54 Threads found on edaboard.com: Avr Transistor
May be this can
Hobby Circuits and Small Projects Problems :: 11.05.2012 10:41 :: DeepOne :: Replies: 5 :: Views: 1646
Hi Jack// ani,
As artem suggests you don't need the num array. It's enough to shift left the temp variable. Setting DDRB register it's a must if you drive the LED directly. If you drive them through a driver (say a npn transistor) you don't have to bother since the internal MOS pull-up resistor will source the current to bias your transistor (10
Microcontrollers :: 17.03.2005 23:36 :: silvio :: Replies: 14 :: Views: 1466
Microcontrollers :: 30.08.2006 08:40 :: zhonghua_li :: Replies: 19 :: Views: 6872
how can i acess a steper motor using avr??
Microcontrollers :: 30.11.2006 12:29 :: mr_byte31 :: Replies: 5 :: Views: 1541
I had spare CPLD ISR from Cypress,It looks like ISP programmer for avr and AT89SX.
contain HC244 and transistor with C and r and connector for parport.
Did someone knew had to change it from ISRCPLD became ISP for avr or
Microcontrollers :: 07.08.2007 04:04 :: huys cobb :: Replies: 0 :: Views: 714
i just want to check the port state after programming the atmega8 avr may be one led on every pin with transistor driver ckt.please also recommend me the crystal value for atmega8
Microcontrollers :: 03.09.2007 05:19 :: zohaib :: Replies: 4 :: Views: 802
I try to connecting 2 board.
the 1st board contain avr, it's output is ttl signal clock.
the 2nd board, is the receiver of ttl signal, it use 74hc14n chip.
at the input stage of 74hc14n, i put 10k pull up, followed by 10k resistor to input pin of 74hc14n.
it don't work.
is it because I use different power source & ground on each boar
Hobby Circuits and Small Projects Problems :: 07.11.2008 03:42 :: xinz :: Replies: 4 :: Views: 1490
I am doing my first avr exp using a temp sensor LM35 to blink blue green or red led according to the temp of the room.
• Connected the leds to PORT B of atmega8L uC and temp sensor to ADC 3 input.
• Using internal oscillator 1MHz as clk, internal reference voltage of 2.56 as reference voltage in FREE RUNING MODE.
Microcontrollers :: 03.07.2009 12:05 :: welkyb :: Replies: 1 :: Views: 1485
I need to know the advantages of using Max232 (if any) against simple resistor-transistor level converter for serial port avr programmer.
Is max232 able to provide some better level of protection to serial port and avr Mcu compared to to resistor-transistor level converter?
Thank you very much
Microcontrollers :: 30.01.2011 00:37 :: liteon :: Replies: 16 :: Views: 2116
Hi everybody i am new to rf module interfacing (using avr) and am not being able to implement it,Can anyone please suggest some solutions or guide me on how to make it work.
avr tx to transmitter module(433mhz)
receiver module to rx pin
i dont know what changes to make and really need a lot of help here, been stuck for days...
Microcontrollers :: 15.06.2011 00:17 :: rishiisme :: Replies: 10 :: Views: 2259
Recently I designed a High voltage circuit based on avr microcontroller. I need your opinion or any suggestion or improvements I could add to the presented project.
Microcontroller is responisible for giving appropriate PWM pulse (of known frequency) to the MOSFET transistor. Pwm signal from the uC goes to the op
Analog IC Design and Layout :: 13.10.2011 11:57 :: ifryd :: Replies: 1 :: Views: 1131
It is a project of a testing plate for avr. The whole system consists of two sub-systems: uC Programmer and main testing plate.
Construction of main testing plate:
slot for connecting various adapters
Show DIY :: 26.10.2011 15:14 :: Vermes :: Replies: 0 :: Views: 521
I can't explain why the transistor turns on when the input is set to low.
The input current for the transistor should be 1/10 to 1/20 of the collector current to have a low voltage drop on the transistor (saturation) so a 470 ohm to 1K should be fine, the avr output can handle it.
---------- Post added at 12:50 ------
Electronic Elementary Questions :: 19.01.2012 05:50 :: alexan_e :: Replies: 14 :: Views: 2159
I have a transistor that blew in a stereo amplifier. It is a denon avr 2500 causing the protection mode to engage. I hear this is pretty common. I found the faulty transistor and have no idea on two things 1) how to identify it and 2) how to buy it once i have identified it.
