LuatOS IO multiplexing configuration under firmware#

This document describes the LuatOS and CSDK perspectives

Part of the mapping can be modified by mcu.altfun function.
The external pin layout of different modules is different, but the’ PAD(paddr)’value is the same. to correspond to the “PIN/GPIO correspondence table” document, the document can be found in air780ep.cn
For AT firmware, this document is meaningless, please ignore it.
Cloud compilation and mcu.altfun function can adjust part of the reuse relationship, please refer to the document linked to mcu library
If SIM2 is used, it will take up 4 IO(gpio4/5/6/23)
mcu.iomux The function needs to be used with GPIO multiplexing table. Find the PDF document of GPIO in the table of hardware data and homepage of air780ep.cn

PWM Description#

software channel id	actual hardware channel	corresponding GPIO	corresponding PAD	remarks
0	0	GPIO1	16	AU_OUT,It is recommended to avoid using
1	1	GPIO24	49	MAIN_RI,weak driving ability
2	2	GPIO25	50	AGPIO5,weak driving ability
4	4	GPIO27	52	NetLed,Network Status Light

Description:

The actual available channels are 4 (0/1/2/4), and the 4 channels can be used separately without affecting each other. PWM3/PWM5 has been used by the bottom layer.
However, the same hardware channel, for example, PWM1 and PWM11 both use hardware channel 1, and only one of them can be selected at the same time.**.
Enabling PWM1 will not enable PWM11, enabling PWM1 and enabling PWM22 will not be restricted.
When calling the API of pwm library, fill in’ software channel id’, not GPIO number, not hardware channel number
The current firmware version V1001 does not support the use of other PWM multiplexing channels, and subsequent versions will support

physics uart has 4(0/1/2/3)

uart0 It is a log port (DBG_TX/DBG_RX), which is not recommended. It also has output during startup. LuatOS firmware does not allow users to use it by default uart0
uart1 is the primary serial port (MAIN_TX/MAIN_RX), recommended
uart2 It is a serial port(AUX_TX/AUX_RX)
uart3 Is a standby serial port, no default function
The following mappings are default and supported through ‘mcu.iomux’ configuration
Release is not currently supported uart0

Function	Software Meaning	Corresponding GPIO	Corresponding PAD
DBG_RX	UART0_RX	-	31
DBG_TX	UART0_TX	-	32
MAIN_RX	UART1_RX	GPIO18	33
MAIN_TX	UART1_TX	GPIO19	34
AUX_RX	UART2_RX	GPIO12	27
AUX_TX	UART2_TX	GPIO13	28
UART3_RX	UART3_RX	GPIO34	40
UART3_TX	UART3_TX	GPIO35	41

Function	Software Meaning	Corresponding GPIO	Corresponding PAD	Remarks
I2C0_SCL	I2C0 Clock	GPIO18	13	See later description
I2C0_SDA	I2C0 Data	GPIO19	14	See later description
I2C1_SCL	I2C1 Clock	GPIO29	29
I2C1_SDA	I2C1 Data	GPIO30	30

Attention:

Although the GPIO number of I2C0 is the same as that of UART1/MAIN_UART, the actual GPIO18/19 is multiplexed on UART1/MAIN_UART pin and does not conflict with I2C0
I2C It is a bus structure and can connect multiple devices with different i2c addresses.

There are 3 physical SPIs, of which ‘0/1’ is a general SPI and ‘5’ is a special SPI for LCD screen brushing.
The following mappings are default values and other configuration items are not supported.

Function	Software Meaning	Corresponding GPIO	Corresponding PAD	Remarks
SPI0_CS	SPI0 Chip Select	GPIO8	23	Conflicts with I2C1
SPI0_MOSI	SPI0 Host output	GPIO9	24	conflicts with I2C1
SPI0_MISO	SPI0 Output from machine	GPIO10	25
SPI0_SCL	SPI0 Clock	GPIO11	26
SPI1_CS	SPI1 Select	GPIO12	27	Note conflict with UART2
SPI1_MOSI	SPI1 Host output	GPIO13	28	Note conflict with UART2
SPI1_MISO	SPI1 Output from machine	GPIO14	29
SPI1_SCL	SPI1 Clock	GPIO15	30
SPI5_CLK	LCD Clock	GPIO34	40	LCD _CLK, note conflict with UART3
SPI5_CS	LCD Select	GPIO35	41	LCD _CS, note conflict with UART3
SPI5_RST	LCD Reset	GPIO36	42	LCD_RST
SPI5_SCL	Data Output	GPIO37	43	LCD_DOUT
SPI5_RS	LCD_RS	GPIO38	44	LCD_RS

Attention:

SPI0 It is in conflict with UART2, which is the case.
SPI5 It is a special SPI for LCD screen brushing, and does not support the general SPI function

AONGPIO It is a GPIO that can still maintain a high level during sleep, but the driving ability is very weak.
When ordinary GPIO is configured in input/interrupt mode, the up-down pull cannot be set. If the default up-down pull cannot meet the requirements, it can be set to’0’ to cancel the default up-down pull, and then add the pull-down externally

Air780EP(EC718P/EC718PV The whole system) supports multiple virtual GPIO, and non-GPIO pins are used by software simulation into GPIO.

Number	Name	Function	Remarks
39	wakeup0	Only supports input and interrupt	wakeup0 sleep wake-up pin
40	wakeup1/vbus	Only supports input and interrupt	VBUS of USB, detects whether USB is inserted
41	wakeup2	Only supports input and interrupt	wakeup2 sleep wake-up pin, USIM_DET
46	pwrkey	Only supports input and interrupt	instant power-on key, when normal GPIO is used after power-on

Description:

vbus Decoupled from USB functionality
Different from conventional understanding, USB function is still available without vbus
Before entering sleep, set the above ‘wakeup0/wakeup1/wakeup2’ to interrupt state to realize pin wake-up function
Non-wakeup ordinary GPIO does not support sleep wake-up
wakeup3/wakeup4/wakeup5 Not led out in module

For example, if ‘wakup0’ is set as the wake-up pin, the interrupt callback can be an empty function.

gpio.setup(32, function() end, gpio.PULLUP)

**BOOT Mode requires high USB wiring * *, must do differential line and impedance matching!!!
When there is USB communication, it is impossible to sleep. USB communication can be turned off by pass’ pm.power(pm.USB, false)’
UART1 Can also brush the machine, but need to use the amount of production tool brush, LuaTools temporarily does not support the Air780EP/Air780EPV brush through UART!!!