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Last activity 2017-12-14 11:04:55 +0200 by Martin Børs-Lind flag of Norway

Behavior when a single PPI channel triggers 2 timer tasks

nRF52832 / SDK 14.2 / SD5.1.0

There might be two configurations to setup a PPI channel to assign some peripheral event to both timer capture & clear task:

1.

nrf_drv_ppi_channel_assign(event, (uint32_t)&NRF_TIMERX->TASKS_CAPTURE[Y]);
nrf_drv_ppi_channel_fork_assign(event, (uint32_t)&NRF_TIMERX->TASKS_CLEAR ...
(more)

81
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no
votes
1
answer
Last activity 2017-12-07 12:21:49 +0200 by Martin Børs-Lind flag of Norway

How to trigger ADC from a timer interrupt, while generating PWM with the same timer and while using BLE on nRF51822?

Hi. I am a newbie in Nordic chips, quite knowledgeable in Atmel AVR, though. I'm working with an nRF51822 on a board like this https://www.waveshare.com/wiki/BLE400. I use the Mbed environment.

What I'm trying ... (more)

63
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1
vote
1
answer
Last activity 2017-12-06 14:36:30 +0200 by Torbjørn Øvrebekk

Just getting started with Tasks and Events: PWM => SAADC

Coming from other embedded systems, I'm impressed with the flexibility and power of the Task/Event framework of the nRF52832. But with great flexibility comes great confusion! :)

I'd like to do something along these lines, written here in ... (more)

142
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2
votes
1
answer
Last activity 2017-11-30 16:06:20 +0200 by Cedric

Parallel time-stamps of GPIO edges with PPI? (timer capture) [closed]

Hi, all!

Is it really possible to timestamp 4 GPIO edges in parallel with the nRF52?

It would need to be as fast as possible and some edges might be simultaneous so PPI seems to be the trick.

The documentations ... (more)

42
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1
vote
1
answer
Last activity 2017-11-23 16:17:16 +0200 by Martin Børs-Lind flag of Norway

GPIOTE event is not triggered sometimes

Hello,

I need two signals with a phase shift to control my motor. For some reason, completely randomly, sometimes my GPIOTE event is not triggered and i get the inversion of the signals. I am spinning the motor for approximately ... (more)

79
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1
vote
1
answer
Last activity 2017-10-28 19:05:51 +0200 by fernandolns

Can I use app_timer and nrf_drv_timer together?

Hi,

I am having problems with using BLE along with gpiote and ppi for measuring the delay between two waveforms and sending the delay between them to an app using bluetooth. I am measuring the delay using the nrf timer ... (more)

87
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3
votes
1
answer
Last activity 2017-10-16 13:47:41 +0200 by Martin Børs-Lind flag of Norway

extra current in idle ~450 uA NRF52832

Hi all

I'm trying to build a generator based on NRF52832. Outpit signals are: 8MHz clock and two latches signals highly sinchronized with clock - RGB_LAT and TXT_LAT. For this task I used TIMER1, PPI and GPIOTE. Actually my approach ... (more)

42
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no
votes
1
answer
Last activity 2017-10-11 16:19:28 +0100 by rom

Problems with PPI groups + S132

I have problem with PPI on NRF52832 (SDK 13.1.0, softdevice S132 4.0.2).

  1. Programmable peripheral interconnect (PPI) usage by Softdevice S132 according to infocenter.
  2. Reservation of PPI is defined in components/softdevice/s132/headers/nrf_sd_def.h. There ...
(more)

107
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3
votes
1
answer
Last activity 2017-10-02 09:07:04 +0200 by Martin Børs-Lind flag of Norway

TIMER_TASKS_START increases power consumption when TWI is in use from 13uA to 450uA

Hi, i would like to implement a very low power counter and used the template from this post. I've modified the example and used TIMER2 in counter mode triggered by LPCOMP through PPI. This worked fine and results in ... (more)

2k
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1
vote
6
answers
Last activity 2017-09-28 08:24:33 +0200 by Yashur

How to output 32768Hz external crystal LFCLK at a GPIO pin?

