Hello,
I am trying to understand if I am able to use the SPI pins as GPIO when SPI is not being used. This post says that we could be able to use I2C and SPI pins besides normal GPIO pins, but if there is a way, I can't seem to find it.
Thank you,
Aleix.
Hi Karl,
Yes, this part is a bit trickier - sorry for not mentioning it in my last comment.
To use these pins, it will require that you cut the Solderbridges 10 and 11 ( please see the Hardware schematics ) and solder a connection to only 1 end of the now-cut solder bridge.
This will require some steady hands to do the soldering, since the SB pads are quite small, but its absolutely doable.
This information is very useful, but we can't consider this approach at the moment, because a cable to P0.10 would be easier to solder. Also, the advantage of having a test point at the top is that we can use pins with springs to connect to them, but that wouldn't be possible with half of a solder bridge, unfortunately.
Hm.. Could you share what you have ( had ) previously done to disable the SPI? You mentioned earlier that you had disabled it, but not how you had done it - I just wanted to verify what you had done to achieve this, since you were not able to control the pin using the code snippet you posted. Could you perhaps also share the relevant parts of your .overlay file?
We would much rather achieve this solution. Prior to creating this thread, all I did was try to "disabling" it just like you proposed me before, but got the same error. Then I only tried to redirect the SCK-SPI pin (originally on pin 3) to another pin.
I also tried to understand why writing "disabled" on the .overlay file would give an error. Tried to confirm if the SPI was disabled or not by having a look on the builded .dts file. I assumed it was already disabled because I think everything is unless you activate it by adding the corresponding CONFIG inside prj.conf.
All I have in my .overlay file is a change in the speed of the I2C bus, so I don't think its anything related with it. However, above you have my prj.conf file and also here I add the .dts file of my build.
/dts-v1/;
/ {
#address-cells = < 0x1 >;
#size-cells = < 0x1 >;
model = "Nordic Thingy91 nRF9160";
compatible = "nordic,thingy91-nrf9160";
chosen {
zephyr,flash-controller = &flash_controller;
zephyr,entropy = &cryptocell_sw;
zephyr,console = &uart0;
zephyr,shell-uart = &uart0;
zephyr,uart-mcumgr = &uart0;
zephyr,flash = &flash0;
zephyr,sram = &sram0_ns;
zephyr,code-partition = &slot0_ns_partition;
};
aliases {
flash-controller = &flash_controller;
rtc-0 = &rtc0;
rtc-1 = &rtc1;
uart-0 = &uart0;
uart-1 = &uart1;
uart-2 = &uart2;
uart-3 = &uart3;
adc-0 = &adc;
egu-0 = &egu0;
egu-1 = &egu1;
egu-2 = &egu2;
egu-3 = &egu3;
egu-4 = &egu4;
egu-5 = &egu5;
gpio-0 = &gpio0;
gpiote-0 = &gpiote;
i2c-0 = &i2c0;
i2c-1 = &i2c1;
i2c-2 = &i2c2;
i2c-3 = &i2c3;
i2s-0 = &i2s0;
pdm-0 = &pdm0;
spi-0 = &spi0;
spi-1 = &spi1;
spi-2 = &spi2;
spi-3 = &spi3;
pwm-0 = &pwm0;
pwm-1 = &pwm1;
pwm-2 = &pwm2;
pwm-3 = &pwm3;
wdt-0 = &wdt;
timer-0 = &timer0;
timer-1 = &timer1;
timer-2 = &timer2;
sw0 = &button0;
led0 = &red_led;
led1 = &green_led;
led2 = &blue_led;
sense-led0 = &sense_red_led;
sense-led1 = &sense_green_led;
sense-led2 = &sense_blue_led;
rgb-pwm = &pwm0;
buzzer-pwm = &pwm1;
nmos-pwm = &pwm2;
};
soc {
#address-cells = < 0x1 >;
#size-cells = < 0x1 >;
