How to make a simple LED blink program

RE: How to make a simple LED blink program

Sigurd — Wed, 10 May 2017 13:14:04 GMT

Hi t,

In order to blink the led in the blinky example, the pin that is connect to the led is set high(VDD voltage) and low(0 voltage). By default the example changes between high and low state every 500ms. If you have more questions please create new question.

RE: How to make a simple LED blink program

Wed, 10 May 2017 12:05:55 GMT

can anyone explain how led is blinking ?

RE: How to make a simple LED blink program

Sigurd — Tue, 14 Feb 2017 09:45:42 GMT

For beginners I would recommend using the pwm library, since it’s not as complicated as the pwm driver.

There is a good example in SDK_folder\examples\peripheral\pwm_library. The period will depend on the frequency(frequency = 1 /period). If you look at the example, the period is configured using APP_PWM_DEFAULT_CONFIG_2CH() / APP_PWM_DEFAULT_CONFIG_1CH(). The duty cycle is set using the function app_pwm_channel_duty_set().

RE: How to make a simple LED blink program

akshaey — Tue, 14 Feb 2017 09:15:42 GMT

i know i have been asking you a lot of questions, but please help me as i am new and want to learn and implement on nr52. i got to know from other posts that using the pwm_driver is recommended as nrf52 has an inbuilt pwm hardware. But which parameters to modify in the code to change the DUTY_CYCLE, Total_Cycle period, Pwm frquency as in the code there are parmeters which i found like the following--

typedef struct { uint16_t channel_0; ///< Duty cycle value for channel 0. uint16_t channel_1; ///< Duty cycle value for channel 1. uint16_t channel_2; ///< Duty cycle value for channel 2. uint16_t channel_3; ///< Duty cycle value for channel 3. } nrf_pwm_values_individual_t;

typedef enum { NRF_PWM_CLK_16MHz = PWM_PRESCALER_PRESCALER_DIV_1, ///< 16 MHz / 1 = 16 MHz. NRF_PWM_CLK_8MHz = PWM_PRESCALER_PRESCALER_DIV_2, ///< 16 MHz / 2 = 8 MHz. NRF_PWM_CLK_4MHz = PWM_PRESCALER_PRESCALER_DIV_4, ///< 16 MHz / 4 = 4 MHz. NRF_PWM_CLK_2MHz = PWM_PRESCALER_PRESCALER_DIV_8, ///< 16 MHz / 8 = 2 MHz. NRF_PWM_CLK_1MHz = PWM_PRESCALER_PRESCALER_DIV_16, ///< 16 MHz / 16 = 1 MHz. NRF_PWM_CLK_500kHz = PWM_PRESCALER_PRESCALER_DIV_32, ///< 16 MHz / 32 = 500 kHz. NRF_PWM_CLK_250kHz = PWM_PRESCALER_PRESCALER_DIV_64, ///< 16 MHz / 64 = 250 kHz. NRF_PWM_CLK_125kHz = PWM_PRESCALER_PRESCALER_DIV_128 ///< 16 MHz / 128 = 125 kHz. } nrf_pwm_clk_t;

RE: How to make a simple LED blink program

akshaey — Mon, 13 Feb 2017 13:36:46 GMT

thanks for your reply, i will try changing that in the code, also i want to implement a simple pwm generator where i can give just 3 inputs, one for DUTY CYCLE, one for TOTAL CYCLE PERIOD VALUE, and one for PWM frequency. The example codes for pwm_library and pwm_driver are really lengthy/long including there header files and functions. Can i somehow implement a simple small pwm program on nrf52 as on other devices like PIC, AVR or 8051.
thanks for your help

RE: How to make a simple LED blink program

Sigurd — Mon, 13 Feb 2017 13:11:31 GMT

The UART toolbox app interpret the values as characters/string, so you have to convert the numbers to char/string if you want them displayed "correctly" in the app.

