Diolan

9.4. GPIO_SET_PWM_CFG (0x07)

The GPIO_SET_PWM_CFG command configures pulse width modulation (PWM) settings for specified I/O pins. For more detailed information see Section 9.1, “Pulse Width Modulation (PWM) ”.

GPIO_SET_PWM_CFG Command

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Byte 0		GPIO_SET_PWM_CFG	Command ID (0x07).
Byte 1		ECHO	Echo to associate a command with the response.
Byte 2	Bit 7..4	PORT	GPIO port.
Byte 2	Bit 3..0	ON	PWM state: on/off.
Byte 3		MASK	Data mask.
Byte 4		T0L	Low time of the pulse (least significant byte).
Byte 5		T0H	Low time of the pulse (most significant byte).
Byte 6		T1L	High time of the pulse (least significant byte).
Byte 7		T1H	High time of the pulse (most significant byte).

Command is an 8-byte array of the following format:

Byte 0: GPIO_SET_PWM_CFG (0x07)

This byte contains command ID (command type). It should be set to 0x07.

Byte 1: ECHO

This byte is used to associate a response received from GPIO-24 adapter with a specific command. Response will contain exactly the same value in its echo byte.

Byte 2:

Bits 7..4	Bits 3..0
PORT	ON

Bits 7..4: PORT

0 – GPIO PORT A;
1 – GPIO PORT B;
2 – GPIO PORT C.

Bits 3..0: ON

The PWM state (on/off):

1 – the pins will be switched to PWM mode. GPIO_GET_CFG and GPIO_GET_PIN_CFG commands will return GPIO_CFG_PWM (0x2) value for the pins. The pins can be used only by the PWM module;
0 – the PWM mode will be switched off on the pins. GPIO_GET_CFG and GPIO_GET_PIN_CFG commands will return GPIO_CFG_NOT_CONFIGURED (0xf) value for the pins. The pins can be used by any module.

Byte 3: MASK

Data mask to use when modifying PWM settings for I/O pins. It is well known that a byte consists of 8 bits (which can be 0 or 1). This characteristic is used to create a mask. The mask value allows to modify certain pins, leaving rest of the pins unchanged. Note, that only the pins with mask bit set to 1 will be affected.

Bytes 4, 5: T0L/T0H

Byte 4: T0L – least significant byte (low byte) of low time of the pulse.

Byte 5: T0H – most significant byte (high byte) of low time of the pulse.

Low time is a time period when the output equals to 0. It is specified in ms in the range from 1 to 65535 ms (65.535 seconds).

Bytes 6, 7: T1L/T1H

Byte 6: T1L – least significant byte (low byte) of high time of the pulse.

Byte 7: T1H – most significant byte (high byte) of high time of the pulse.

High time is a time period when the output equals to 1. It is specified in ms in the range from 1 to 65535 ms (65.535 seconds).

For convenience GPIO_SET_PWM_CFG_CMD structure is declared in reports.h file.

GPIO-24 adapter sends GPIO_SET_PWM_CFG response after command execution.

GPIO_SET_PWM_CFG Response

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Byte 0	GPIO_SET_PWM_CFG	Response ID (0x07).
Byte 1	ECHO	Echo to associate a command with the response.
Byte 2	ST	Status of the command execution.
Byte 3..7	Reserved	Reserved