Here is a picture that is close to the one that blew.
Hobby Circuits and Small Projects Problems :: 31.01.2013 19:42 :: sammykid :: Replies: 2 :: Views: 417
Can anyone tell me the avr controller which has capability to invert its uart o/p( uart RX & tx should be ideally low rather than high)
i dont want to use transistor logic for that ,since i want to compact my design.
i think through the software i can only invert data & not start bit & stop bit
Microcontrollers :: 30.04.2013 11:41 :: vishu489 :: Replies: 3 :: Views: 351
Of course, you can do that like standalone circuit with or without mcu. Use any of above 3-pin ICs and connect them like on schematic and pass to mcu input pin or to base of some transistor.
Example with mcu (12c508 or 12c509) link:
You can do this with any mcu (PIC,avr,...)
Example with standar
PC Programming and Interfacing :: 13.01.2003 13:27 :: meax98 :: Replies: 8 :: Views: 3758
What actually need? Hardware/Software
For Software simply use
For Hardware put a transistor between motor and PWM port of avr. :wink:
Robotics and Automatics Forum :: 30.09.2003 06:35 :: sadat007 :: Replies: 2 :: Views: 1877
Did you mean without any hardware , just direct link from the serial port or parallel port to the mcu !!!!!
Of course NO you can't
becuse in the case of the PIC or avr you need at least RS232 <--> TTL converter (two transistor min. with few resistors )
There are bootloader that receive a hex code from serial port and update the
Microcontrollers :: 29.07.2004 22:17 :: SphinX :: Replies: 3 :: Views: 944
I created a long range IR beam detector for a project you might be able to get some ideas from there
Hobby Circuits and Small Projects Problems :: 02.03.2005 07:46 :: jshroff :: Replies: 15 :: Views: 20404
Yes it works with 6MHz resonator, but I think 12MHz is too much, but you can try it if you want..
What kind of compiler do you have? CodeVision avr is really good choice o programming practising. And if you want, I may give you some examble codes..
Microcontrollers :: 29.04.2006 05:20 :: Tugge :: Replies: 5 :: Views: 810
Check this site:
It's Polish. However it's excellant and supports 89Sxx and avr.
Microcontrollers :: 14.10.2006 16:38 :: Khurram Shahzad :: Replies: 6 :: Views: 2275
use L298 or L297+L298 combination
you can use L293D also.See how i had done for avr, use the same logic and hardware for your PIC
Microcontrollers :: 27.02.2007 00:45 :: yogi :: Replies: 3 :: Views: 2032
You can also simplify it further, by connecting line 3 (--->>3) directly to RESET and eliminate the BC547 transistor(Q2) and R1&R2.
The transistor is just an invertor, and you need configure PonyProg to invert RESET signal.
I am using this simplified - only resistors and diodes - circuit since 2004, but only on avr microcontrollers.
Microcontrollers :: 11.06.2007 16:26 :: Eugen_E :: Replies: 3 :: Views: 1002
Now, I having a problem with the protocol RS232 to RS485. I posted my schematic and could any body help me check it?
follow this circuit, when I brake pin 9 (MAX232) and connect to VCC or GND, transmit and receive was OK. But I keep intact this pin's connect, I couldn't transmit or receive...:?:
Please help me!
My project was design
PC Programming and Interfacing :: 06.08.2007 06:29 :: member_tdh :: Replies: 3 :: Views: 7026
There is a chip L296/L297.This is used for driving stepper motors.Just download the datasheets and it will give a very easy way to interface your avr micro to a stepper motor.
Microcontrollers :: 12.08.2007 11:39 :: yousafzai :: Replies: 10 :: Views: 2395
I guess it's for a classic (wired) telephone. In this case you need a DTMF receiver (MT8870 or other), a microcontroller (avr/PIC/8051...), a transistor and a relay.
The relay contacts should be connected in series with the telephone.
When the number is dialed, the uC reads the DTMF receiver and if the number it's not accepted, it will activ
Hobby Circuits and Small Projects Problems :: 08.05.2008 12:52 :: Eugen_E :: Replies: 4 :: Views: 1462
I hope that you will be having the remote for the device you want to control.
