Tagged Questions

-2
votes
0answers
66 views

How to stabilize the value of ADC in PIC microcontroller? [closed]

I have been designing auto range multimeter using PIC microcontroller. Having problem in the auto range switching due to the ADC reading since ADC reading for particular voltage varies by 100 to 150 ...
2
votes
1answer
92 views

ADC of ATmega32

I want to use an ATmega32 ADC in its 4 channel single-ended mode to convert four analog signals into digital (one at a time). I have written the C code but what I cannot figure out is what I should do ...
1
vote
3answers
104 views

Selectable Voltage Divider Optimal Switching Point

I've built a circuit to measure an unknown resistance (over a large range) which is basically the following: simulate this circuit – Schematic created using CircuitLab Range_Select_1 and ...
3
votes
1answer
97 views

How to interpret microcontroller ADC module on datasheet? Datasheet syntax question

I am currently working an Atmel micro controller, the EVK1104S, which has the UC32 Data Sheet. We have actually planted this chip on a custom PCB and are in the process of writing more firmware. ...
3
votes
2answers
122 views

Analog to Digital converter module of MCU - Conceptual question

Please consider the following codes: ...
4
votes
2answers
99 views

Connecting Analog Signals Between Boards

When you have a sensor with an analog output on one board, and an analog-to-digital converter (ADC) on another board, what's the best practice in connecting them together? For example, if you have a ...
3
votes
3answers
130 views

Differential or Single-Ended ADC?

I'm getting to know the Freescale Kinetis L microcontroller. It's ADC has a lot of options, but long story short, it seems like I should be able to get 16-bit resolution in either single ended or ...
-2
votes
1answer
199 views

DSP with ADC DAC SPDIF IO controlled with Microcontroller via USB

I'm looking for a board to process live music (sub-millisecond latency if possible). I'm thinking of a layout like the following: So there are a few DACs and ADCs, S/PDIF inputs and outputs and a ...
2
votes
1answer
178 views

Reading analog input pic18

I'm trying to read an analog input on a PIC18F65J11, and I'm having trouble. I don't think the pin is set up correctly because I'm getting a 0 for the value I read in, and the input is measured to be ...
4
votes
1answer
358 views

How to inteface LDR with microcontroller?

I need to interface LDR with micro controller, While searching some circuit ideas on the internet I came across two different ideas. One was using a voltage divider circuit with another resistor and ...
1
vote
2answers
419 views

Measuring 32V using ADC of Atmega8

I'm trying to measure the battery voltage of 30V using the ADC of an AVR Atmega8, AVCC is connected to 5V. I connected a suitable voltage divider: R1 is 270k, R2 is 10k. The result I get is wrong at ...
0
votes
1answer
69 views

Weird behaviour of the ADC of an AVR

I'm trying to use the internal reference of the ADC of an ATMEGA8. I'm trying to use it in proteus simulator coded in codevision. The Full scale reading from the ADC is always 200. I didn't connect ...
3
votes
2answers
461 views

Converting 0 to 24V analog signal to 0 to 5V for ADC input?

I'm using ATMEGA16U4 microcontroller and want to Convert the 0 to 24V analog signal to 0 to 5V for ADC input. I read this How to read high voltages on microcontroller? How to Convert 0 to 10V ...
4
votes
3answers
188 views

Resistance to Digital converter

I am trying to make a digital ohmmeter on a parallel port interface that can measure resistance with at least 95% accuracy. I have tried a 555 timer monostable assembly which generates a pulse with ...
3
votes
3answers
135 views

clamp low voltage signal

I have an audio sine signal -300mv to +300mv (600mv p-p), and I would like to read it using a microcontroller. I want to get rid of the negative half of the sine signal. How can I clip it? I do not ...
7
votes
2answers
367 views

Selecting bias resistor for thermistor

Rt is thermistor. Rb is bias resistor, which value I need to calculate. The temperature that I'm interested in is giving ...
1
vote
3answers
220 views

Can we give a bipolar signal to ADC of atmega88?

Can we send a bipolar signal to ADC of atmega. We know that an analogue signal has a positive value as well negative value. So ADC can take a negative value or it just take positive value of a bipolar ...
1
vote
2answers
295 views

Analog to digital conversion

I am using an Atmega32-A microcontroller and an AD7798 external ADC. I am able to set the ADC registers and read back ADC values. I have written the following code: ...
3
votes
1answer
159 views

How to use an audio codec as an ADC?

I would like to add ADC functionality to a TI C6748 dev board. I need 16bit precision, but relatively low sample rate(~5K). Not finding any suitable daughter ADC card, I am considering the ...
3
votes
1answer
178 views

How to measure -15V to 0V using a microcontroller ADC?

How can I measure -15V using the ADC of an AVR microcontroller? I would like to scale my signal so that -15V signal voltage equals 0V at the input to the ADC and 0V signal voltage equals 5V at the ...
7
votes
6answers
2k views

How to read high voltages on microcontroller?