compatible = "nordic,nRF9160-SICA", "nordic,nRF9160", "nordic,nRF91", "simple-bus";
interrupt-parent = < &nvic >;
ranges;
nvic: interrupt-controller@e000e100 {
compatible = "arm,v8m-nvic";
reg = < 0xe000e100 0xc00 >;
interrupt-controller;
#interrupt-cells = < 0x2 >;
arm,num-irq-priority-bits = < 0x3 >;
phandle = < 0x1 >;
};
systick: timer@e000e010 {
compatible = "arm,armv8m-systick";
reg = < 0xe000e010 0x10 >;
status = "disabled";
};
sram0: memory@20000000 {
compatible = "mmio-sram";
reg = < 0x20000000 0x10000 >;
};
peripheral@40000000 {
#address-cells = < 0x1 >;
#size-cells = < 0x1 >;
ranges = < 0x0 0x40000000 0x10000000 >;
flash_controller: flash-controller@39000 {
compatible = "nordic,nrf91-flash-controller";
reg = < 0x39000 0x1000 >;
#address-cells = < 0x1 >;
#size-cells = < 0x1 >;
label = "NRF_FLASH_DRV_NAME";
flash0: flash@0 {
compatible = "soc-nv-flash";
label = "NRF_FLASH";
erase-block-size = < 0x1000 >;
write-block-size = < 0x4 >;
reg = < 0x0 0x100000 >;
partitions {
compatible = "fixed-partitions";
#address-cells = < 0x1 >;
#size-cells = < 0x1 >;
boot_partition: partition@0 {
label = "mcuboot";
reg = < 0x0 0x10000 >;
};
slot0_partition: partition@10000 {
label = "image-0";
reg = < 0x10000 0x30000 >;
};
slot0_ns_partition: partition@40000 {
label = "image-0-nonsecure";
reg = < 0x40000 0x40000 >;
};
slot1_partition: partition@80000 {
label = "image-1";
reg = < 0x80000 0x30000 >;
};
slot1_ns_partition: partition@b0000 {
label = "image-1-nonsecure";
reg = < 0xb0000 0x40000 >;
};
scratch_partition: partition@f0000 {
label = "image-scratch";
reg = < 0xf0000 0xa000 >;
};
storage_partition: partition@fa000 {
label = "storage";
reg = < 0xfa000 0x6000 >;
};
};
};
};
adc: adc@e000 {
compatible = "nordic,nrf-saadc";
reg = < 0xe000 0x1000 >;
interrupts = < 0xe 0x1 >;
status = "okay";
label = "ADC_0";
#io-channel-cells = < 0x1 >;
};
dppic: dppic@17000 {
compatible = "nordic,nrf-dppic";
reg = < 0x17000 0x1000 >;
status = "okay";
label = "DPPIC";
};
egu0: egu@1b000 {
compatible = "nordic,nrf-egu";
reg = < 0x1b000 0x1000 >;
interrupts = < 0x1b 0x1 >;
status = "okay";
};
egu1: egu@1c000 {
compatible = "nordic,nrf-egu";
reg = < 0x1c000 0x1000 >;
interrupts = < 0x1c 0x1 >;
status = "okay";
};
egu2: egu@1d000 {
compatible = "nordic,nrf-egu";
reg = < 0x1d000 0x1000 >;
interrupts = < 0x1d 0x1 >;
status = "okay";
};
egu3: egu@1e000 {
compatible = "nordic,nrf-egu";
reg = < 0x1e000 0x1000 >;
interrupts = < 0x1e 0x1 >;
status = "okay";
};
egu4: egu@1f000 {
compatible = "nordic,nrf-egu";
reg = < 0x1f000 0x1000 >;
interrupts = < 0x1f 0x1 >;
status = "okay";
};
egu5: egu@20000 {
compatible = "nordic,nrf-egu";
reg = < 0x20000 0x1000 >;
interrupts = < 0x20 0x1 >;
status = "okay";
};
i2s0: i2s@28000 {
compatible = "nordic,nrf-i2s";
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0x28000 0x1000 >;
interrupts = < 0x28 0x1 >;
status = "disabled";
label = "I2S_0";
};
kmu: kmu@39000 {
compatible = "nordic,nrf-kmu";
reg = < 0x39000 0x1000 >;
interrupts = < 0x39 0x1 >;
status = "okay";
};
pdm0: pdm@26000 {
compatible = "nordic,nrf-pdm";
reg = < 0x26000 0x1000 >;
interrupts = < 0x26 0x1 >;
status = "disabled";
label = "PDM_0";
};
regulators: regulator@4000 {
compatible = "nordic,nrf-regulators";
reg = < 0x4000 0x1000 >;
status = "okay";
};
vmc: vmc@3a000 {
compatible = "nordic,nrf-vmc";
reg = < 0x3a000 0x1000 >;
status = "okay";
};
uart0: uart@8000 {
compatible = "nordic,nrf-uarte";
