c - One wire protocol in SIM800 through bit banging -
is possible implement one wire protocol
in sim800 through bit banging
? time required change direction of pin (as input or output) 1.5 microsecond , time required change state of pin (as low or high) 1.5 microsecond.
the dallas/maxim 1-wire(tm) protocol self-clocking; deliberately designed make easy implement in way. using hardware timer idea - removing deal of software overhead, low-precision rc oscillator accurate enough.
1-wire(tm) self-clocking assume timings suggest minimum timings, not required timing; protocol has wide tolerances actual bit timing, , inter-bit timing merely requires line high >1us, may length. needs long enough able detect definite edge - on input-capture timer or edge triggered interrupt example - software poll line, if application needs other work done @ same time, 1us pulse may missed.
it not clear me definition of timings suggest are, if refer duration of edge, 1.5us suggest not software issue - down slew-rate of i/o pin largely function of line characteristics. short distance communication, you'd have mess hardware design switching slow.
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