In a fast micro like avr, write a cap-com type of program using dual Interrupt and find out the timing. Using this you can determin the type of code.
Next task is to make a 38KHz IR transmitter.
This would be easy if you have a PWM on the Micro you are using.
Microcontrollers :: 10.07.2008 12:40 :: boseji :: Replies: 1 :: Views: 932
I need to use SPI bus on a big Printed Circuit Board (width: 70 cm). Near master microcontroller, there is a SPI DataFlash chip which must be accessed by full speed of avr's SCK line (8 MHz).
Now I routing PCB and I am worry about refection on bus when master accessing DataFlash chip (about 50 cm float wire).
Is it reasonable to discon
Microcontrollers :: 01.08.2008 16:28 :: rezaxyz :: Replies: 3 :: Views: 5996
Hey i made a 4 digit 7 segment based display using avr working fine. I have a reservation in mind regarding power consumption of avr. Currently i m using common cathode display (multiplexed by NPN transistor) which turns on segment when avr's Port output is high. So it must b consuming more from microcontroller. On contrary (...)
Microcontrollers :: 21.02.2009 23:31 :: waqas_here :: Replies: 2 :: Views: 2726
so i have made it great tool here is my picture with modified hardware also for latest firmware and source code go here
avr-transistortester - Download
Show DIY :: 26.01.2011 04:34 :: Fragrance :: Replies: 1 :: Views: 3891
I am planning on voltage-regulating the speed of a DC-motor using a "R/2R" ladder (DAC).
A picture of my schematics is posted below. Intending to use 4 bits resolution, wich I get from atmega32 avr. Each bit is amplified trough a transistor, because I cannot drain much current from the microcon
Analog Circuit Design :: 19.12.2009 11:46 :: cough-e :: Replies: 2 :: Views: 939
i want to implement a 555 based flasher using a relay..
i have two digital signals a Enable signal (thats active low)and a Freq_selection signal that selects the frequency of flashing or we can call it a duty cycle selection...
i am not concerned with the exact freq. rather i want the flasher to look as flashing fast at logic 1
Analog Circuit Design :: 07.08.2010 03:41 :: sherazi :: Replies: 1 :: Views: 452
Is there a microcontroller that outputs low when it is reseted ?
the atmel 89c51 outputs high on all ports upon reset and that will make some trouble with my circuit
avr, PIC, etc..
Microcontrollers :: 05.10.2010 12:59 :: nandhu015 :: Replies: 9 :: Views: 630
Are you sure that your avr pins are set up as outputs?
I don't see a way that this can happen unless you pull too much current from the avr and you don't do that, unless you have damaged any of your pins before.
You can try with 3 leds connected to the 3 outputs of the avr, each with a resistor about 300 ohm, anode to the vcc supply and (...)
Electronic Elementary Questions :: 17.12.2010 10:10 :: alexan_e :: Replies: 5 :: Views: 795
Depending on the motor type there are different coils that have to be driven with a specific sequence,
this sequence change the rotation direction.
You can find many articles on that,for example
Controlling Stepper Motors with a PIC Microcontroller
PLD, SPLD, GAL, CPLD, FPGA Design :: 04.03.2011 08:26 :: alexan_e :: Replies: 8 :: Views: 2153
I don't see any problem with your connection so it must be your program
or you have done something previously to damage either the avr pin or the transistor.
Disconnect the base resistor from the avr, the 10K pull down will hold the transistor in off state,
then connect the !K input resistor to 12v, it should turn on. (...)
Analog Circuit Design :: 01.04.2011 14:14 :: alexan_e :: Replies: 3 :: Views: 5593
I think you mean a unipolar motor, it has 5 wires, 1 is the common and the other four are the 4 coil sides.
It is much easier to drive than a bipolar, you don't need an H-bridge, connect the common to the positive supply and use four low side switches (uln2003, transistor, mosfet) to enable each of the coils
You can drive it with an ULN2003 or
Microcontrollers :: 30.05.2011 10:15 :: alexan_e :: Replies: 51 :: Views: 1718
check out my code for displaying no. on 7 seg: All About VHDL Codes, PCB Designing and avr: bcd to seven seg decoder in vhdl(synthesizable)
a simple 0 to 9999 counter on 7 seg : All About VHDL Codes, PCB
PLD, SPLD, GAL, CPLD, FPGA Design :: 31.05.2011 13:52 :: jimmy_tag :: Replies: 13 :: Views: 2348
As you saw on other's reply, only 8 transistors are enough.
