 18
kenjiArai 0:83661d0d09c0 19 #include "mbed.h"
kenjiArai 0:83661d0d09c0 20 #include "freq_counter.h"
kenjiArai 0:83661d0d09c0 21
kenjiArai 0:83661d0d09c0 22 F_COUNTER::F_COUNTER(PinName f_in): _pin(f_in)
kenjiArai 0:83661d0d09c0 23 {
kenjiArai 0:83661d0d09c0 24 initialize();
kenjiArai 0:83661d0d09c0 25 }
kenjiArai 0:83661d0d09c0 26
kenjiArai 0:83661d0d09c0 27 void F_COUNTER::initialize(void)
kenjiArai 0:83661d0d09c0 28 {
kenjiArai 0:83661d0d09c0 29 #if defined(TARGET_LPC1768)
kenjiArai 0:83661d0d09c0 30 LPC_SC->PCONP |= 1 << 22; // 1)Power up TimerCounter3 (bit23)
kenjiArai 0:83661d0d09c0 31 LPC_PINCON->PINSEL0 |= 3 << 8; // 2)Set P0[23] to CAP3[0]
kenjiArai 0:83661d0d09c0 32 LPC_TIM2->TCR = 2; // 3)Counter Reset (bit1<=1,bit0<=0)
kenjiArai 0:83661d0d09c0 33 LPC_TIM2->CTCR = 1; // 4)Count on riging edge Cap3[0]
kenjiArai 0:83661d0d09c0 34 LPC_TIM2->CCR = 0; // 5)Input Capture Disabled
kenjiArai 0:83661d0d09c0 35 LPC_TIM2->TCR = 1; // 6)Counter Start (bit1<=0,bit0<=1)
kenjiArai 0:83661d0d09c0 36 #else
kenjiArai 0:83661d0d09c0 37 #error "No support for this CPU"
kenjiArai 0:83661d0d09c0 38 #endif
kenjiArai 0:83661d0d09c0 39 }
kenjiArai 0:83661d0d09c0 40
kenjiArai 0:83661d0d09c0 41 uint32_t F_COUNTER::read_frequency(float gate_time)
kenjiArai 0:83661d0d09c0 42 {
kenjiArai 0:83661d0d09c0 43 #if defined(TARGET_LPC1768)
kenjiArai 0:83661d0d09c0 44 LPC_TIM2->TCR = 2; // Reset the counter (bit1<=1,bit0<=0)
kenjiArai 0:83661d0d09c0 45 LPC_TIM2->TCR = 1; // UnReset counter (bit1<=0,bit0<=1)
kenjiArai 0:83661d0d09c0 46 wait(gate_time); // Gate time for count
kenjiArai 0:83661d0d09c0 47 freq = LPC_TIM2->TC;
kenjiArai 0:83661d0d09c0 48 return freq;
kenjiArai 0:83661d0d09c0 49 #else
kenjiArai 0:83661d0d09c0 50 #error "No support for this CPU"
kenjiArai 0:83661d0d09c0 51 #endif
kenjiArai 0:83661d0d09c0 52 }
kenjiArai 0:83661d0d09c0 53
kenjiArai 0:83661d0d09c0 54 #if 0
kenjiArai 0:83661d0d09c0 55 //-------------------------------------------------------------------------------------------------
kenjiArai 0:83661d0d09c0 56 // Reference program
kenjiArai 0:83661d0d09c0 57 //-------------------------------------------------------------------------------------------------
kenjiArai 0:83661d0d09c0 58
kenjiArai 0:83661d0d09c0 59 // 5MHzOSC
kenjiArai 0:83661d0d09c0 60 // http://developer.mbed.org/users/mio/code/5MHzOSC/
kenjiArai 0:83661d0d09c0 61 // by fuyono sakura
kenjiArai 0:83661d0d09c0 62 // http://developer.mbed.org/users/mio/
kenjiArai 0:83661d0d09c0 63
kenjiArai 0:83661d0d09c0 64 //
kenjiArai 0:83661d0d09c0 65 // CLOCK OUT to PWM1[6] Sample with Freq Counter using Cap2.0
kenjiArai 0:83661d0d09c0 66 // For LPC1768-mbed
kenjiArai 0:83661d0d09c0 67 //
kenjiArai 0:83661d0d09c0 68 // Reference: 5MHz Clock Out Code and Comment - http://mbed.org/forum/mbed/topic/733/
kenjiArai 0:83661d0d09c0 69 //
kenjiArai 0:83661d0d09c0 70 // !! To Self Measurement Output Clock, Connect p21 <-> p30 with jumper wire.
kenjiArai 0:83661d0d09c0 71 // 2013.6.18 : Wrong comment about MR6 and Duty fix.
