Hello everyone,
I have a very confusing system behaviour with my CC2530 ZDK. The basic setup is that one module controls an ultrasonic sensor and periodic (1000 ms) measures the distance in front of the sensor. Than the module sends the result to another module which transceives the data via RS232 to a PC.
I wanted to analyse the time between two transmissions and recorded them for over 1000 seconds. The result is shown in the image below.
As you can see the time interval is about 1000 ms. But in several intervals the time increases rapidly to 12 seconds (!). This happens every 222 measurements (or about 222 seconds). Additonaly the enlargement in the lower image section shows that every (exactly) 60 measurements (or about 60 seconds) the time between two transmission decreases to 950 seconds.
I have no idea why this happens and hope you have any suggestions how to find out what is going wrong. If I have to make a supposition I would say that something inside OSAL is scheduled periodic and fails my 1 sec scheduling.
Edit: The x-axis describes the messages send by the sendor module. The y-axis is the time difference (in miliseconds) between the current message and the last message. So as an example: (10, 1000) --> Message 10 arrived 1000ms after Message 9.
Best regards,
Fabian