RE: How to make a simple LED blink program

akshaey — Fri, 10 Feb 2017 10:53:26 GMT

on sdk11, its working but in the UART on nrf toolbox app on my phone it is receiving random garbage values via bluetooth, although on my pc in uart terminal , its showing the correct values. how to solve this? thanks

RE: How to make a simple LED blink program

Sigurd — Fri, 10 Feb 2017 10:09:36 GMT

That example uses SDK 11, so you have to download SDK11 instead of SDK12.2. Then make sure that the folder "ble_app_uart__saadc_timer_driven__scan_mode" is placed in the folder "SDK_11_FOLDER\examples\ble_peripheral". I.e "SDK_11_FOLDER\examples\ble_peripheral\ble_app_uart__saadc_timer_driven__scan_mode"

RE: How to make a simple LED blink program

akshaey — Fri, 10 Feb 2017 10:04:24 GMT

i tried this example given on this thread( github.com/.../main.c ) for ble+saadc, but i don't know why it gives the following error -

compiling ble_nus.c... "no source": Error: #5: cannot open source input file "............\components\ble\ble_services\ble_nus\ble_nus.c": No such file or directory ............\components\ble\ble_services\ble_nus\ble_nus.c: 0 warnings, 1 error compiling bsp.c... "no source": Error: #5: cannot open source input file "..........\bsp\bsp.c": No such file or directory ..........\bsp\bsp.c: 0 warnings, 1 error compiling ble_advdata.c... "no source": Error: #5: cannot open source input file "............\components\ble\common\ble_advdata.c": No such file or directory ............\components\ble\common\ble_advdata.c: 0 warnings, 1 error compiling ble_advertising.c... "no source": Error: #5: cannot open source input file "............\components\ble\ble_advertising\ble_advertising.c": No such file or directory ............\components\ble\ble_advertising\ble_advertising.c: 0 warnings, 1 error compiling main.c... ......\main.c(28): error: #5: cannot open source input file "nordic_common.h": No such file or directory #include "nordic_common.h" ......\main.c: 0 warnings, 1 error compiling bsp_btn_ble.c... "no source": Error: #5: cannot open source input file "..........\bsp\bsp_btn_ble.c": No such file or directory ..........\bsp\bsp_btn_ble.c: 0 warnings, 1 error compiling ble_conn_params.c... "no source": Error: #5: cannot open source input file "............\components\ble\common\ble_conn_params.c": No such file or directory ............\components\ble\common\ble_conn_params.c: 0 warnings, 1 error compiling nrf_drv_uart.c... "no source": Error: #5: cannot open source input file "............\components\drivers_nrf\uart\nrf_drv_uart.c": No such file or directory ............\components\drivers_nrf\uart\nrf_drv_uart.c: 0 warnings, 1 error compiling ble_srv_common.c... "no source": Error: #5: cannot open source input file "............\components\ble\common\ble_srv_common.c": No such file or directory ............\components\ble\common\ble_srv_common.c: 0 warnings, 1 error compiling pstorage.c... "no source": Error: #5: cannot open source input file "............\components\drivers_nrf\pstorage\pstorage.c": No such file or directory ............\components\drivers_nrf\pstorage\pstorage.c: 0 warnings, 1 error compiling nrf_drv_common.c... "no source": Error: #5: cannot open source input file "............\components\drivers_nrf\common\nrf_drv_common.c": No such file or directory ............\components\drivers_nrf\common\nrf_drv_common.c: 0 warnings, 1 error compiling nrf_drv_gpiote.c... "no source": Error: #5: cannot open source input file "............\components\drivers_nrf\gpiote\nrf_drv_gpiote.c": No such file or directory ............\components\drivers_nrf\gpiote\nrf_drv_gpiote.c: 0 warnings, 1 error compiling nrf_delay.c... "no source": Error: #5: cannot open source input file "............\components\drivers_nrf\delay\nrf_delay.c": No such file or directory ............\components\drivers_nrf\delay\nrf_delay.c: 0 warnings, 1 error compiling app_uart_fifo.c... "no source": Error: #5: cannot open source input file "............\components\libraries\uart\app_uart_fifo.c": No such file or directory ............\components\libraries\uart\app_uart_fifo.c: 0 warnings, 1 error compiling nrf_drv_ppi.c... "no source": Error: #5: cannot open source input file "............\components\drivers_nrf\ppi\nrf_drv_ppi.c": No such file or directory ............