For synchronizing an external sensor i need to output a 32768Hz clock at a GPIO pin. For this case i want to use LFCLK from the external cyrstal.

<u>My setup:</u> I use RTC0 to generate a tick event ... (more)

61
views
no
votes
1
answer
Last activity 2017-09-15 09:29:44 +0200 by Martin Børs-Lind flag of Norway

Why isn't my PPI/SPI channel triggered with GPIOTE?

Hello,

I would like to detect a change in a pin(GPIO_IN_NUMBER) and depending on it I would like to trigger a SPI transaction, this should happen through PPI.

So far I have configured my PPI in this way, is ... (more)

85
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no
votes
no
answers
Last activity 2017-09-11 10:39:24 +0200 by ndarkness

Why is not my Timer triggered when configured through PPI and SPI?

Hello,

I am trying to use ArrayList for EasyDMA along with PPI but I am not sure whether or not I am configuring it properly to be used with the SPI interface.

So far I have set it up as ... (more)

145
views
no
votes
1
answer
Last activity 2017-09-07 16:00:16 +0200 by Turbo J

Can I get data from an external ADC without using CPU time?

Hello,

I would like to make use of an external ADC that is connected to my nRF52832 through SPI & easyDMA,minimizing the use of the CPU (or without using the CPU).

The sampling frequency, when nRF52832 will request a sample ... (more)

200
views
1
vote
1
answer
Last activity 2017-08-25 12:30:17 +0100 by Petter Myhre flag of Norway

Found a Bug in the PPI Example

Hi, I found a bug in the PPI example in the nRF5 SDK v14.0.0 .

In "<SDK_ROOT>/examples/peripheral/ppi/main.c", the following function has an error:

static void timer2_init(void)
{
    // Generate interrupt/event when half of time ...
(more)

83
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no
votes
1
answer
Last activity 2017-08-14 12:43:33 +0200 by flip-flop flag of Croatia

PWM on nrf52 with mbed consumes to much current.

Hi, I wonder why my pwm uses so much power in WFI mode. It uses around 470uA and when I do not use pwm that current is around 1.8uA. I tried to disable pwm but without success. Here's ... (more)

109
views
3
votes
1
answer
Last activity 2017-06-18 23:54:07 +0100 by endnode

Radio Notification and PPI

Hi,

If I configure the radio notification to ACTIVE and then set a DISTANCE of 800us, is there any way that I can configure PPI to toggle a pin for example?

I know that I can just do the toggle ... (more)

152
views
no
votes
1
answer
Last activity 2017-06-15 12:58:08 +0200 by Jørgen Holmefjord flag of Norway

saadc problem

Hi,I use demo project in

nRF5_SDK_12.1.0_0d23e2a\examples\peripheral\saadc\pca10040\blank\arm5_no_packs\saadc_pca10040.uvprojx.

I made the following changes: 1.add one saadc input 2.channel 0 is connected to VDD,and channel 1 is connected to ... (more)

73
views
1
vote
1
answer
Last activity 2017-06-14 12:33:04 +0200 by Daniel T. Lee flag of Korea, Republic of

Is there any way that I can use more than 3 timer in nRF 51 ??

Is there any way that I can use more than 4 timer in nRF 51 ?? (four or more...)

I'm using Softdevice 130, so It uses Timer 0,

and I'm using RGB Sensor using PWM Library, and

Red and ... (more)

527
views
1
vote
2
answers
Last activity 2017-04-03 11:32:44 +0200 by PrithviRaj Narendra flag of India

SAADC low power scan mode

Greetings,

I have a setup where I have a periodic single channel low power SAADC implementation. In this the configuration is

  • A single SAADC channel is initialized (10 us acquisition time, differential, gain 4, 12 bit, internal reference)
  • RESULT.MAXCNT ...
(more)

445
views
1
vote
1
answer
Last activity 2017-03-20 09:44:11 +0200 by Wojtek flag of Poland

nrf52 PPI+EasyDMA using timer and SPI

Hi,

I am using nrf52832 for my application. The application share same SPI module for two sensors(with sensors are selected using two chip select pins). Is it possible to implement PPI channel between a timer and this SPI module ... (more)

163
views
1
vote
1
answer
Last activity 2017-03-05 00:22:44 +0200 by Robert Massaioli

ADC + PPI + Timer on the nRF51822 polling too fast

I have the following ADC code: https://bitbucket.org/snippets/robert...