reg = < 0x8000 0x1000 >;
interrupts = < 0x8 0x1 >;
status = "okay";
label = "UART_0";
current-speed = < 0x1c200 >;
tx-pin = < 0x12 >;
rx-pin = < 0x13 >;
rts-pin = < 0x14 >;
cts-pin = < 0x15 >;
};
uart1: uart@9000 {
compatible = "nordic,nrf-uarte";
reg = < 0x9000 0x1000 >;
interrupts = < 0x9 0x1 >;
status = "okay";
label = "UART_1";
current-speed = < 0xf4240 >;
tx-pin = < 0x16 >;
rx-pin = < 0x17 >;
rts-pin = < 0x18 >;
cts-pin = < 0x19 >;
};
uart2: uart@a000 {
compatible = "nordic,nrf-uarte";
reg = < 0xa000 0x1000 >;
interrupts = < 0xa 0x1 >;
status = "disabled";
label = "UART_2";
};
uart3: uart@b000 {
compatible = "nordic,nrf-uarte";
reg = < 0xb000 0x1000 >;
interrupts = < 0xb 0x1 >;
status = "disabled";
label = "UART_3";
};
i2c0: i2c@8000 {
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0x8000 0x1000 >;
clock-frequency = < 0x186a0 >;
interrupts = < 0x8 0x1 >;
status = "disabled";
label = "I2C_0";
};
i2c1: i2c@9000 {
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0x9000 0x1000 >;
clock-frequency = < 0x186a0 >;
interrupts = < 0x9 0x1 >;
status = "disabled";
label = "I2C_1";
};
i2c2: i2c@a000 {
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0xa000 0x1000 >;
clock-frequency = < 0x186a0 >;
interrupts = < 0xa 0x1 >;
status = "okay";
label = "I2C_2";
compatible = "nordic,nrf-twim";
sda-pin = < 0xb >;
scl-pin = < 0xc >;
bme680@76 {
compatible = "bosch,bme680";
label = "BME680";
reg = < 0x76 >;
};
bh1749@38 {
compatible = "rohm,bh1749";
label = "BH1749";
reg = < 0x38 >;
int-gpios = < &gpio0 0x1b 0x0 >;
};
};
i2c3: i2c@b000 {
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0xb000 0x1000 >;
clock-frequency = < 0x186a0 >;
interrupts = < 0xb 0x1 >;
status = "disabled";
label = "I2C_3";
};
spi0: spi@8000 {
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0x8000 0x1000 >;
interrupts = < 0x8 0x1 >;
status = "disabled";
label = "SPI_0";
};
spi1: spi@9000 {
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0x9000 0x1000 >;
interrupts = < 0x9 0x1 >;
status = "disabled";
label = "SPI_1";
};
spi2: spi@a000 {
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0xa000 0x1000 >;
interrupts = < 0xa 0x1 >;
status = "disabled";
label = "SPI_2";
};
spi3: spi@b000 {
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0xb000 0x1000 >;
interrupts = < 0xb 0x1 >;
status = "okay";
label = "SPI_3";
compatible = "nordic,nrf-spim";
sck-pin = < 0x3 >;
mosi-pin = < 0x4 >;
miso-pin = < 0x5 >;
cs-gpios = < &gpio0 0x8 0x0 >, < &gpio0 0x7 0x0 >;
adxl362@0 {
compatible = "adi,adxl362";
label = "ADXL362";
spi-max-frequency = < 0x7a1200 >;
reg = < 0x0 >;
int1-gpios = < &gpio0 0x9 0x0 >;
};
adxl372@1 {
compatible = "adi,adxl372";
label = "ADXL372";
spi-max-frequency = < 0x7a1200 >;
reg = < 0x1 >;
int1-gpios = < &gpio0 0x6 0x0 >;
};
};
pwm0: pwm@21000 {
compatible = "nordic,nrf-pwm";
reg = < 0x21000 0x1000 >;
interrupts = < 0x21 0x1 >;
status = "okay";
label = "PWM_0";
#pwm-cells = < 0x1 >;
ch0-pin = < 0x1d >;
ch1-pin = < 0x1e >;
ch2-pin = < 0x1f >;
};
pwm1: pwm@22000 {
compatible = "nordic,nrf-pwm";
reg = < 0x22000 0x1000 >;
interrupts = < 0x22 0x1 >;
status = "okay";
label = "PWM_1";
#pwm-cells = < 0x1 >;
ch0-pin = < 0x1c >;
};
pwm2: pwm@23000 {
compatible = "nordic,nrf-pwm";
reg = < 0x23000 0x1000 >;
interrupts = < 0x23 0x1 >;
status = "okay";
label = "PWM_2";
#pwm-cells = < 0x1 >;
ch0-pin = < 0xd >;
ch1-pin = < 0xe >;