\components\drivers_nrf\ppi\nrf_drv_ppi.c: 0 warnings, 1 error compiling app_button.c... "no source": Error: #5: cannot open source input file "............\components\libraries\button\app_button.c": No such file or directory ............\components\libraries\button\app_button.c: 0 warnings, 1 error compiling nrf_drv_timer.c... "no source": Error: #5: cannot open source input file "............\components\drivers_nrf\timer\nrf_drv_timer.c": No such file or directory ............\components\drivers_nrf\timer\nrf_drv_timer.c: 0 warnings, 1 error compiling app_error.c... "no source": Error: #5: cannot open source input file "............\components\libraries\util\app_error.c": No such file or directory ............\components\libraries\util\app_error.c: 0 warnings, 1 error compiling app_error_weak.c... "no source": Error: #5: cannot open source input file "............\components\libraries\util\app_error_weak.c": No such file or directory ............\components\libraries\util\app_error_weak.c: 0 warnings, 1 error compiling nrf_saadc.c... "no source": Error: #5: cannot open source input file "............\components\drivers_nrf\hal\nrf_saadc.c": No such file or directory ............\components\drivers_nrf\hal\nrf_saadc.c: 0 warnings, 1 error compiling nrf_drv_saadc.c... "no source": Error: #5: cannot open source input file "............\components\drivers_nrf\saadc\nrf_drv_saadc.c": No such file or directory ............\components\drivers_nrf\saadc\nrf_drv_saadc.c: 0 warnings, 1 error compiling app_fifo.c... "no source": Error: #5: cannot open source input file "............\components\libraries\fifo\app_fifo.c": No such file or directory ............\components\libraries\fifo\app_fifo.c: 0 warnings, 1 error compiling app_timer.c... "no source": Error: #5: cannot open source input file "............\components\libraries\timer\app_timer.c": No such file or directory ............\components\libraries\timer\app_timer.c: 0 warnings, 1 error compiling fstorage.c... "no source": Error: #5: cannot open source input file "............\components\libraries\fstorage\fstorage.c": No such file or directory ............\components\libraries\fstorage\fstorage.c: 0 warnings, 1 error compiling retarget.c... "no source": Error: #5: cannot open source input file "............\components\libraries\uart\retarget.c": No such file or directory ............\components\libraries\uart\retarget.c: 0 warnings, 1 error compiling app_util_platform.c... "no source": Error: #5: cannot open source input file "............\components\libraries\util\app_util_platform.c": No such file or directory ............\components\libraries\util\app_util_platform.c: 0 warnings, 1 error compiling nrf_assert.c... "no source": Error: #5: cannot open source input file "............\components\libraries\util\nrf_assert.c": No such file or directory ............\components\libraries\util\nrf_assert.c: 0 warnings, 1 error compiling nrf_log.c... "no source": Error: #5: cannot open source input file "............\components\libraries\util\nrf_log.c": No such file or directory ............\components\libraries\util\nrf_log.c: 0 warnings, 1 error compiling RTT_Syscalls_KEIL.c... "no source": Error: #5: cannot open source input file "............\external\segger_rtt\RTT_Syscalls_KEIL.c": No such file or directory ............\external\segger_rtt\RTT_Syscalls_KEIL.c: 0 warnings, 1 error compiling SEGGER_RTT.c... "no source": Error: #5: cannot open source input file "............\external\segger_rtt\SEGGER_RTT.c": No such file or directory ............\external\segger_rtt\SEGGER_RTT.c: 0 warnings, 1 error compiling SEGGER_RTT_printf.c... "no source": Error: #5: cannot open source input file "............\external\segger_rtt\SEGGER_RTT_printf.c": No such file or directory ............\external\segger_rtt\SEGGER_RTT_printf.c: 0 warnings, 1 error compiling softdevice_handler.c... "no source": Error: #5: cannot open source input file "............\components\softdevice\common\softdevice_handler\softdevice_handler.c": No such file or directory ............\components\softdevice\common\softdevice_handler\softdevice_handler.c: 0 warnings, 1 error assembling arm_startup_nrf52.s... compiling system_nrf52.c... "._build\nrf52832_xxaa_s132.axf" - 1 Error(s), 0 Warning(s). Target not created. Build Time Elapsed: 00:00:02

