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Questions tagged [adc]

Analog Digital converter

0
votes
1answer
26 views

Getting incorrect output from ADC over SPI in Arduino Uno

I am trying to read data from an ADC ADCS7476 (datasheet) using SPI on Arduino Uno. I am using the following code to read the data from the ADC and printing it on serial monitor. However, the code is ...
1
vote
1answer
41 views

Anomalous behaviour of ADC, digitalWrite and floating point operations

I'm trying to analyse mic (A0) input, calculate certain spectral lines with Goertzel algorithm to detect a number encoded by DTFM and display it with 8x8 matrix display (max7219 driver). The code ...
0
votes
1answer
17 views

Running ADC triggered by TIMER1_COMPB

I'm trying to run ADC on channel 0 triggered by TIMER1_COMPB. Everything seem to work ok but basic arithmetics is not working and variables inside ISR and even main loop don't get updated (x == 2 all ...
0
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0answers
11 views

Relay arcing protection for analog input [migrated]

I need to measure the voltage of a Li-ion battery that is connected through a relay, on the NC pin, to the rest of the circuit (so BAT+ - relay - circuit). The coil of the relay is connected to ...
0
votes
1answer
60 views

Trouble configuring Arduino Due SPI to ADC

I am having trouble configuring Arduino Due SPI to an AD7490 ADC. Here is how I have the pins connected: +3.3V > 7490 pin 22 Vin +3.3V > 7490 Vref DUE CS (8) > 7490 pin 20 SS - slave select) DUE ...
0
votes
1answer
32 views

ADC noise when sharing ground from external supplies

i have resistor based sensor, when i test it using arduino connect to PC using serial monitor without sharing ground to other circuit it has a nice value between 300-650 in adc range and the error/ ...
1
vote
1answer
61 views

Arduino Uno ADCH register stuck at 255 when read from ISR

I'm working on a project that will essentially become an oscilloscope in the long run. I am following this guide. My code is uploaded here for more reference. In my .ino file I have called functions ...
0
votes
1answer
39 views

Stacking adc's when making an midi controller ( lots of potmeters)

I'm making a midi controller with the Arduino uno. It contains approximately 50 analog inputs with potentiometers. I have enough MCP3008 adc's here but I have no idea how I connect 2 or more adc's to ...
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0answers
65 views

ESP8266 ADC using battery value measure problem

I try to measure battery value in esp8266 Anagalog pin. 4.2v battery add voltage divide circuit in R1 1Mega R2 320K ADC input voltage 1.06V. ADC output print to serial 4.2v come serial. But i decrease ...
0
votes
1answer
46 views

Due: Write to digital pin when ADC is running

I have a problem writing to a digital pin on Arduino Due while my ADC is running. I have the following code: #undef HID_ENABLED // Arduino Due ADC->DMA->USB 1MSPS // by stimmer // from ...
0
votes
1answer
93 views

Waterlevel sensor disrupts PH reading

I have a water level sensor and a PH sensor connected to my nodemcu via an ADS1115 . When I insert only the PH sensor into the water then everything works fine. But when I insert the waterlevel sensor ...
0
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0answers
43 views

Arduino Mega 2560 Read AC Voltage

I would like to get realy fast ADC readings. I would like to get in 1ms atleast 5 or more measurment. Something like osciloscope but i need this for other application not for osciloskop. Do you ...
0
votes
1answer
33 views

If I use a biasing circuit for a signal going into an analog input pin, will it affect the ADC operation?

If I have a single 100Hz AC signal biased by two 1 M-ohm resistors (as per schematic below), and then output to an Arduino UNO analog input pin, with the UNO sampling at around 1 kHz using delays, ...
4
votes
2answers
301 views

What will happen if I set ARef to 3.3V and try to use adc connected to 5V

What will happen, if I try to measure voltage higher than ARef? For example, my ref is 3.3V, and I try to measure 4.5V. Will it damage adc?
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0answers
61 views

Adding timestamp to data from ADC (Arduino DUE)

I want to read voltages from a resistor and I am using stimmer's method to get 1Msps from the Arduino Due Code can be found here: https://gist.github.com/pklaus/5921022 I just don't really get how I ...
1
vote
2answers
64 views

How to set sampling rate for digital pin input? [closed]

I have an ADC that have sampling rate up to 40 MSPS, but i use 8 MHz clock so it will be 8 MSPS. The board used is arduino nano. The problem is i have to sampling it just 2 MHz (because the capacity ...
0
votes
1answer
50 views

How to decrease adc accuracy?