ch2-pin = < 0xf >;
ch3-pin = < 0x10 >;
};
pwm3: pwm@24000 {
compatible = "nordic,nrf-pwm";
reg = < 0x24000 0x1000 >;
interrupts = < 0x24 0x1 >;
status = "okay";
label = "PWM_3";
#pwm-cells = < 0x1 >;
};
gpio0: gpio@842500 {
compatible = "nordic,nrf-gpio";
gpio-controller;
reg = < 0x842500 0x300 >;
#gpio-cells = < 0x2 >;
label = "GPIO_0";
status = "okay";
phandle = < 0x2 >;
};
rtc0: rtc@14000 {
compatible = "nordic,nrf-rtc";
reg = < 0x14000 0x1000 >;
interrupts = < 0x14 0x1 >;
status = "okay";
clock-frequency = < 0x8000 >;
prescaler = < 0x1 >;
label = "RTC_0";
};
rtc1: rtc@15000 {
compatible = "nordic,nrf-rtc";
reg = < 0x15000 0x1000 >;
interrupts = < 0x15 0x1 >;
status = "okay";
clock-frequency = < 0x8000 >;
prescaler = < 0x1 >;
label = "RTC_1";
};
clock: clock@5000 {
compatible = "nordic,nrf-clock";
reg = < 0x5000 0x1000 >;
interrupts = < 0x5 0x1 >;
status = "okay";
label = "CLOCK";
};
power: power@5000 {
compatible = "nordic,nrf-power";
reg = < 0x5000 0x1000 >;
interrupts = < 0x5 0x1 >;
status = "okay";
};
wdt: wdt0: watchdog@18000 {
compatible = "nordic,nrf-watchdog";
reg = < 0x18000 0x1000 >;
interrupts = < 0x18 0x1 >;
status = "okay";
label = "WDT";
};
timer0: timer@f000 {
compatible = "nordic,nrf-timer";
status = "okay";
reg = < 0xf000 0x1000 >;
interrupts = < 0xf 0x1 >;
prescaler = < 0x0 >;
label = "TIMER_0";
};
timer1: timer@10000 {
compatible = "nordic,nrf-timer";
status = "okay";
reg = < 0x10000 0x1000 >;
interrupts = < 0x10 0x1 >;
prescaler = < 0x0 >;
label = "TIMER_1";
};
timer2: timer@11000 {
compatible = "nordic,nrf-timer";
status = "okay";
reg = < 0x11000 0x1000 >;
interrupts = < 0x11 0x1 >;
prescaler = < 0x0 >;
label = "TIMER_2";
};
};
gpiote: gpiote@40031000 {
compatible = "nordic,nrf-gpiote";
reg = < 0x40031000 0x1000 >;
interrupts = < 0x31 0x5 >;
status = "okay";
label = "GPIOTE_1";
};
cryptocell_sw: cryptocell-sw {
compatible = "nordic,nrf-cc310-sw";
#address-cells = < 0x0 >;
label = "CRYPTOCELL_SW";
};
};
cpus {
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
cpu@0 {
device_type = "cpu";
compatible = "arm,cortex-m33f";
reg = < 0x0 >;
#address-cells = < 0x1 >;
#size-cells = < 0x1 >;
mpu: mpu@e000ed90 {
compatible = "arm,armv8m-mpu";
reg = < 0xe000ed90 0x40 >;
arm,num-mpu-regions = < 0x10 >;
};
};
};
buttons {
compatible = "gpio-keys";
button0: button_0 {
gpios = < &gpio0 0x1a 0x11 >;
label = "Button 1";
};
};
leds {
compatible = "gpio-leds";
red_led: led_1 {
gpios = < &gpio0 0x1d 0x0 >;
label = "RGB red channel";
};
green_led: led_2 {
gpios = < &gpio0 0x1e 0x0 >;
label = "RGB green channel";
};
blue_led: led_3 {
gpios = < &gpio0 0x1f 0x0 >;
label = "RGB blue channel";
};
sense_red_led: led_4 {
gpios = < &gpio0 0x0 0x0 >;
label = "RGB red channel";
};
sense_green_led: led_5 {
gpios = < &gpio0 0x1 0x0 >;
label = "RGB green channel";
};
sense_blue_led: led_6 {
gpios = < &gpio0 0x2 0x0 >;
label = "RGB blue channel";
};
};
sram0_bsd: memory@20010000 {
device_type = "memory";
compatible = "mmio-sram";
reg = < 0x20010000 0x10000 >;
};
sram0_ns: memory@20020000 {
device_type = "memory";
compatible = "mmio-sram";
reg = < 0x20020000 0x20000 >;
};
};
For what I can see, spi3 is in "okay" state, so if we found how to disable it, then it may be possible to use the pins as GPIO. I will try again to redirect the sck pin to another place and confirm my change with this file. I don't understand why that wouldn't work.
