RAK811 breakout board GPIO questions

#1

Hi,
I’m trying to use the at+get_config=device:gpio:X to read a GPIO pin.
I’m assuming that the command will initialize the GPIO as input by default. Cold you please confirm ?
What’s the default for the GPIO pins ? Open-drain/pull-up/pull-down ? I’d think open-drain as multiple readings on the same pin give random 0/1 results.
Another issue is that I can’t find a mapping between the parameter of the AT command and the GPIO pin number as described on the breakout board.
The only one that seemed to work was at+get_config=device:gpio:23 that was reading PB14, PIN 11 on the diagram.

Thanks

#2

The default GPIO pins is pull-down. gpio:2—>PB12,gpio:3—>PB14,gpio:4—>PB15. it is related to the rak811 module.

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#3

Thanks,
I’m assuming that when you say GPIO3 you refer to the value I’d use in the AT command, right ?
As you can see, multiple reads give different values, if the pin was configured with pull-down, I’d expect to be always 0

at+get_config=device:gpio:3
Pin level is:1
OK
at+get_config=device:gpio:3
Pin level is:0
OK
at+get_config=device:gpio:3
Pin level is:1
OK
at+get_config=device:gpio:3
Pin level is:1
OK
at+get_config=device:gpio:3
Pin level is:1
OK
at+get_config=device:gpio:3
Pin level is:1
OK
at+get_config=device:gpio:3
Pin level is:1
OK
at+get_config=device:gpio:3
Pin level is:0
OK
at+get_config=device:gpio:3
Pin level is:1
OK

Also, PB14, on the breakout board positioned in the lower right corner, for me works when using the following: at+set_config=device:gpio:23:0

#4

[email protected]
GPIO read default set PIN_OPEN_DRAIN.
Please check the external circuit of the lower pin 3.

#5

Thanks Leopold, that matches what I’ve tested.
What about the pin mapping ? I’m still confused.

Sal

#6

at+get_config=device:gpio:X X means pin number of the RAK811 module.
the pin mapping checkout this link :https://doc.rakwireless.com/datasheet/rakproducts/pin-definition—rak811-lora-module

#7

Thanks Leopold,
I did verify one more time, and the issue is with the pinout description on the breakout board.

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image6001×6000 1.28 MB

This is what I could verify on the board and validated all pins

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image747×719 44.3 KB

In green, the rak811 module pinout. The ones with red border are not accepted by the RUI at commands (RUI_AT_PARAMETER_INVALID_2)

#8

How did you get the following picture, and can you take a screenshot to explain the problem when the pin in the red box cannot receive AT command?

#9

Nicholas,
the first picture is from your documentation: https://doc.rakwireless.com/rak811-lora---breakout-module/burning-bootloader-into-the-device
The second one, I did draw myself.

As for the errors, that’s what I get
at+set_config=device:gpio:13:0
ERROR: RUI_AT_PARAMETER_INVALID 2
at+set_config=device:gpio:10:0
ERROR: RUI_AT_PARAMETER_INVALID 2

while it works fine for the others

at+set_config=device:gpio:9:0
OK
at+set_config=device:gpio:4:0
OK
at+set_config=device:gpio:20:0
OK
at+set_config=device:gpio:5:0
OK
at+set_config=device:gpio:8:0
OK
at+set_config=device:gpio:3:0
OK
at+set_config=device:gpio:2:0
OK
at+set_config=device:gpio:15:0
OK
at+set_config=device:gpio:16:0
OK
at+set_config=device:gpio:14:0
OK

#10

Hi @saltar
Pin number 10 an 13 are used to SWD interface,so they can’t be used to GPIO.

#11

Thanks Leopold.
I’d suggest you guys update the documentation on the breakout board and the default GPIO status of PIN_OPEN_DRAIN.
I’d also suggest to add the capability of configuring the GPIO inputs with an internal pull-up.