AVR is a 8- and 32-bit microcontroller core developed by Atmel. AVR was chosen as microcontroller for the popular Arduino SBCs.
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166 views
What are the odds of a miscalculation in an Arduino?
I am running an experiment using an Arduino that requires several million calculations per second to be performed by an Arduino. I was wondering the odds (if any) that one of these calculations is ...
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0answers
21 views
GLCD t6963 auto write problem
I am trying to send data to a 128x240 display driven by t6963 in autowrite mode by ATMega128 under AVR-GCC.
the code gets stuck when checking DAWRDY bit ( to see if the driver is ready for receiving ...
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1answer
53 views
What to do with ATmega's XTAL pins when using the internal oscillator?
The XTAL pin on the ATmega16a for example can't be reused as I/Os and I really don't need an external crystal. What do I do? I assume pulling them either high or low is better than leaving them ...
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1answer
108 views
Why does the delay between bytes increase when I increase UART baud rate?
Something interesting to note, which I am not fully understanding. My UART is initialized with 9600 baud. I've looked at the TX on the line via logic analyzer, and the bytes I send have minimal delay. ...
5
votes
1answer
158 views
Low-side MOSFET: Current seems limited
I'm trying to use a MOSFET, an N-channel (specifically this one), with a gate controlled by an AVR to power on/off a Raspberry Pi (powered through GPIO), I'm using it on the low side. (Both share the ...
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2answers
184 views
How to measure -50V to +50V using a microcontroller ADC?
How to measure -50V to +50V using a microcontroller ADC?
I would like to scale my signal so that -50V signal voltage equals -5V at the input to the ADC and +50V signal voltage equals +5V at the input ...
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0answers
32 views
STK600 erases ATMEGA2560 on restart
I have been working on my project with a STK600 for months. It has a ATmega2560 on it and I have just found strange problem. When I flash program on controller it works fine and also resets fine, but ...
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1answer
79 views
What's the difference between AT89S52 and AT89C52?
I am working on a fingerprint security project, based on what I've read so far, I decided to go for AT89S52 as my microcontroller, but I got stuck when I decided to simulate my circuit on Proteus 7.8. ...
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1answer
66 views
I2C with only ground common
I'm playing with I2C on an AVR. I need the devices separated, and each device has its own battery. For the I2C I'm not clear if it is OK to have the pull up resistor within the source device, then ...
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1answer
59 views
AVR strange togle LED behaviour
Im following some basic tutorial for AVR
all seems fine but the speed?
the problem is that if I leave the speed of the xtal commented the code works,
but if I place it in 8 mhz or 16 mhz [im using ...
4
votes
2answers
90 views
MCU crystal capacitor selection
I will be using the AT32UC3C2512C, the AVR32768 Application note recommends 22pF capacitors for crystals up to 16MHz...I will be using a 20MHz crystal, should I choose a 22pF or a 15pF loading ...
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1answer
36 views
_delay_ms not working with ATmega 16/32
I had purchased an ATMEGA 16 microcontroller and chaged its fuse bits settings and used internal caliberated RC clock with 1000000.
Changes done in make file and F_CPU. But it do nothing.
Programme ...
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1answer
59 views
Does MSP430 and AVR have internal pull-up on UART's RXD line?
Suppose a device with MSP430 or AVR microcontroller and floating UART lines (e.g. to external connector). Need I add an external pull-up to the RXD line?
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votes
1answer
105 views
PWM Modes: Center Aligned and Left Aligned
I am using the Atmel AT32UC3C2512C and looking into the datasheet there are two kinds of PWM modes: Center Aligned and Left Aligned.
I would like to know when one is supposed to use each one of ...
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votes
5answers
145 views
How to know usb connection is lost
I am working with AT90USB1287 controller with USB communication to PC. I am sending some commands from PC to controller using USB communication to activate some controlled switch. I am able to change ...