I want to read high voltages, like ~50V, using a microcontroller. I plan to put this as an input into the microcontroller's A/D line. But of course, you shouldn't have voltage that high on the input ...
1
vote
1answer
242 views

Creating the proper Vref for a thermistor

I have a 10kΩ @ 25°C NTC thermistor for temperature measurement. Problem is, I only have 3.3 V on the board and the ADC inside my micro-controller has a Vref of 1.6 V. I tried to make a ...
4
votes
1answer
173 views

battery voltage with microcontroller [duplicate]

Possible Duplicate: Arduino has an input value in disconnected pin I wish to measure the voltage of a 1.5V battery using a microcontroller (supply voltage of 3V). I thought of connecting ...
3
votes
2answers
546 views

Easiest way to go from analog input to PWM output?

Project background: I'm building a plasma speaker. There are several examples online using a TL494 power supply IC and feeding audio into its feedback pin to get sound out. A sample schematic: ...
0
votes
1answer
546 views

How to configure the analog port in PIC18F?

How to configure the analog port of [PIC18F452][1] to read analog values? they need to change their status while running the program..
-2
votes
1answer
147 views

Help finding appropriate AVR device

I am working on a student project and need to find AVR microcontroller that will suit all project requirements. Here's a simple list: serial communication (UART), at least two ADC channels, PDIP ...
1
vote
1answer
205 views

Ripple factor detection and measurement

How to measure ripple factor automatically for a pulsating dc output(0-300 v)?
2
votes
3answers
931 views

Analog to Digital Converter and Negative Voltages

I'm using the ADC on an ATtiny24 to record a AC signal. The ADC has a range from 0-3.3V. I'm using a precision rectifier to get rid of the negative portion of the signal. I've attached a picture of ...
2
votes
3answers
706 views

Implement MicroController Power Switch and re-use the button for other features

This is similar to other questions, but I feel it is different because of the reuse of the "power" button. I want a "latching" Momentary Power button. Behavior: User Pushes momentary button, ...
2
votes
2answers
669 views

Microcontroller with ADC and capable of SPI communication

I am designing a system where Analog Signal ---> (ADC- Digital Data )---> UWB chip mostly WSR601 or AL6301/AL5100 Chipset Note (1): UWB is an abbrieviation for Ultra Wide Band wireless ...
0
votes
1answer
268 views

Communication between modules over USB using a uC

I have a module (say A) which sends data serially to me at 5 Mbps. I want to transfer this data to another module (say B). For B, I have a few choices for links: USB, UART, PCI/E, etc. I am not sure ...
1
vote
2answers
2k views

ADC input protection?

I need to sample an analog voltage from a sensor (0-12v) in an environment where large voltage spikes may be induced in the transmission line, what's the best (simple and cheap) method of protecting ...
1
vote
2answers
1k views

ADC sampling rate to MCU clock speed relationship

How can I determine the clock speed requirements of a mCU to manage a given ADC input? This application is very simple - I just want to take an SPI stream from an ADC into a mCU and spit it out the ...
-4
votes
1answer
144 views

What does it mean 0.1“ w.c. to 20” w.c.? [closed]

It is in a Dwyer series 607 datasheet ( Low Range Differential Pressure Transmitter).
6
votes
6answers
2k views

How do I sample a -2 V to +2 V analog signal with a PIC microcontroller?

I am using a PIC micro with a 10bit ADC to take readings from an analog signal with a frequency less than 300 hz. However that analog signal is in the range of -2 V and +2 V. How can I condition the ...
4
votes
3answers
650 views

Increasing ADC resolution by supersampling on a successive approximation ADC

Is it possible to increase the resolution of an ADC by supersampling on a PIC24F ADC, which has 10 bits of resolution and is implemented using a successive approximation engine? Speed is not critical ...
7
votes
3answers
915 views

Auto-Ranging Meter Design

I'm designing an auto-ranging voltmeter using the on-board ADC of my micro for A to D and a digital potentiometer as a programmable resistive divider to control the range. My concern is the ...
8
votes
5answers
2k views

ADC input impedance on MCUs

What is the input impedance of a typical MCU ADC? In this case I'm working with a PIC24FJ64GA004. I don't need high speed sampling - a maximum of 100 samples per second. I wish to connect a resistive ...
22
votes
5answers
6k views

How do I measure a negative voltage with a ADC?

I am working with a PIC micro-controller with inbuilt 10bit ADC and want to measure a voltage in the range of -1 to -3Volts. I thought of using an op-amp in the inverting mode to make voltage positive ...
5
votes
2answers
619 views

What MCU, need hi res ADCs?

I'm trying to find a powerful MCU that has multiple analogue to digital converters. I want around a 14 bit resolution to do some serious audio sampling. Any suggestions or comments would be great, ...