nRF52832 SPI

RE: nRF52832 SPI

jbeh444 — Thu, 14 Dec 2023 23:38:45 GMT

It looks like my problem was I needed to create a binding file instead of using compatible = "spi-device".

Devicetree: SPI device - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

RE: nRF52832 SPI

jbeh444 — Wed, 13 Dec 2023 19:59:14 GMT

Hello,

I hope your day is going well!

#1. Is this the right way to create a SPI node? I have scoured the examples you gave me and am still not getting the SPI working.

&spi0 {
    //compatible = "nordic,nrf-spi";
	status = "okay";
    cs-gpios = <&gpio0 28 GPIO_ACTIVE_LOW>; 
    a: spi-dev-a@0 {
        compatible = "spi-device";
        reg = <0>;
        spi-max-frequency = <10000000>;                      
        //status = "okay";
    };
};

#2. I need to change the default pins as well. Sck = P0.27, mosi/miso P0.25.

#3. Can miso/mosi be on the same pin? The sensor I am using uses mosi/miso on the same pin.

#4. Is this the right way to define the device in my files?

#define SPI0_NODE DT_NODELABEL(a)
static const struct spi_dt_spec dev_spi = SPI_DT_SPEC_GET(SPI0_NODE, SPI_OP_MODE_MASTER, 0);

I am sorry I have read the documentation and must be missing some understanding.

Thank you in advance for all of your help.

RE: nRF52832 SPI

Amanda Hsieh — Mon, 13 Nov 2023 22:19:57 GMT

Hi,

The GPIO pins passed to 'nrfx_twim_init' will be configured internally in the driver to match the pin configurations recommended in the product specification here: Master mode pin configuration. This means you don't have to initialize the pins yourself.

https://github.com/NordicSemiconductor/nrfx/blob/1aa7824f45d46b5f81250801868bef050ba72440/drivers/src/nrfx_twim.c#L274

-Amanda H.

RE: nRF52832 SPI

jbeh444 — Sat, 11 Nov 2023 20:41:24 GMT

[quote userid="77782" url="~/f/nordic-q-a/105333/nrf52832-spi/454761"]You could set the pin GPIO_OPEN_DRAIN connected to ground / GPIO_ACTIVE_LOW for active low. See this General-Purpose Input/Output (GPIO) doc. [/quote]

The examples are just fragments, and I don't fully understand how to use them.

I was attempting to make a node for the gpios but it doesn't seem to work. Is there a working device tree example I could reference. I just want to set pin P0.26 to open drain with minimal steps.

Here is my current overlay file:

/*The i2c0 controller and set the address to 0x19 (SDO to VDDIO)(Seeed address) 
                                          or 0x18 (SDO to GND)*/
&i2c0 {   
    mysensor: mysensor@19{ 
        /*changed default sda to 25 by editing nrf52dk_nrf52832-pinctrl.dtsi
        this is located in c:\ncs\v2.4.0\zephyr\boards\arm\nrf52dk_nrf52832 */
        compatible = "i2c-device";
        status = "okay";
        reg = < 0x19 >; //
        label = "mysensor";
        //twim_sda-gpios = <&gpio0 25 0>; 
        /*Turn off when not in use */
        i2c-gpio,disable-on-idle; /*not sure if this works */       
    };
};
// Changed to active high and pull up and worked!!!
&button0{
    gpios = <&gpio0 24 (GPIO_PULL_DOWN | GPIO_ACTIVE_HIGH)>;
};
//set sdo to ground

//uses less power? (seems like 200uA less power on average)
// &uart0 {
//     status = "disabled";
// };
/*This will setup the voltage divider to measure through voltage divider */
 / {
    vbatt {
       compatible = "voltage-divider";
       io-channels = <&adc 0>; // battery measure
       output-ohms = <220000>;
       full-ohms = <(1500000 + 220000)>;
       power-gpios = <&gpio0 3 0>; //Battery enable
    };
 };

I just want to make a gpio or reference a node and change 26 to an open drain.

// #define SDO_NODE DT_NODELABEL(sdo)

//static const struct gpio_dt_spec spec = GPIO_DT_SPEC_GET(SDO_NODE, gpios);

if (!device_is_ready(SDO.port)) {
    return 0;
}

RE: nRF52832 SPI

jbeh444 — Sat, 11 Nov 2023 19:42:59 GMT

I went into here and was able to change the default pins to what I needed.

C:\ncs\v2.4.0\zephyr\boards\arm\nrf52dk_nrf52832\nrf52dk_nrf52832-pinctrl.dtsi

please let me know if this is a good solution. Thank you.

RE: nRF52832 SPI

jbeh444 — Sat, 11 Nov 2023 19:28:30 GMT

[quote userid="77782" url="~/f/nordic-q-a/105333/nrf52832-spi/454761"]See the example https://github.com/nrfconnect/sdk-zephyr/blob/ff85910bf8ed1aac0571bca0e7f206782234efbb/samples/sensor/adt7420/boards/nrf52dk_nrf52832.overlay [/quote]

I didn't see an example of how to change the pins at this link. Would you happen to know another example? thank you very much.

RE: nRF52832 SPI

Amanda Hsieh — Wed, 08 Nov 2023 17:34:29 GMT

Hi,

[quote user="jbeh444"]Is there a way to set pin P0.26 to ground or active low or a voltage. How would I go about setting that pin? [/quote]

You could set the pin GPIO_OPEN_DRAIN connected to ground / GPIO_ACTIVE_LOW for active low. See this General-Purpose Input/Output (GPIO) doc.

[quote user="jbeh444"]also how do I change the default pins on I2c? [/quote]

See the example https://github.com/nrfconnect/sdk-zephyr/blob/ff85910bf8ed1aac0571bca0e7f206782234efbb/samples/sensor/adt7420/boards/nrf52dk_nrf52832.overlay

-Amanda H.

RE: nRF52832 SPI

jbeh444 — Wed, 08 Nov 2023 00:16:03 GMT

Is there a way to set pin P0.26 to ground or active low or a voltage. How would I go about setting that pin? This would enable my I2c to work (hopefully).

also how do I change the default pins on I2c?

thank you so very much for all of your help!!!

RE: nRF52832 SPI

Amanda Hsieh — Fri, 03 Nov 2023 20:08:01 GMT

Hi,

Seems your overlay doesn't set the device correctly.

Here is an example showing how to set the devices tree for connecting SPI sensor on nRF52DK: https://github.com/nrfconnect/sdk-zephyr/blob/ff85910bf8ed1aac0571bca0e7f206782234efbb/samples/sensor/icm42605/boards/nrf52dk_nrf52832.overlay

If you want to use the nrfx_spim driver, since the Zephyr driver doesn't support all the Nordic specific functionality (such as triggering SPI transcations via DPPI), and there are some good nrfx examples available here.

I would recommend taking a look at one of the nrfx_spim examples and try to setup the SPI in a similar way.

Regards,
Amanda H.