Minimal bit-bang send serial. 115200 baud for 1/8/16 MHz ATtiny clock.
Available as Arduino library "ATtinySerialOut".
- Perfect for debugging purposes.
- Provides Serial.print / println functions for easy software porting.
- Code size is only 76 bytes@38400 baud or 196 bytes@115200 baud (including first call).
- Provides additional fast printHex() and printlnHex() functions.
- Default TX pin is PIN_PB2 on an ATtiny85.
- Currently support for: ATtiny13(A), ATtiny25, ATtiny45, ATtiny85, ATtiny24, ATtiny44, ATtiny84, ATtiny87, ATtiny167 and ATtiny88.
void print(const __FlashStringHelper *aStringPtr);
void print(const char *aStringPtr);
void print(char aChar);
void print(uint8_t aByte, uint8_t aBase = 10);
void print(int16_t, uint8_t aBase = 10);
void print(uint16_t aInteger, uint8_t aBase = 10);
void print(uint32_t aLong, uint8_t aBase = 10);
void print(uint32_t aLong, uint8_t aBase = 10);
void print(double aFloat, uint8_t aDigits = 2);
void printHex(uint8_t aByte); // with 0x prefix
void println(const __FlashStringHelper *aStringPtr);
void println(char aChar);
void println(uint8_t aByte, uint8_t aBase = 10);
void println(int16_t aInteger, uint8_t aBase = 10);
void println(uint16_t aInteger, uint8_t aBase = 10);
void println(int32_t aLong, uint8_t aBase = 10);
void println(uint32_t aLong, uint8_t aBase = 10);
void println(double aFloat, uint8_t aDigits = 2);
void println(void);#include <Arduino.h>
#if defined(__AVR_ATtiny87__) || defined(__AVR_ATtiny167__)
#define TX_PIN PIN_PA1 // (package pin 2 / TXD on Tiny167) - can use one of PIN_PA0 to PIN_PA7 here
#else
#define TX_PIN PIN_PB2 // (package pin 7 on Tiny85) - can use one of PIN_PB0 to PIN_PB4 (+PIN_PB5) here
#endif
void setup(void) {
initTXPin();
Serial.println(F("START " __FILE__ " from " __DATE__ "\r\nUsing library version " VERSION_ATTINY_SERIAL_OUT));
writeString("OSCCAL=");
writeUnsignedByteHexWithPrefix(OSCCAL);
}
void loop() {
}
In order to support compile options more easily,
the line #include <ATtinySerialOut.h> must be changed to #include <ATtinySerialOut.hpp>
in your main program (aka *.ino file with setup() and loop()).
In all other files you must use #include <ATtinySerialOut.h>, to prevent multiple definitions linker errors:
If you forget to include ATtinySerialOut.hpp, you will see errors like ATtinySerialOutExample.cpp:38: undefined reference to initTXPin()`.
To customize the library to different requirements, there are some compile options / macros available.
These macros must be defined in your program before the line #include <TinySerialOut.hpp> to take effect.
Modify them by enabling / disabling them, or change the values if applicable.
| Name | Default value | Description |
|---|---|---|
TX_PIN |
PIN_PB2 (PIN_PA1 for ATtiny87/167) | The pin to use for transmitting bit bang serial. These pin names are valid for ATTinyCore and may be different in other cores. |
TINY_SERIAL_DO_NOT_USE_115200BAUD |
disabled | To force using other baud rates. The rates are 38400 baud at 1 MHz (which has smaller code size) or 230400 baud at 8/16 MHz. |
TINY_SERIAL_INHERIT_FROM_PRINT |
disabled | If defined, you can use this class as a replacement for standard Serial as a print class e.g. for functions like void prinInfo(Print *aSerial). Increases program size. |
This example issues an alarm if the chip sensor detect a falling teperarure and is fully documented here
Please use the new Digistump core. Since version 1.2.0, the library is no longer compatible with the old cores supplied by digistump.
Reason: Another class, e.g. ATTinyCore class TwoWire : public Stream uses the Print class or a Print method, but Print is normally redefined by ATtinySerialOut.
You must define TINY_SERIAL_INHERIT_FROM_PRINT before including ATtinySerialOut.hpp, to avoid this error.
- Added operator bool() for "if(!Serial)..."
- Untested support of ATtiny13
- Support of all ports of ATtiny88 using ATTinyCore numbering scheme.
- Usage of ATTinyCore pin numbering also for ATtiny167.
- Usage of ATTinyCore pin numbering scheme e.g. PIN_PB2 and therefore removed
USE_PORTB_FOR_TX_PIN.
- Adjusted macro for MH-ET LIVE Core.
- Added compile guard.
- Added
USE_PORTB_FOR_TX_PINto allow TX pin on port B for ATtiny87/167. - Improved #if guard for instance naming.
- Renamed ATtinySerialOut.cpp to ATtinySerialOut.hpp => TX pin can be defined in main program.
- Added symbol
TINY_SERIAL_INHERIT_FROM_PRINT- if defined, you can use this class as a replacement for standard Serial as a print class.
- Cloned ATtinySerialOut.cpp as ATtinySerialOut.hpp for direct include.
- Added ATtiny88 support.
- Added ATtinyX4 support.
- Removed workaround
#define __FlashStringHelper fstr_tfor old Digispark core < 1.6.8 in order to work with core >= 1.7.0. - Added ATtiny167 support.
- Moved functions from h to cpp file.
- Removed symbol
TINY_SERIAL_INHERIT_FROM_PRINTand replaced by macro#define Print TinySerialOut - Changed
inttoint16_tandlongtoint32_t. - Use
utoa()andultoa()foruint16_tanduint32_t.
- Added function
writeCRLF()
- Symbol TINY_SERIAL_INHERIT_FROM_PRINT - if defined, you can use this class as a replacement for standard Serial as a print class.
- Improved all ...Hex() functions.
- Define FlashStringHelper for digispark.
- Changed label
looptotxloopinwrite1Start8Data1StopNoParity()for 38400 baud.
- OpenWindowAlarm example updated.
printHex()now using capital letters.- Improved OpenWindowAlarm example.
- Renamed example to be consistent.
Initial Arduino library version.
C version of serial code is included for better understanding, but assembler version is used. This is because for the C code the timing depends on compiler optimisation switches. You should get the right timing if you compile the C code it with Arduino standard settings or:
avr-g++ -I"C:\arduino\hardware\arduino\avr\cores\arduino" -I"C:\arduino\hardware\arduino\avr\variants\standard" -c -g -w -Os -ffunction-sections -fdata-sections -mmcu=attiny85 -DF_CPU=1000000UL -MMD -o "TinySerialOut.o" "TinySerialOut.cpp"