You can't be sure of that, you assume that each mcu pin can provide about 10mA and that the mcu can provide a total of 80mA (8 pins combined) when number 8 and the dot is turned on.
Not all MCU can provide that current, an avr or a PIC can but many others can'
Electronic Elementary Questions :: 17.06.2011 14:17 :: alexan_e :: Replies: 5 :: Views: 1150
The following simple electronic system acts as JTAG for Atmega microcontrollers. It uses RS232 port. Because this port is rare in computers, another version of the project using USB was
Show DIY :: 17.11.2011 16:41 :: Vermes :: Replies: 0 :: Views: 781
LED matrix with 2 modules 8*24 connected together, had mounted column drivers on 74HC595, and a place for mounting Atmega8 processor or vertical compatible decoder for lines and power transistor on the bottom.
Show DIY :: 20.11.2011 15:02 :: Vermes :: Replies: 0 :: Views: 1797
>> TRW-24G communication with avr microcontroller
RF, Microwave, Antennas and Optics :: 01.12.2011 10:05 :: ALERTLINKS :: Replies: 28 :: Views: 1412
i m using avr ATmega32 microcontroller
---------- Post added at 06:22 ---------- Previous post was at 06:20 ----------
i m using start,stop,auto/manual,time/up,time/down switch.
Microcontrollers :: 22.12.2011 00:22 :: vairamathi :: Replies: 8 :: Views: 504
Hello. I am using RAM Electronics : ATMEL avr ISP Programmer "avr avrISP V2.0 STK500 USB ISP" - 160.00L.E. to program an at89s52. I am totally new at this. So I wanted to figure out what should I connect to the at89s52 to program it?resistances?vcc? do I use
Microcontrollers :: 27.12.2011 06:25 :: kabaza :: Replies: 7 :: Views: 887
Every Device is made of semiconductors. To perform some specific function, we can achieve that specified task by connecting lot of transistor with proper configurations. (e.g. Building gates from transistors). For very complex applications its not possible to built directly from transistors. To achieve this specified task, we built millions (...)
Electronic Elementary Questions :: 02.03.2012 01:26 :: SughiRam P. :: Replies: 2 :: Views: 630
10mA a power led?
A 10mA LED can be connected directly to the output of the avr (5v) using a resistor to set the current , there is no need for a separate supply.
Professional Hardware and Electronics Design :: 08.04.2012 07:44 :: alexan_e :: Replies: 14 :: Views: 847
I think there is a problem in relay or relay driving transistor, which is used for avr (automatic voltage regulator) in an UPS.
Power Electronics :: 12.05.2012 14:29 :: MAXPAYNE :: Replies: 20 :: Views: 1347
The ULN2003 should be enough to drive the led. The relay is not needed unless the led is high power.
See some examples to use the ULN2003 to drive a led or a relay.
Hobby Circuits and Small Projects Problems :: 06.11.2012 10:57 :: albert22 :: Replies: 8 :: Views: 5814
I'm trying work with the output of a Symtrik RFT-60 WWVB module ( ). From this datasheet, it's an inverted serial output.
Out of pure hobbyist pride, I tried a MAX232 just out of pure thought that even though the input on MAX232 is TTL CMOS 0-5+ (which is surely was exceeding), I thought th
Hobby Circuits and Small Projects Problems :: 01.12.2012 09:35 :: wisehippy :: Replies: 1 :: Views: 695
Hi, I am trying to make an inductive charger add-on for a 3.7 500mAh li-po battery.
I have two flat circular coils each of inductance 14.6uH.
I programmed an avr to make square wave of different freq and driven one coil with a power mosfet (at 10v) and I could obtain some voltage at the other coil. (rectified and connected to an LED). It is work
Electromagnetic Design and Simulation :: 17.12.2012 16:02 :: vinodstanur :: Replies: 0 :: Views: 232