Accessing the nrf52820 pins

RE: Accessing the nrf52820 pins

nRF5xFanboy — Wed, 31 Aug 2022 19:36:19 GMT

Hi MuRa,

sorry to place the reply here, this site sometimes does not show the reply button under recent tickets. ????

F5 => P0.02
F7 => P0.08

Lets say I would like to assign the TWI, namely F5 = SDA and the F7 = SCL ... not really sure how to consider the in/out properties of the TWI.. with regard to the GPIO configuration...

then just change some code in my given example (see earlier posts)

const uint32_t scl_pin = NRF_GPIO_PIN_MAP(0, 2); /*port-0 pin2 (= F5) */
const uint32_t sda_pin = NRF_GPIO_PIN_MAP(0, 8); /*port-0 pin8 (=F7) */

By doing this the nrf52820 will route (internally) the pin F5/F7 not to the GPIO but to the TWImaster.
so no worry about gpio input/output (they do not exist then.

2nd question: about testing.
I think about attaching a oscilloscope (or my favorite Saleae a logic analyzer) to the F5 and F7 and check the signals.

Kind regards,
nRF5xFanBoy

RE: Accessing the nrf52820 pins

MuRa — Tue, 30 Aug 2022 08:55:05 GMT

Hi nRF5xFanBoy and thanks for your reply!

I thought the question is more clear now :)

[quote userid="117866" url="~/f/nordic-q-a/91424/accessing-the-nrf52820-pins/383788"]Do you known which port/pins (based upon your electrical drawing) do you like to assign to the TWI ?[/quote]

Yes, I do! So, if we are looking at the posted el. schematics already here then these are E1, E2, F3, F5, F7 , while on the right hand side are the available nrf52820 pins, see below:

E1 => P0.14

E2 => P0.20

F3 => "not sure what should be used here"

F5 => P0.02

F7 => P0.08

Lets say I would like to assign the TWI, namely F5 = SDA and the F7 = SCL ... not really sure how to consider the in/out properties of the TWI.. with regard to the GPIO configuration...

So, can you quickly shoot an example of how to configure the GPIOs for that? In addition, how would you test, with software, if my GPIOs are healthy either for input or output.

Will have to look at the links provided.

Best.

RE: Accessing the nrf52820 pins

nRF5xFanboy — Tue, 30 Aug 2022 07:06:04 GMT

Hi MuRa,

Great an easy question :) Yes the nordic Micrcontroller is very flexible in routing pins to a specific source (like TWI or SPI or GPIO etc.)

Do you known which port/pins (based upon your electrical drawing) do you like to assign to the TWI ?

more details information on the TWI
https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.0.0%2Fhardware_driver_twi.html

For example :
I will pick the pins 4 & 5 because they are not used and are free (as you can see in you your electrical drawing)
So I in my code below I do assign port/pin P0.04 + P0.05 as scl & sda for the twi - master.

nrf_drv_twi_t twi_drv;

const uint32_t scl_pin = NRF_GPIO_PIN_MAP(0, 4); /*port-0 , pin4* /
const uint32_t sda_pin = NRF_GPIO_PIN_MAP(0, 5); /*port-0 , pin5 */

const nrf_drv_twi_config_t config =
{
.scl = scl_pin,
.sda = sda_pin,
.frequency = (nrf_drv_twi_frequency_t)frequency, // give a value
.interrupt_priority = APP_IRQ_PRIORITY_HIGH,
.clear_bus_init = false,
.hold_bus_uninit = false
};

if ( NRF_SUCCESS != nrf_drv_twi_init( &twi_drv, &config, NULL, NULL ) )
{
  // error
}
else
{
  nrf_drv_twi_enable( &twi_drv_ );
}

Hope my answer does help you, have a nice (coding) day.

Kind regards,
nRF5xFanBoy

RE: Accessing the nrf52820 pins

MuRa — Mon, 29 Aug 2022 19:22:17 GMT

Hello all,

I think I have to change the question here, to aim at what I am looking for :) for example, I am looking at how to configure the GPIOs on the module that is based on the nrf52820 !

