Let's Make Robots!

LCD and AVR kit

Hello,

I am doing my own AVR kit. I connected LCD 8x2 on port A and B (RS - PA1; R/W - PB4; E - PA0; DB4-7 - PB0-3) . When LCD is not in the circuit nothing work like power supply is off. When LCD is in the circuit everything run. Connect and disconnect LCD is one of the important part of this kit.

 

L293D 5V in - 3V out

Hi, I have a problem with L293D. On Vcc2 is 5V, but on JP1, JP2 is only 3V.

L293D 5V in - 3V out

Hi, I have a problem with L293D. On Vcc2 is 5V, but on JP1, JP2 is only 3V.

Capacitors

Hi, can I use in circuit however big capacitor or do you know some article about using capacitors? Thank you.

log. voltage

Hi, in my new robot I am using ATmega644, but I need hepl with log. votage. In AVR Studio I set PB7 out and set log 1, but when I measure voltage between PB7 and GND, multimeter shows 0.8 - 1.1 V. Had anybody same problem? But it is not only PB7.  The 0.8 - 1.1 V are on all ports. When I put atmega in to breadboard everything is OK.

I have connected LCD to PORTB and PB7 is controlled backlight. When PB7=1 then backlight on but when I measure voltage on PB7, multimerer shows 0.8 Volts.

 

Atmega - Programming Flash .. FAILED!

Hi, when I want put program in to Atmega644 it shows: Erasing device .. FAILED! , but when i click on "Read Signature" everything is OK. I am using programmer compatible with STK500 and AVR studio. Help please.

Bluetooth AT commands

Hi I bought bluetooth module from ebay. I connected to the atmega and comunicate with my laptop. It works great. I set (in atmega) communication 9600 Bd, but hyperTerminal (auto-detect) shows 2400 Bd. I tried lots of tutorial how to change baud rate (or name, key, ...) using AT commands, but Hyperterminal does not work and the other also. They connected to bluetooth, but when I try wrote something it does not shows in terminal (keboard do not work :D in terminals ). Any idea how comunicate with bluetooth using AT commands? Sorry for my English :) .

3x Ultrasonic sensor

Hi I have problem with reading value from 3 ultrasonic sensor. I use Atmega644P and trig is conected to PD5-PD7, but echo from all sensors conected to PD2. I tried read value and wrote to LCD. When I disconnected all sensors the some values are on LCD, but when I connected all sensors and click to reset the LCD is clear.