Satoru Yoshida
test interruptIn feature with 555 timer
Dependencies: ClockControl PowerControl mbed
Fork of
Frequency_counter
by 
Satoru Yoshida
Test interruptIn function with using LMC555 timer IC
LPC 1768 自身が持つタイマー割り込み機能を使わずに、 あえて外部のタイマー IC 555 からの信号で周期的に割り込みするテスト。
下記の回路例では、555 の output 端子が 約 10 秒周期のうち、0.3 秒間 Low になるはず。 ただし、コンデンサーおよび抵抗の誤差の影響があり、実測値は約７秒周期
C を 47μ から 330 μ に変えると約１分前後で周期的に割り込みがかかります。
なるべく配線が交差しないように部品配置してみた例
main.cpp@8:cb966096a916, 2014-05-11 (annotated)
- Committer:
- strysd
- Date:
- Sun May 11 07:29:02 2014 +0000
- Revision:
- 8:cb966096a916
- Parent:
- 7:42e7f18361c8
test interrupt by 555
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| Neel | 0:c5bcf643a8b1 | 1 | #include "mbed.h" |
| strysd | 8:cb966096a916 | 2 | #include "PowerControl/EthernetPowerControl.h" |
| strysd | 8:cb966096a916 | 3 | #include "ClockControl/ClockControl.h" |
| strysd | 1:e2034bcdb101 | 4 | |
| strysd | 8:cb966096a916 | 5 | InterruptIn in(p8); //Connect from output of 555 |
| strysd | 7:42e7f18361c8 | 6 | DigitalOut led1(LED1);//running 555 |
| Neel | 0:c5bcf643a8b1 | 7 | |
| strysd | 8:cb966096a916 | 8 | /* stop USB Interface */ |
| strysd | 8:cb966096a916 | 9 | #define USR_POWERDOWN (0x104) |
| strysd | 8:cb966096a916 | 10 | int semihost_powerdown() { |
| strysd | 8:cb966096a916 | 11 | uint32_t arg; |
| strysd | 8:cb966096a916 | 12 | return __semihost(USR_POWERDOWN, &arg); |
| strysd | 8:cb966096a916 | 13 | } |
| Neel | 0:c5bcf643a8b1 | 14 | |
| Neel | 0:c5bcf643a8b1 | 15 | void flip(void) |
| Neel | 0:c5bcf643a8b1 | 16 | { |
| strysd | 8:cb966096a916 | 17 | led1 = !led1; |
| Neel | 0:c5bcf643a8b1 | 18 | } |
| Neel | 0:c5bcf643a8b1 | 19 | |
| Neel | 0:c5bcf643a8b1 | 20 | int main() { |
| strysd | 8:cb966096a916 | 21 | led1 = 0; |
| strysd | 1:e2034bcdb101 | 22 | |
| strysd | 8:cb966096a916 | 23 | setSystemFrequency(0x3, 0x1, 6, 1);//clock down from 96MHz to 48MHz |
| strysd | 8:cb966096a916 | 24 | |
| strysd | 8:cb966096a916 | 25 | semihost_powerdown();//Stop also USB Interface |
| strysd | 8:cb966096a916 | 26 | PHY_PowerDown();//net |
| strysd | 5:9be3080ca8ba | 27 | |
| strysd | 8:cb966096a916 | 28 | // Set up the interrupt |
| strysd | 8:cb966096a916 | 29 | in.mode(PullNone); |
| strysd | 8:cb966096a916 | 30 | in.rise(&flip); |
| strysd | 8:cb966096a916 | 31 | |
| strysd | 8:cb966096a916 | 32 | while(1){ |
| strysd | 8:cb966096a916 | 33 | wait(1); |
| Neel | 0:c5bcf643a8b1 | 34 | } |
| strysd | 8:cb966096a916 | 35 | |
| Neel | 0:c5bcf643a8b1 | 36 | } |