MCU-I2C-Expander

The main idea of this project is to use small microcontrollers like Atmega328, Attiny88, ... to extend functionality (e.g. watchdog timer, volatile memory, RAM, I/O pins, PWM, ...) of main master microcontrollers connected via I2C bus.

ATTENTION: The platformio project is initially configured for atmega328 microcontrollers with clocking from the built-in quartz resonator with the ability to work in 3.3v mode.

ATTENTION: All project settings are scattered across header files. Default i2c address is 8. Please note that the project uses a separate interrupt pin. Note that the byte order must match on both devices.

Features

Commands supported by the controller, writing to commands is indicated by a leading character ~ + command code + required bytes for the command + interrupt (if specified in the input).

	Feature	Code (u8)	RecvBytes (count)	RecvInt (exp(+)/ignore(-))	SendBytes(count)	SendInt(exp(+)/ignore(-))
	SysRestart	10	0	-	0	!+
	SysPinsRestart	11	0	-	0	+
	LED_BUILTIN_ON	20	0	-	0	+
	LED_BUILTIN_OFF	21	0	-	0	+
	Read_ADC_Temperature	30
	AnalogRead	31	1	-	2	+
	INTERRUPT_ON	40	0	-	0	+
	INTERRUPT_OFF	41	0	-	0	-
	PinModeOutput	50	1	-	0	+
	PinModeInput	51	1	-	0	+
	PinModeInputPullup	52	1	-	0	+
	PinTimerSetFreq	55	2	-	0	+
	DigitalWriteHigh	60	1	-	0	+
	DigitalWriteLow	61	1	-	0	+
	AnalogWrite	70	2	-	0	+
	AnalogWrite16Bit	71	3	-	0	+
	AutoSleepAdcOn	80	0	-	0	+
	AutoSleepAdcOff	81	0	-	0	+
	ButtonInterruptOff	90	1	-	0	+
	ButtonRegRising	91	1	-	0	+
	ButtonRegChange	92	1	-	0	+
	ButtonRegFalling	93	1	-	0	+
	ClearButtons	94	0	-	0	+
	ReadButtons	95	0	-	0 or array (num+count)	+
	GetCountButtons	96	1	-	0	+
	GetSizeMem	100	0	-	2	+
	FlushMem	101	0	-	0	+
	SetMem	102	2	-	0	+
	GetMem	103	1	-	1	+
	SetMem16BitAdress	104	3	-	0	+
	GetMem16BitAdress	105	2	-	1	+
	I2CSetSpeed	110	4	-	0	+
	DefCPU_PINSLEEP_Ignore	120	0	-	0	+
	DefCPU_PINSLEEP_Idle	121	0	-	0	+
	DefCPU_PINSLEEP_ADC	122	0	-	0	+
	DefCPU_PINSLEEP_PowerDown	122	0	-	0	+
	CPU_SLEEP_ON	125	0	-	0	+
	CPU_SLEEP_OFF	126	0	-	0	+
	EGetSizeMem	130	0	-	2	+
	EFlushMem	131	0	-	0	+
	ESetMem	132	3	-	0	+
	EGetMem	133	2	-	1	+
	GetMillis	140	4	-	0	+
	DallasWireIni	150	2	-	1	+
	DallasWireAllLength	151	0	-	1	+
	DallasWireInitLength	152	1	-	0	+
	DallasInit	153	2	-	1	+
	DallasAllInitLength	155	0	-	1	+
	DallasWireSearch	156	1	-	1	+
	DallasGet	157	2	-	4	+
	WatchDogInit	158	4	-	0	+
	WatchDogDis	159	0	-	0	+
	WatchDogUpdate	160	0	-	0	+
	WatchDogTrig	161	0	-	0	+
	WatchDogIsOldTrig	162	0	-	1	+

Demo

License

Copyright 2022-2023 #UlinProject Denis Kotlyarov (Денис Котляров)

Licensed under the Apache License, Version 2.0