I read in this atmega328p datasheet the following on page 308: From sect. 28.4: By default, the successive approximation circuitry requires an input clock frequency between 50kHz and 200kHz to ...
0
votes
1answer
156 views

Interaction between Analog Pins when measuring a DC voltage- a common issue? [duplicate]

Just set up a replacement "Piduino" - a RPi3 connected by USB to an Arduino Uno. The previous one was the victim of a Diet Big Gulp - spilled on the voltage divider breadboard. Whoops. The tiny ...
0
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0answers
39 views

Improve low end resolution on DFRobot TDS Kit

I've purchased one of the new DF robot TDS kits for measuring some purified (Reverse Osmosis + DI) water. I'd like to measure between 0 and 10 TDS (only) but can't get a stable enough reading. This ...
0
votes
1answer
91 views

Repairing Analogue Inputs on Uno?

After a long afternoon, chasing a fault on my project, I've come to find that I've damaged 2 out of the 6 Analogue Inputs. Their ADC reading doesn't display 0 when grounded, nor a known ADC value from ...
0
votes
2answers
367 views

Measuring Lithium ion cell voltage used to power Arduino via a boost module

Can I measure lithium ion cell voltage with Arduino ADC which is used to power the same Arduino through a boost module (XL6009)? The output voltage of boost module is 9 volts.
0
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0answers
636 views

ESP8266 ADC read analog

I have a 24CL256 external EEPROM, to which I wish to write 30,000 bytes of 8-bit data, reading from the built-in ADC of an ESP8266. Here is my code: void setup() { Serial.begin(115200); Wire....
1
vote
1answer
590 views

ESP8266: system_adc_read_fast() always give 1024 as output

I need to use system_adc_read_fast (uint16 *adc_addr, uint16 adc_num, uint8 adc_clk_div) to get a sampling rate close to 100ksps. And I am able to achieve that using adc_clk_div = 32. However, when I ...
0
votes
0answers
132 views

interrupt driven ADC with I2C freezes arduino pro mini

In my project I use a pro mini to read 4 analog values. Those values are then passed over I2C to an RPi. So far I have been using analogRead to read in the values, does the job ok. Now I'd like to ...
1
vote
0answers
436 views

Where is the definition of system_adc_read() in the esp8266 Arduino code?

Where is the definition of uint16 system_adc_read(void) in the esp8266 Arduino code? I can see it being declared in Arduino/tools/sdk/include/user_interface.h, however there seems to be no definition ...
0
votes
1answer
713 views

Read analog signal over the SPI bus using MCP3201 ADC and Arduino Uno

It is possible to use the SPI bus when the Vref of MCP3201 ADC is 2.5V? On the setup i just finished, I used two linear regulators: 5V -> 3.3V to power the MCP602 op-amps and MCP3201 ADC, and another ...
1
vote
4answers
1k views

what is arduino adc reference?

I'm using arduino for the first time and don't really understand what am I suppose to plug to the ADC refernce PIN... or if I even have to use it while plugging analog sensor to the arduino, thanks!
1
vote
2answers
220 views

Lowest voltage applicable on AREF pin on Uno and Mega

I need to measure an Analog signal in the range of 5-30 mV. Naturally, using the internal default 5V reference leads to very poor measurement resolution. I would like to use the capability to use an ...
0
votes
1answer
85 views

External ADC reference when using MATLAB support package for Arduino

I am using the MATLAB support package for Arduino. However, I need to configure the ADC reference to external. MATLAB documentation doesn't really explain how to do this? Is there any way I can use ...
1
vote
1answer
44 views

Using Li-Poly battery to run UNO + Adafruit data logger

I want to power Arduino UNO+Adafruit data logger (https://www.adafruit.com/product/1141) with a 3.7V 2000mAh Li-Poly battery. I am providing an excitation voltage of 3V, through one of the digital ...
1
vote
0answers
63 views

ADC pin shutting off on its own under certain condition

A0 pin not working when full PV system in use I am using the DFRobot Leonardo with Xbee R3. I am using the A0 pin to read a 0-5V voltage from my voltage sensor, which samples and steps down 130VDC ...
0
votes
1answer
51 views

Where to remove an ADC bias?

I'm using several ACS712-based 5A current sensors. They're non-polar and so (I gather) the output is biased to Vcc/2 to allow a swing in either direction. The sensor outputs +/- 185mV/A, plus the bias....
0
votes
1answer
34 views

How do i fill the second byte?

