OSAL is mainly a mechanism,a mechanism for allocating resources among tasks,thus forming a simple multi-tasking operating system.First , OSAL initializes the system, including software system initiali
My board uses cortex m3, and now the transmitter can send data. I have checked the DR port and found that there is a high and low level switch, but no signal can be received at the receiver. The DR po
The MQTT protocol is built on top of the TCP protocol, just like a car chassis can run with four tires, but if you want everyone to drive more comfortably, we still have to add a shell to the chassis.