For example, on particular GPIOs I want to have the TWI 🙂

On other GPIOs I want to have the interrupt, while on others I would like to blink the led, and so on...

So, how to configure the GPIOs on the nrf52820 with the nrf52sdk is the question , right?

Looking forward to any ideas, suggestions how to tackle this...

Best.

RE: Accessing the nrf52820 pins

MuRa — Mon, 29 Aug 2022 18:55:57 GMT

Hi and thank you for your input!

I will try to answer your questions and elaborate what I had in mind.

[quote userid="117866" url="~/f/nordic-q-a/91424/accessing-the-nrf52820-pins/383744"]

On page 10 you will see the pins identifiers C4 & C5 (not handy labels for software people ;-)

[/quote]

Not sure what are you aiming here? btw SWDCLK, SWDIO , works ok, I can easily program the module.

[quote userid="117866" url="~/f/nordic-q-a/91424/accessing-the-nrf52820-pins/383744"]I only do not see any official TWI (i2c) pins coming out of the microcontroller / PAN1781 module.
[/quote]

I do not see it either, this is why I am looking at how to use the available GPIOs ... I think the GPIOs can be used for TWI...

[quote userid="117866" url="~/f/nordic-q-a/91424/accessing-the-nrf52820-pins/383744"]It tells you that it is impossble to use theese pins as a normal TWI pins?
[/quote]

I am not trying to use the SWD..pins for the TWI...

[quote userid="117866" url="~/f/nordic-q-a/91424/accessing-the-nrf52820-pins/383744"]unclear what you want with the TWI on the pan1781 route to the swd pins?[/quote]

See above...

[quote userid="117866" url="~/f/nordic-q-a/91424/accessing-the-nrf52820-pins/383744"]2nd question "I have tried to toggle the P0.14 .... now I would like to do the same with the P0.20?"
The the answer is simple
nrf_gpio_pin_write(12, 1); // to make the gpio level high (assume positive signal level.)
nrf_gpio_pin_write(12, 0); // to make the gpio level low [/quote]

Thank you for that, it makes sense! 🙂

[quote userid="117866" url="~/f/nordic-q-a/91424/accessing-the-nrf52820-pins/383744"]The names are copied from the FT232R chip datasheet [/quote]

Thanks for that , will have a look...

Thanks and the same!

Best.

RE: Accessing the nrf52820 pins

nRF5xFanboy — Mon, 29 Aug 2022 18:13:28 GMT

Hi MuRa,

Sorry for the late feedback (i had a long ad hoc meeting ;-)

mmh this electronic drawing is not very clear in the pin naming (it's a good puzzle)
You just need to hunt all the chip's proper datahseets and collect all the information.

1st question about the twi_config / pins

Looking at the PAN1781 product datahseet
nl.mouser.com/.../IntegrationGuideRFModulePAN1781Series052421.pdf
On page 10 you will see the pins identifiers C4 & C5 (not handy labels for software people ;-)

if you search the labels in the WM PAN1781 Product Specification.pdf
https://mediap.industry.panasonic.eu/assets/custom-upload/Devices/Wireless%20Connectivity/Bluetooth%20Low%20Energy%20Modules/PAN1781/WM%20PAN1781%20Product%20Specification.pdf

On page 11 you will find:
C4 = SWDIO , Digital BI, Serial Wire Data I/O
C5 = SWDCLK, Digital IN, Serial Wire Data Clock

I only do not see any official TWI (i2c) pins coming out of the microcontroller / PAN1781 module.
I only see the SWDCLK & SWDIO.
As you can see in the datasheet of the Nordic nrf52820 https://infocenter.nordicsemi.com/pdf/nRF52820_OPS_v0.7.pdf.
It tells you that it is impossble to use theese pins as a normal TWI pins?
More information on the control access port (for the debug access port) is on page 43

unclear what you want with the TWI on the pan1781 route to the swd pins?