I am using I2C communications to control a AD5694RBRUZ (http://www.analog.com/media/en/technical-documentation/data-sheets/AD5696R_5695R_5694R.pdf) with my Arduino Nano. If i enter two bytes it wil ...
1
vote
2answers
807 views

Arduino protecting analog input with internal voltage reference

Usually a common way to protect an analog input consists on reducing voltage and current in the following way: Current limiting components, as Resistors or inductors and voltage limiting components ...
0
votes
2answers
425 views

How do I calculate sampling rate of external ADC?

I am wondering if someone could explain this to me. I want to calculate sampling rate of external ADC. I am using ADS8320 which has max sampling rate of 100kHz, with Arduino MEGA 2560. SPI divider is ...
2
votes
1answer
219 views

Attiny85 - Method to discard glitched ADC values?

I have a problem i need to solve so i will simply it as much as possible. Basically there is a system with a micro-controller where it reads 2 sensors. These 2 sensors are of variable resistance type,...
4
votes
1answer
149 views

Can I connect a voltage, higher that the 1.1V bandgap voltage, to an ADC pin

Can I (attempt to) measure a voltage that is higher that the ADCs Vref, without damaging my IC? I'm trying to measure the battery voltage using a resistive divider, and using the internal 1.1V ...
-1
votes
1answer
215 views

Start I2C communication at an external event

I'm working on a Arduino Uno and a ADC ADS1115. Devices communicate by I2C where Arduino is the master. I would like to use the ADC to the maximum of his possibility. So i configure the ADC to set a ...
0
votes
3answers
268 views

High Speed Thermocouple Readings

I'm currently attempting to take readings from 10 thermocouples using an Arduino Mega. I've been using MAX31850 1Wire Thermocouple Modules (with the Adafruit breakout) to perform the readings, but ...
2
votes
4answers
1k views

How to speed up Due ADC

I'm doing a project where in I'm using Arduino Due to measure the time difference of arrival of signals to four piezoelectric sensors. The piezo sensors where glued on a board and we want to localize ...
0
votes
1answer
248 views

External ADC reading zero while input is zero

Using ADS1115 (or any other external ADC), how its possible to read zero instead of random floating values while no any signal at the ADC's input pin? The ADS1115 is driven by an op-amp buffer as ...
0
votes
2answers
303 views

Optimizing ext. SPI ADC for speed and verify the speed

So I have a project where I will be using an Arduino Leonardo and an external ADC (AD7980) to run a 16-bit (18bit) conversion and transmit it to the Arduino and then out on USB as fast as possible. ...
0
votes
3answers
461 views

2.4Mhz clock for 3-wire SPI using Arduino Mega 2560

I am trying to develop an Arduino sketch for ADS8320 ADC IC, which is 3-wire SPI. I need a 2.4MHz serial clock for the SPI interface. I tried the code below, but I don't know how to generate clock ...
1
vote
2answers
602 views

Uno - measure the voltage, NOT connecting GND

I'm trying to use an Arduino Uno, to measure the Voltage over a Resistor in a circuit. I guess the usual way would be to connect GND to one side of the Resistor and the AD0 Pin to the other end, and ...
0
votes
2answers
1k views

Transfer 10-bit via Arduino-to-Arduino SPI protocol

The task I need to accomplish is as follows: I have an analog/digital converter that sends out a 10-bit signal. This signal needs to be transferred to an Arduino Uno using the SPI protocol. Because ...
8
votes
2answers
2k views

Why analogue pins affect each other?

I have a sensor and it generates an analogue signal. I am reading all analogue data and sending it to my computer. uint8_t sensors[] = { A0,A1,A2,A3,A4,A5,A6 }; const int len = sizeof(sensors) / ...
11
votes
4answers
3k views

Does ADC conversion to a voltage rely on the actual value of the +5 V pin?

Questions: Does the conversion of the ADC count to voltage depend on the actual voltage of the +5 V pin? If yes, what is the accepted method of getting that voltage from the board? Background/...
1
vote
0answers
287 views

Attiny13 analogread() not working on all pins

I am new here and perhaps you could help me. I am trying to program Attiny13 with the following short sketch which uses ADC (analogread()) function, that is supposed to work like this: reads voltage ...
1
vote
3answers
272 views

Specific noise while using arduino ADC in free running mode

To make an oscilloscope in matlab environment, for data acquisition on arduino side, when inbuilt analogRead() is used, it's working fine, but with very low sampling rate, that aliasing is clearly ...
0
votes
0answers
129 views

Pressure Sensitive Touchpad using Arduino with External ADC

I am using an external ADC with Arduino. I connected 3 pins (let's say a1, a2, a3) of the ADC with 3 external pull-down resistors. I am using three digital pins (d1, d2, d3) from Arduino, setting each ...