RE: How to make a simple LED blink program

Sigurd — Fri, 10 Feb 2017 09:37:22 GMT

If you want to do SAADC with BLE, I recommend starting with the ble_app_uart example, and add SAADC to that example.

RE: How to make a simple LED blink program

Sigurd — Fri, 10 Feb 2017 09:35:42 GMT

Modify uint32_t ticks = nrf_drv_timer_ms_to_ticks(&m_timer, 400); to increase the sampling interval. Default compare event time is 400ms. Adjust #define SAMPLES_IN_BUFFER 5, for how many samples for each event.

RE: How to make a simple LED blink program

akshaey — Fri, 10 Feb 2017 09:17:45 GMT

And how to adjust the flash settings in keil so that the code doesn't overlasps with softdevice address? As i want to transmit the data of saadc via BLE (as then i need to use a softdevice for bluetooth but saadc example doesn't supports softdevice).

thanks for your help

RE: How to make a simple LED blink program

akshaey — Thu, 09 Feb 2017 17:43:44 GMT

In SAADC , how to change the sampling frequency? which code to modify and where?

RE: How to make a simple LED blink program

Sigurd — Thu, 09 Feb 2017 14:27:08 GMT

The blank examples are set-up to flash the application code(your code in Keil) to the bottom of the flash-region, while the s132 examples are set-up to flash the application code on top of where the SoftDevice code is(The SoftDevice is always placed on the bottom of the flash-region). See this figure.

If you want to flash “blank” examples together with the SoftDevice, you must adjust the flash settings in Keil, so that you don’t try to flash your application code where the SoftDevice code is (then you get Flash download failed error.).

For ADC, take a look at the SAADC example in the SDK: examples\peripheral\saadc. Here AIN0 is used(pin P0.02). This example is already set-up to output the value on a terminal.

RE: How to make a simple LED blink program

akshaey — Thu, 09 Feb 2017 13:45:33 GMT

thanks , yes it works if i erase the softdevice but what is the reason for that? a softdevice was even used in a blinky software which doesn't uses any wireless technology , but why it is not used in pwm? i thought it was only there for using wireless services.

Also if i want to use the ADC, how can i modify the example code to get an output on the terminal if i give a sample analog value on the AnalogIN.

thanks for all your help

RE: How to make a simple LED blink program

Sigurd — Wed, 08 Feb 2017 16:28:02 GMT

For projects/examples located in "blank folder", e.g. pca10040\blank, you should not use SoftDevice. You only need the S132 SoftDevice in the projects located in a “pca10040\s132” folder. E.g. the pwm example does not use the SoftDevice, and is thefore loacted in a "blank" folder: examples\peripheral\pwm_library\pca10040\ blank \arm5_no_packs

RE: How to make a simple LED blink program

akshaey — Wed, 08 Feb 2017 15:27:48 GMT

i had already loaded the softdevice s132 via command line in the beginning when i tried the blinky example, which is still working, and it still shows an option for flash softdevice in drop down menue besides LOAD,

however, when i try to run the pwm example, it does'nt shows any flash_132 softdevice option in the drop down menu.