kenjiArai 0:83661d0d09c0 72 //
kenjiArai 0:83661d0d09c0 73
kenjiArai 0:83661d0d09c0 74 #include "mbed.h"
kenjiArai 0:83661d0d09c0 75
kenjiArai 0:83661d0d09c0 76 PwmOut fmclck(p21); // for RESERVE pin21 as PWM1[6]
kenjiArai 0:83661d0d09c0 77 DigitalIn clkin(p30); // for RESERVE pin30 as CAP2[0]
kenjiArai 0:83661d0d09c0 78
kenjiArai 0:83661d0d09c0 79 // Reset Counter and Count Start
kenjiArai 0:83661d0d09c0 80 void P30_RESET_CTR(void)
kenjiArai 0:83661d0d09c0 81 {
kenjiArai 0:83661d0d09c0 82 LPC_TIM2->TCR = 2; // Reset the counter (bit1<=1,bit0<=0)
kenjiArai 0:83661d0d09c0 83 LPC_TIM2->TCR = 1; // UnReset counter (bit1<=0,bit0<=1)
kenjiArai 0:83661d0d09c0 84 }
kenjiArai 0:83661d0d09c0 85
kenjiArai 0:83661d0d09c0 86 // Get Counter Value
kenjiArai 0:83661d0d09c0 87 int P30_GET_CTR(void)
kenjiArai 0:83661d0d09c0 88 {
kenjiArai 0:83661d0d09c0 89 return LPC_TIM2->TC; // Read the counter value
kenjiArai 0:83661d0d09c0 90 }
kenjiArai 0:83661d0d09c0 91
kenjiArai 0:83661d0d09c0 92 // Setting p30 to Cap2.0
kenjiArai 0:83661d0d09c0 93 void P30_INIT_CTR(void)
kenjiArai 0:83661d0d09c0 94 {
kenjiArai 0:83661d0d09c0 95 LPC_SC->PCONP |= 1 << 22; // 1)Power up TimerCounter2 (bit22)
kenjiArai 0:83661d0d09c0 96 LPC_PINCON->PINSEL0 |= 3 << 8; // 2)Set P0[4] to CAP2[0]
kenjiArai 0:83661d0d09c0 97 LPC_TIM2->TCR = 2; // 3)Counter Reset (bit1<=1,bit0<=0)
kenjiArai 0:83661d0d09c0 98 LPC_TIM2->CTCR = 1; // 4)Count on riging edge Cap2[0]
kenjiArai 0:83661d0d09c0 99 LPC_TIM2->CCR = 0; // 5)Input Capture Disabled
kenjiArai 0:83661d0d09c0 100 LPC_TIM2->TCR = 1; // 6)Counter Start (bit1<=0,bit0<=1)
kenjiArai 0:83661d0d09c0 101 }
kenjiArai 0:83661d0d09c0 102
kenjiArai 0:83661d0d09c0 103 // Clock Output From pin21(PWM6)
kenjiArai 0:83661d0d09c0 104 // Set Clock Freq with div.
kenjiArai 0:83661d0d09c0 105 // if mbed is running at 96MHz, div is set 96 to Get 1MHz.
kenjiArai 0:83661d0d09c0 106 void PWM6_SETCLK(int div)
kenjiArai 0:83661d0d09c0 107 {
kenjiArai 0:83661d0d09c0 108 LPC_PWM1->TCR = (1 << 1); // 1)Reset counter, disable PWM
kenjiArai 0:83661d0d09c0 109 LPC_SC->PCLKSEL0 &= ~(0x3 << 12);
kenjiArai 0:83661d0d09c0 110 LPC_SC->PCLKSEL0 |= (1 << 12); // 2)Set peripheral clock divider to /1, i.e. system clock
kenjiArai 0:83661d0d09c0 111 LPC_PWM1->MR0 = div - 1; // 3)Match Register 0 is shared period counter for all PWM1
kenjiArai 0:83661d0d09c0 112 LPC_PWM1->MR6 = (div + 1)>> 1; //
kenjiArai 0:83661d0d09c0 113 LPC_PWM1->LER |= 1; // 4)Start updating at next period start
kenjiArai 0:83661d0d09c0 114 LPC_PWM1->TCR = (1 << 0) || (1 << 3); // 5)Enable counter and PWM
kenjiArai 0:83661d0d09c0 115 }
kenjiArai 0:83661d0d09c0 116
kenjiArai 0:83661d0d09c0 117 int main()
kenjiArai 0:83661d0d09c0 118 {
kenjiArai 0:83661d0d09c0 119 PWM6_SETCLK(19) ; // Outout mbed's "PWM6" pin to 96MHZ/19 = 5.052MHz (Approx)
kenjiArai 0:83661d0d09c0 120 // PWM6_SETCLK(96) ; // Outout mbed's "PWM6" pin to 96MHZ/96 = 1.000MHz (Approx)
kenjiArai 0:83661d0d09c0 121 P30_INIT_CTR();
kenjiArai 0:83661d0d09c0 122 while(1) {
kenjiArai 0:83661d0d09c0 123 P30_RESET_CTR();
kenjiArai 0:83661d0d09c0 124 wait(1.0); // Gate time for count
kenjiArai 0:83661d0d09c0 125 printf("pin30 Freq = %d (Hz)\r\n",P30_GET_CTR());
kenjiArai 0:83661d0d09c0 126 }
kenjiArai 0:83661d0d09c0 127 }
kenjiArai 0:83661d0d09c0 128
kenjiArai 0:83661d0d09c0 129 #endif