We almost got this Karl!
Aleix.
Hey Karl!
Wondering on the idea of disabling the SPI I found this post. Where they directly modified the SPI registers to disable it. After doing this I was able to control the SCK as a regular GPIO! I proved that this piece of code did the change, without having to make any change on the prj.conf or the .overlay files:
void disable_spi() {
NRF_SPIM3_NS->TASKS_STOP = 1;
NRF_SPIM3_NS->ENABLE = 0; // To disable SPI3
NRF_SPIM3_NS->PSEL.SCK = 0xFFFFFFFF;
NRF_SPIM3_NS->PSEL.MISO = 0xFFFFFFFF;
NRF_SPIM3_NS->PSEL.MOSI = 0xFFFFFFFF;
NRF_P0_NS->OUTCLR = (1 << 3); // P0.03 (SCK)
NRF_P0_NS->OUTCLR = (1 << 5); // P0.05 (MISO)
NRF_P0_NS->OUTCLR = (1 << 4); // P0.04 (MOSI)
}
Thanks for your help Karl!
Aleix.
Hello again Aleix,
Krawlow said:This information is very useful, but we can't consider this approach at the moment, because a cable to P0.10 would be easier to solder. Also, the advantage of having a test point at the top is that we can use pins with springs to connect to them, but that wouldn't be possible with half of a solder bridge, unfortunately.
Yes, in my rush to find spare possible extra GPIO's I forgot to mention this inconvenience, my apologies. I do not think that soldering onto the cut solder-bridge should prove too much of a challenge, but I concur about the advantages to using a testpoint on top instead.
Krawlow said:We would much rather achieve this solution. Prior to creating this thread, all I did was try to "disabling" it just like you proposed me before, but got the same error.
You changed the status of the spi3 to "disabled" like I wrote earlier, and received the error you posted in the screenshot?
Krawlow said:For what I can see, spi3 is in "okay" state, so if we found how to disable it, then it may be possible to use the pins as GPIO. I will try again to redirect the sck pin to another place and confirm my change with this file. I don't understand why that wouldn't work.
Could you attempt to just disable it - no need to redirect the pins. You might even remove the lines about the spi3 pins at all.
The error you posted in your screenshot seems to stem from the definition of either CONFIG_NRFX_SPI* or CONFIG_SPI_* present somewhere in your configuration. Could you ensure that you have not left this config defined after disabling the SPI?
Krawlow said:Tried to confirm if the SPI was disabled or not by having a look on the builded .dts file. I assumed it was already disabled because I think everything is unless you activate it by adding the corresponding CONFIG inside prj.conf.
This is indeed usually the case, but the Thingy:91 has many things activated out-of-the-box to make prototyping easier.
By the way, the filename of the overlay file needs to match what you are compiling for, so if you are compiling a non-secure Thingy:91 build then the .overlay file name will typically be thingy91_nrf9160ns.overlay. There can not be a discrepancy.
Best regards,
Karl
Hello Aleix,
It appears that I unfortunately did not see your reply while writing my previous comment.
Krawlow said:After doing this I was able to control the SCK as a regular GPIO! I proved that this piece of code did the change, without having to make any change on the prj.conf or the .overlay files:
I am happy to hear that you were able to take control of the pins without making changes to the prj.conf or .overlay file!
This is a good solution in your case.
Krawlow said:Thanks for your help Karl!
No problem at all, I am happy to help!
Please do not hesitate to let me know if you should encounter any other issues or questions in the future.
Best regards,
Karl