ATB Manual rev:1.04

J6 and J7 jumpers serves to connect Rx (PD0) and Tx (PD1) lines of microcontroller directly to the USB/RS232 adapter. You should remember that if you want to use PD0 and PD1 pins of a processor to other purposes you should open J7 and J6 jumpers. Thanks to it you can use, absolutely independently from the USB/RS232 adapter.

SDA jumpers and SCL serves to convenient I2C bus disconnection, which is also by default connected to the PC0 and PC1 pins in microcontrollers ATmega32 type. The jumpers let to freely use the two independent integrated circuits that are standard equipment of the kit, namely: RTC chip in form of PCF8583 (real-time clock) and also a memory EEPROM 24C04 type.

Because the pins: PB5 (MOSI) , PB6 (MISO) and PB7 (SCK) are used for programming with ISP use, so you shouldn’t connect directly to them integrated circuits that serves as outputs I/O type because it can disturb the programming process. The most common example of troubles, among beginners occurs when to a B port of a microcontroller you will connect e.g. data lines of LCD displayer.

The microcontroller clocking options – that is one of the biggest advantages of all our start-up kits. The kits have all possible sources of external clocking and we can make a simple choice between them using a simple combination of three jumpers JK1, JK2 and JK3. An user hat to his disposal:

1. External crystal oscillator (by default 11,0592MHz)
2. External RC oscillator
3. External TTL generator

An extremely important feature of our kits is the fact that a user has full opportunity to exchange the crystal oscillators. A special socket built in ensures trouble-free performing many exercises during programming learning and also own project prototyping.

All the kits from ATB serie can be powered in three different ways.

Currently our kits are equipped with specialized power converters based on an integrated circuit A8398. To select power supply source you should set PWR SEL jumper properly. In USB position the power supply is taken from USB port of a PC and in EXT position (external) from external power supplier through the converter. A huge advantage of our converters is they do not emit large amounts of heat as it takes place using line stabilizers 7805. In addition our converters are not mounted permanently (you can take them out and use outside e.g. on a breadboard, when we use USB power supply) and also they are equipped with simple logical system that lets for control of the converter to turn it on and off. Details are described here LINK and for selecting power turning off option we can use S_on pin on which there is a jumper closed by default because it allows for constant work of the converter after power is turned on. If a user would like to use an option of software power supply turning off from the microcontroller level then he should take off the jumper from the S_on pin and connect the pin directly to the microcontroller (any port). You should remember here that in the software, right after program start you should immediately set high state on this pin. But if we want to turn off the power of the entire kit using software then it is enough to set a LOW state on the specified pin what will cause immediate turning the converter off. In the converter there is also a micro-switcher. It has a very practical functionality. After power supply connection from an external power supplier the converter is set by default in this way that it doesn’t start so the entire kit is switched off. When we are ready to work we can just click on a micro-button and the kit will be powered. Thanks to the converter we also have a possibility to chose power voltage: +3,3V and +5V (+5V by default). On the power supply input, before the converter there is a diode that protect against accidental reversed connection of power supplier pole.