saadc example

RE: saadc example

MikeLemon — Sun, 05 Nov 2017 17:25:50 GMT

Hi there sorry for digging the car from the grave but when I run this example and short the P0.02 or P0.03 to ground the result won't change from 2.8xxx any idea why?

RE: saadc example

Jørgen Holmefjord — Tue, 18 Apr 2017 12:26:36 GMT

The default setting in the SAADC example is to use internal reference (0.6V) and P0.02/AIN0. Have you changed any of the settings in the example?

RE: saadc example

Waqar Ahmed — Thu, 13 Apr 2017 11:57:31 GMT

need your help JORGEN

RE: saadc example

Waqar Ahmed — Thu, 13 Apr 2017 07:33:22 GMT

is p0.02 is analog reference ??,i think p0.02 on dk is analog reference .if i give analog postive at p0.04 and negative to at analog reference pin at p0.02.its show postive value.one or two value in buffer of 10 are negative.is this is correct way???

RE: saadc example

Waqar Ahmed — Thu, 13 Apr 2017 06:06:39 GMT

when i remove analog signal it give postive value at terminal

RE: saadc example

Waqar Ahmed — Thu, 13 Apr 2017 06:04:15 GMT

i have measure the vdd at dk it give almost 2.82v and i give the signal vpp 2v but again it give it negative value.

RE: saadc example

Jørgen Holmefjord — Wed, 12 Apr 2017 12:59:44 GMT

Try measuring the voltage on VDD of your board and set the signal Vpp to a voltage below this. I measure 2.85 V on my nRF52 DK when driven by USB supply.

RE: saadc example

Waqar Ahmed — Wed, 12 Apr 2017 12:55:15 GMT

i have not change any thing in example .this sine signal have peak to peak voltage 3v. and i attach my nrf52dk to laptop

RE: saadc example

Jørgen Holmefjord — Wed, 12 Apr 2017 12:52:59 GMT

What is the supply voltage of your device? Note that the SAADC cannot read analog values above VDD. Also, do you use the settings in the SAADC example? Which sampling rate?

RE: saadc example

Waqar Ahmed — Wed, 12 Apr 2017 12:52:27 GMT

i take sine signal from function generator and attach postive cable to p0.04 and and ground one of function generator to gnd at dk

RE: saadc example

Waqar Ahmed — Wed, 12 Apr 2017 12:49:58 GMT

some thing like this:

APP:INFO:SAMPLES ARE 309
APP:INFO:SAMPLES ARE 436
APP:INFO:SAMPLES ARE -1024
APP:INFO:SAMPLES ARE -1024
APP:INFO:SAMPLES ARE 193
APP:INFO:SAMPLES ARE 490
APP:INFO:SAMPLES ARE 344
APP:INFO:SAMPLES ARE -1024
APP:INFO:SAMPLES ARE -1024
APP:INFO:SAMPLES ARE 100
APP:INFO:ADC event number: 899
APP:INFO:SAMPLES ARE 487
APP:INFO:SAMPLES ARE -341
APP:INFO:SAMPLES ARE -1024
APP:INFO:SAMPLES ARE -1024
APP:INFO:SAMPLES ARE -1024
APP:INFO:SAMPLES ARE -69

RE: saadc example

Jørgen Holmefjord — Wed, 12 Apr 2017 11:57:27 GMT

Only negative values, or are some values slightly negative?

RE: saadc example

Waqar Ahmed — Wed, 12 Apr 2017 10:31:42 GMT

thanks i have apply the sine wave having vpp 3v t analog input p0.04 .but this one shows negative values at putty terminal.

RE: saadc example

Jørgen Holmefjord — Wed, 12 Apr 2017 08:44:51 GMT

In saadc_sampling_event_init(), there is a timer setup to trigger the sample task every 400 ms. You can change the sample rate by changing the second parameter or the call to nrf_drv_timer_ms_to_ticks(&m_timer, 400);.

RE: saadc example

Waqar Ahmed — Wed, 12 Apr 2017 05:59:20 GMT

ok i done it.one more thing ,in this example i want to change sampling rate .can you tell me .how can i change ???.i run saadc example from sdk12.1 .thanks in advance

RE: saadc example

Waqar Ahmed — Tue, 11 Apr 2017 13:30:11 GMT

thanks JORGEN

RE: saadc example

Jørgen Holmefjord — Tue, 11 Apr 2017 11:31:48 GMT

I'm not sure I understand your question. You can use the SAADC to convert an analog signal to a digital value. You connect the external signal to the analog input and then get the output from the sample in terminal.

RE: saadc example

Waqar Ahmed — Tue, 11 Apr 2017 11:27:10 GMT

thanks JORGEN .one more things i want to ask from you how can i give external signal to dk and the convert it digital output .kindly refer me something

RE: saadc example

Jørgen Holmefjord — Tue, 11 Apr 2017 11:11:23 GMT

Hi,

The SAADC example in the SDK is described in the SDK example documentation. As described in the documentation, the example use analog input 0 (GPIO pin 2) to sample analog signal. This is the pin marked P0.02 on the nRF52 DK. There are 8 analog inputs on the nRF52832 (AIN0-AIN7), and you can find the corresponding GPIO pin name in the Pin assignments-section of the product specifications.

Best regards,

Jørgen