CYW20706的GPIO上拉电阻影响输入

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niwa_1296046
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HI,

CYW20706的GPIO默认配置为输入上拉时,电平都只能到2V多,而不能到正常的3.3V左右(同理,在做ADC检测的时候,内部电阻严重影响ADC的电压检测).

用wiced_hal_gpio_configure_pin去设置,没有效果,请问有什么办法可以设置不用上拉,谢谢?

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Owen_Zhang123
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请问你是准备用这个GPIO做ADC采样吗?如果外部有分压电阻的话,阻值要小于10K才可以。

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BoonT_56
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I added the following line into the hello_sensor app and I was able to get 3.3V on pin5 of J19 of the CYW920706WCDEVAL board. Can you verify?

wiced_hal_gpio_configure_pin( WICED_P27, GPIO_INPUT_ENABLE, WICED_GPIO_BUTTON_DEFAULT_STATE )

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niwa_1296046
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hi boont,

请帮忙试试P15或者P4, 我客户说他试了没有作用,谢谢

wiced_hal_gpio_configure_pin( WICED_P15, GPIO_INPUT_ENABLE, WICED_GPIO_BUTTON_DEFAULT_STATE )

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BoonT_56
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On the CYW920706WCDEVAL board, I download the hello_sensor app (in default) and I was able to measure 3.3V on Pin2 of J30.

Then I add the following line explicitly to test again:

wiced_hal_gpio_configure_pin( WICED_P15, GPIO_INPUT_ENABLE | GPIO_PULL_DOWN | GPIO_EN_INT_BOTH_EDGE, WICED_GPIO_BUTTON_DEFAULT_STATE );*/

I got 1.6V which is the tri-stated state. I did not get a 2V measurement reported by you. Are you using our eval board for development?

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niwa_1296046
Level 2
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hi boont,

是1.7v,你这是配置成上下拉了吧。

但是有没有办法可以断开内部的上拉电阻。我们试了各种配置都不行。

wiced_hal_gpio_configure_pin( WICED_P15, GPIO_INPUT_ENABLE | GPIO_PULL_UP_DOWN_NONE , GPIO_PIN_OUTPUT_LOW);

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BoonT_56
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Even without explicitly specifying the gpio, I was able to measure 3.3V on P15 and P4 by default. Are you using our EVK board? Can you check out your HW board with our default apps? If this continues, please create a tech support case and we will need those details.

In any case, GPIO_PULL_UP_DOWN_NONE would have meant no pull resistor at all.

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