I have been trying for the past few days to get this code to just perform a single ADC scan, on five channels, once every 100ms.

It seems like ... (more)

199
views
6
votes
1
answer
Last activity 2017-03-04 12:07:47 +0100 by Aryan flag of Norway

ppi clearing of event flag

Hi, Does the PPI module automatically clear the event flags for the linked event? For example, if I have the following:

NRF_PPI->CH[0].EEP = (uint32_t)&(NRF_GPIOTE->EVENTS_IN[0]);
NRF_PPI->CH[0].TEP =(uint32_t) &(NRF_TIMER1->TASKS_CLEAR);
NRF_PPI->FORK[0].TEP ...
(more)

222
views
2
votes
1
answer
Last activity 2017-02-20 14:34:10 +0200 by Jørgen Holmefjord flag of Norway

ADC / PPI: SDK v11.0.0 works but v12.2.0 does not

I was building my own custom application that connects a nrf_drv_timer to an ADC start trigger using PPI on an nRF51822 and I could not get it to work. I asked a previous question about it here. This is a ... (more)

129
views
1
vote
1
answer
Last activity 2017-02-16 17:18:18 +0200 by wizath

gpiote sense high frequency signal

Hi,

I want to implement simple module: 1) gpiote event on pin change (around 6.7MHz signal) 2) Route gpiote event through PPI to increment counter 3) Toggle GPIO pin on Compare event

Im using this code (modified example of ... (more)

196
views
2
votes
2
answers
Last activity 2017-02-02 12:21:29 +0100 by Stian flag of Norway

Turning SPI peripheral on/off from PPI

I have an application working using PPI to start a SPI master transaction from a GPIOTE event. Unfortunately, I currently have very high current consumption which I am led to believe is because the SPI peripheral is always enabled. Can ... (more)

379
views
no
votes
no
answers
Last activity 2017-01-26 14:22:18 +0200 by Pascal Künzi

Delay from GPIOTE Event until a Task is started over PPi on nRF52

Hi all,

I measured the delays between a GPIOTE event and a Task (in this case toggling with another GPIOTE) through PPI. image description

The results are showed below: image description

For the nRF52 it's arround 380ns.

The same measurements were done with ... (more)

207
views
no
votes
1
answer
Last activity 2017-01-24 16:49:12 +0200 by Stian flag of Norway

Reducing TWI Active Current

Hello,

I am currently working on an ultra-low power project that requires reading an I2C accelerometer multiple times per second. After analyzing the current consumption in the design, it is clear that the TWI peripheral uses quite a bit of ... (more)

116
views
5
votes
1
answer
Last activity 2017-01-24 02:17:20 +0200 by Rusty Scott

No slave select on SPIM xfer using PPI and GPIOTE

I have a custom board that has an MPU9250 attached as a SPI device. The MPU can generate data ready interrupts. I have set the MPU to generate data ready 4x per second which is about the slowest it can ... (more)

411
views
4
votes
2
answers
Last activity 2017-01-23 03:02:54 +0200 by Emil Lenngren flag of Sweden

why should I clear event in the interrupt handler

as far as I am concerned, when I use PPI or SHORTS without interrupts, I DON'T need to clear the corresponding event registers, and task will be triggered once the event is generated. But when I enable interrupt, I ... (more)

292
views
no
votes
1
answer
Last activity 2017-01-16 10:40:38 +0200 by haakonsh

nrf_drv_gpiote_in_event_enable does not work as expected

Hello, we need to first enable GPIOTE+IRQ. Then after 1st IRQ we want to keep only GPIOTE and disable IRQ. We do not want to disable GPIOTE (because it works with PPI), but only to disable IRQ.

We tried ... (more)

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