如何停止读数流量计

嗨，我一直在网上搜索关于这个话题的帮助。我用PIC24为一个高级项目，我需要一些帮助，如何使用计时器来计算流过桶线的液体量。我在PIC和NFC读卡器之间有一个UART连接。我认为这样做的方法是：1。UART从代码读取器中断2。卡ID检查，看看用户是否有“学分”和超过21.3岁。如果它们有通路，则用一个阀门来打开桶上的管道。4。在同一中断中，计数液体流量计的脉冲数。5。一旦流程停止5秒，更新桶体积变量和用户液体变量。问题是步骤4。我很困惑如何停止读数流量计，或如何获得脉冲数量后，用户拉动龙头把手。任何见解或建议是受欢迎的。



      以下为原文

    Hi,

I've been searching the web for help on this topic.  I am using a PIC24 for a senior project, and I need some help as to how to use a timer to calculate the amount of liquid flowing through a keg line.

I have a UART connection made between the PIC and a NFC card reader.  The way I am thinking this should work is:
1. UART interrupt from Code reader
2. Card ID is checked to see if user has "credits" and over the age of 21.
3. If they have access, a valve is wired up to open the line on the keg.
4. INSIDE of this same interrupt, count the number of pulses from liquid flow meter.
5. Once the flow has stopped for >5 seconds, update keg volume variable and user liquid variable.

The problem is with step 4.  I'm confused as to how to stop the reading of the flow meter, or how to get the number of pulses after the user pulls the tap handle.

Any insight or suggestions are welcome.