I am trying to read a flowing 16 byte long stream of data from a solar panel controller from which I can extract charge voltages and current from various bytes in the packet. My difficulty at the moment is how to identify the start of the packet. The first 2 bytes which are always the same are 0xAA …

Hello Post some data sets in HEX from data logging.

Here's some typical received hex data: AA, 1A, FC, 04, 32, 07, 1A, 00, 00, 00, 00, 14, 22, 00, 09, F2 AA, 1A, FC, 04, 26, 07, 1A, 00, 00, 00, 00, 14, 22, 00, 09, E6 AA, 1A, FA, 04, 78, 07, 19, 00, 00, 00, 00, 14, 22, 00, 09, BD

[image] anon73444976: Why not write it as a single state machine? If I understood what a single state machine was I possibly would. Time for some more research. Incidentally, I started a new thread to try and focus on identifying 2 start marker bytes.

Are the data packets you posted in #4 the only data packets sent from the solar panel controller, or are there other ones? Is the serial link really operating at 1000 baud? Is there a gap between each message - that can also be used to detect the start of a new message.

Uncompiled, and therefore untested enum RX_STATE {WAIT_PREAMBLE, HANDLE_PAYLOAD, CHECK_MESSAGE} rxState; static const uint8_t preamble [] {0xAA, 0x1A}; static const uint8_t preambleLength = sizeof (preamble); static const uint8_t messageSize = 15; // The length of the message excluding the checksu…

[image] keith-i: I am trying to read a flowing 16 byte long stream of data from a solar panel controller If you are receiving the bytes (natural binary not ASCII coded) of Post-4 over Software UART Port (SUART Port), then the following could be a solution to receive the 16-byte wide frame of …

[image] markd833: Are the data packets you posted in #4 the only data packets sent from the solar panel controller, or are there other ones? Is the serial link really operating at 1000 baud? Is there a gap between each message - that can also be used to detect the start of a new message. Ye…

[image] GolamMostafa: If you are receiving the bytes (natural binary not ASCII coded) of Post-4 over Software UART Port (SUART Port), then the following could be a solution to receive the 16-byte wide frame of which only 14-byte are saved. Thanks for your help. I am using a Teensy 3.2 so it i…

[image] anon73444976: Uncompiled, and therefore untested Thank you very much. I will give that a spin.

Confusion reading hex stream with 2 start markers

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anon73444976 March 20, 2022, 12:55pm 2

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Why not write it as a single state machine?

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Confusion reading hex stream with 2 start markers

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