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WiFi Reset and Power Control From Wiced Host MCU

WiFi Reset and Power Control From Wiced Host MCU

SeyhanA_31
Employee
Employee
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The WiFi module power and reset pins are controlled by the host MCU.

 

BCM943362WCD4:

 

For BCM943362WCD4 evaluation board, the power and reset pins are controlled by the following definitions in .../platforms/BCM943362WCD4/platform.c

 

[WWD_PIN_POWER] = { GPIOB,  2 },

[WWD_PIN_RESET] = { GPIOB,  5 },

 

The "WWD_PIN_POWER" definition in WICED SDK controls the host MCU (STM32F205) PB2 pin. The host MCU PB2 pin controls the VBAT (power) on the WiFi module. Wifi module power completely turned of by the hos MCU to save energy if the WiFi module is not in use at all.

 

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The "WWD_PIN_RESET" definition in Wiced SDK controls the host MCU PB5 pin. The host MCU PB5 pin controls the WLAN_RESET_L (reset) on the WiFi module.
Setting this pin logic level to low causes WiFi module reset.

 

pastedImage_11.png

 

BCM943341WCD1:

 

For BCM943341WCD1 the reset pin is controlled by the following definition in .../platforms/BCM943341WCD1/platform.c

Although it is named as WWD_PIN_POWER but actually controls the reset pin of the BCM943341 SiP module. Reason is being the logic level to reset the BCM943341 SiP module is inverted compared to the other SiP modules.

 

[WWD_PIN_POWER] = { GPIOB,  2 },

 

The "WWD_PIN_POWER" definition in WICED SDK controls the host MCU (STM32F417IGH6) PB2 pin. This pin from the host MCU controls the WL_REG_ON (reset) on the WiFi module.  Setting this pin logic level to high causes WiFi module reset.

 

pastedImage_15.png

 

Unlike on BCM943362WCD4 evaluation board, on BCM943341WCD1 evaluation board the WiFi module power (VBAT) is not controlled by the host MCU. The WiFi module VBAT pin directly connected to the 3.3V via bypass capacitors.

 

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If needed, the similar power switching circuit from BCM943362WCD4 evaluation board could be used on BCM943341 module based designs as well.

 

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