2nd question "I have tried to toggle the P0.14 .... now I would like to do the same with the P0.20?"
The the answer is simple
nrf_gpio_pin_write(12, 1); // to make the gpio level high (assume positive signal level.)
nrf_gpio_pin_write(12, 0); // to make the gpio level low

3rd question: "reach the pin F3"
The names are copied from the FT232R chip datasheet (https://nl.mouser.com/datasheet/2/163/DS_FT232R-11534.pdf see page 7)
The USB D- wire is called at the FT232RQ -> pin no. 15 USB Data Signal Plus
The USB D+ wire is called at the FT232RQ -> pin no. 16 USB Data Signal Minus

The 'M' perhaps indicate the PAN1781 is a bus-Master (or MCU) on this interface?
I am not sure, my advise, just try to follow the interfacing as is described in the FT232R chip datasheet.

Thanks for the nice puzzle

Hope my answers do help you, have a nice day.

Kind regards,
nRF5xFanBoy

RE: Accessing the nrf52820 pins

MuRa — Mon, 29 Aug 2022 12:57:35 GMT

The el schematics is here: New Output (panasonic.de) !

Best.

RE: Accessing the nrf52820 pins

MuRa — Mon, 29 Aug 2022 12:55:43 GMT

There is no rest of the hardware, this is a prototype :)

RE: Accessing the nrf52820 pins

MuRa — Mon, 29 Aug 2022 12:54:32 GMT

True that, I am looking at the el. schematics, ok, for example, how can someone enable or use the pin P0.20?

for example, I have tried to toggle the P0.14 with the nrf_gpio_pin_write(14, 1); //P(0.14) / nrf_gpio_pin_clear(14); the led, so, now I would like to do the same with the P0.20?

Further more, I am trying to reach the pin F3, have a look at the attached pic, but not sure what M P stands for?

Was hopping that the GPIO could be assigned via software ...

BEST.

RE: Accessing the nrf52820 pins

nRF5xFanboy — Mon, 29 Aug 2022 12:48:14 GMT

Hi Mura,

Do you have an electrical drawing of your board because it
holds the answer to you question of the TWI port/pins.

Kind regards,
nRF5xFanBoy

RE: Accessing the nrf52820 pins

nRF5xFanboy — Mon, 29 Aug 2022 12:45:38 GMT

Hi Mura,

Panasonic PAN1781 is just a module.
What is vendor of the rest of the hardware?

One of advantage of the Noridc micrcontroller nrf52 is you can configure the routing of IO pins.
So they are not fixed, yet.
The TWI port/pins of the nrf52820 inside the pan1781 module are becoming fixed by solder the pan1781 and external parts onto the PCB.

Thus a electrical drawing of your board is mandatory to find out the TWI port/pins.

Kind regards,
nRF5xFanBoy

RE: Accessing the nrf52820 pins

MuRa — Mon, 29 Aug 2022 12:30:20 GMT

PAN1781

RE: Accessing the nrf52820 pins

nRF5xFanboy — Mon, 29 Aug 2022 12:30:00 GMT

What vendor/brand is the board with your nrf52820

RE: Accessing the nrf52820 pins

nRF5xFanboy — Mon, 29 Aug 2022 12:29:01 GMT

Hi MuRa,

The correct way to be sure what pin/port is used is to look & check with the electrical drawing of your board.
Sometimes it is easy because the make has written the silkscreen text on the PCB (like with the nRF52DK)

Kind regards,
nRF5xFanBoy

RE: Accessing the nrf52820 pins

MuRa — Mon, 29 Aug 2022 12:20:59 GMT

Hey and cheers,

so the number 8 and 2 could be easily used? 🙂

Best.

RE: Accessing the nrf52820 pins

nRF5xFanboy — Mon, 29 Aug 2022 12:18:50 GMT

Hi MuRa,

nrf gpio are always made up of a combination of port & pin number.
thus ..
"the numbers 26 and 27 are simply used, as 26 and 27"
simply implies the port value is zero (0)

Kind regards,
nRF5xFanBoy

RE: Accessing the nrf52820 pins

MuRa — Mon, 29 Aug 2022 12:16:43 GMT

For example, if I want to use certain ports, for the LED, as gpio they need to be initialized, like that bsp_board_init(BSP_INIT_LEDS); otherwise it does not work ...

Just a hint ...

Best.