How to load softdevice from keil for each example i try? in the tutorial it says to do the following but it doesn't works

To program the SoftDevice using an example project in Keil, perform the following steps:

. Instead of the default target, select the target to flash the SoftDevice, for example, flash_s132_nrf52_1.0.0-3.alpha_softdevice. Click Options for Target. Select the Debug pane and click the Settings button for the J-Link / J-TRACE Cortex. Select J-Link / J-Trace Adapter corresponding to the serial number that is printed on your device. Click OK

RE: How to make a simple LED blink program

Sigurd — Wed, 08 Feb 2017 13:53:24 GMT

Have you loaded the SoftDevice? If you try to overwrite the SoftDevice, this can cause the Flash Download failed message. Try to erase the chip, and then flash the application.

Here is the GPIO functions. Configure the gpio pin as output, using nrf_gpio_cfg_output() and use nrf_gpio_pin_set() to set the pin high, and nrf_gpio_pin_clear() to set the pin low.

RE: How to make a simple LED blink program

akshaey — Wed, 08 Feb 2017 13:19:20 GMT

thanks but

when i try to flash this example , it says

Error: Flash Download Failed - "Cortex - M4"

How to solve this?

Also please just let me know which command to use to configure any GPIO pin as a output and then set/reset it so that i can use the above logic to generate a square wave on any choosen gpio pin.

thanks for your help

RE: How to make a simple LED blink program

Sigurd — Wed, 08 Feb 2017 12:40:29 GMT

For PWM I strongly recommend to use either the PWM library or the PWM driver. Take a look at the PWM library example:

SDK_FOLDER\examples\peripheral\pwm_library\pca10040\blank\arm5_no_packs

RE: How to make a simple LED blink program

akshaey — Wed, 08 Feb 2017 12:33:30 GMT

i have been able to blink led with the following code, but how to use this code to generate a PWM on any other GPIO pins than the 4 LED pins given. which command to be used for setting a pin low or high?

include <stdbool.h>

include <stdint.h>

include "nrf_delay.h"

include "bsp.h" /for gpio and led declrtn/

include "nrf.h"

include "system_nrf52.h"

define ENABLE_SWD 1

static const uint8_t leds_list[LEDS_NUMBER] = { 9, 7, LED_1, LED_4 };

int main(void) { /* Configure LED-pins as outputs. */ LEDS_CONFIGURE(LEDS_MASK); int i=0;

while(true) { while(i<500)

{

                         // Start LED here

nrf_gpio_pin_clear(LED_3);

nrf_delay_ms(1000);

nrf_gpio_pin_set(LED_3);

nrf_delay_ms(1000);

                        i++;

                    }

} }

RE: How to make a simple LED blink program

Sigurd — Wed, 08 Feb 2017 11:32:03 GMT

In that case I would recommend starting with the template project:

SDK_Folder\examples\peripheral\template_project\pca10040\blank\arm5_no_packs

You can find example on how to use the GPIO peripheral directly here. Pin 17 is the LED1 on the Development kit(DK).

RE: How to make a simple LED blink program

akshaey — Wed, 08 Feb 2017 11:02:19 GMT

thanks for your reply,

i used the blinky program and i saw that it uses built in library functions but what if i want to create a program from scratch or the beginning without using any built in function, by coding in C to just set and reset a pin on nrf52832 after a delay?

thanks

RE: How to make a simple LED blink program

Sigurd — Wed, 08 Feb 2017 09:43:34 GMT

Use the Keil project in the folder

<SDK_InstallFolder>\examples\peripheral\blinky\pca10040\blank\arm5_no_packs

RE: How to make a simple LED blink program

Sigurd — Wed, 08 Feb 2017 09:42:08 GMT

Hi,

There is a blinky example in the SDK. Its located in the folder:

<SDK_InstallFolder>\examples\peripheral\blinky

You can download the SDK 12.2 here.