Common Commands
- millis() is unsigned long
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unsigned long previous_time = millis()
uint8_t lowByte(uint16_t value);
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uint16_t value = 0x1234;
uint8_t lower = lowByte(value);
serial_port.println()vsserial_port.write()serial_port.println()adds carriage\r, and\n- it knows the size of the string because a C-string actually ends with a special null terminator (\0). We must add the null ourselves
- what’s the difference between unsigned char and signed char? Any difference in serial comm?
- signed char: -128 to 127, signed char 0 - 255
- So from a serial communication’s perspective, there’s no practical difference. However, to interpret data, yes, and unsigned char makes more sense for ASCII data
Serial Interface
- There might be a permission issue about serial port. Just do:
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sudo chmod a+rw /dev/ttyUSB0
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Also, in Arduino, the timing for decoding might be messed up for serial. Hit the start button for serial to work properl
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numBytesWaiting = SERIAL_GAS_DETECT.available();is the hardware serial interface. returns number of available bytes in the serial receive buffer. -
Teensy sketch uploads could corrupt Serial… One Can do a file checksum on the host linux machine, using
md5sum -
“lockable teensy” is to clone hex dump. (defined in PRJC)
