;|http://www.pICavr.com-------------------------------------------------
;| 2000
;|------------------------------------------------------------------------|
;| 7LED频率计 共计 35 MHz. The decimal 小数点 |
;| point is after MHz digit, but CAN be set at any position. Two dots can |
;| be set too (timing formula will change!). |
;| |
;| 功耗: 2.5V/9mA, 3V/13mA, 5V/35mA. |
;| |
;| 硬件: |
;| : PIC 16F84 |
;| 4051 (BCD -> 1 of 8 decoder) |
;| 8个 NPN 三极管, |
;| 7LED (共阴), |
;| some resistors, caPACitors and 2 switching diodes |
;| |
;| Note: |
;| "Calculator display" means (say) 7 digit LED multiplexed display. |
;| Both common cathode and common anode can be used. SOFtware is written |
;| for both common cathode and common anode display. For common anode |
;| displays it requires very slight software (uncomment what is commented |
;| and comment what isn’t...;-) and hardware modification (switching |
;| transistors are PNP instead NPN, ther EMIters are connected with +5V |
;| and also PIN No.3 of 4051 should be grounded). |
;| |
;| PIC is used as 3 byte counter. If it counts 0.1 s maximum measured |
;| Frequency is FF FF FF, e. g. 167.77215 MHz (theoretically). |
;| |
;| In reality the maximum measured frequency will not exceed 50 MHz |
;| what is maximum input frequency of PIC precounter. But real one is |
;| around 27 MHz and with 1/6 of 74HC14 (Schmitt trigger) up to 38 MHz. |
;| | | |
;| +-+ +-+ |
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本文关键字：暂无联系方式PIC单片机，单片机-工控设备 - PIC单片机
