Page 207 of 229 Start Back Next End ZBasic Language Reference 197 ZBasic Microcontrollers Appendix I - ZX-328n and ZX-328l Hardware Reference The ZX-328n and ZX-328l devices utilize the 28-pin DIP package version of the Atmel AVR ATmega328P microcontroller that has been programmed with a special ZX control program. In order to use the ZX- 328n or ZX-32l (hereafter, collectively referred to as simply ZX-328) you must supply several additional components as described below. In each of the diagrams presented below, only a portion of the ZX pins is shown. Those that are not germane to the circuit being discussed are omitted for clarity. I.1 ZX-328 Series Specifications The electrical specifications of the ZX-328 are exactly those of the ATmega328P. Rather than reproducing them here the reader is directed to the datasheet published by Atmel. It can be obtained from the Atmel website |http://www.atmel.com or from the ZBasic website |http://www.zbasic.net. I.2 ZX-328 Series Required External Components The circuits described below represent the minimum external circuitry required to operate the ZX-328. Depending on your application, you may need additional circuitry to take advantage of the capabilities of the ZX-328 series device. In contrast to some other ZX devices, the ZX-328 devices do not require an external EEPROM for program storage. Rather, the compiled user program is stored in the ZX’s internal Flash memory. The maximum user program size is 30K. Power Source The ZX-328 needs a regulated voltage source capable of providing at least 200mA of current. The ZX- 328n will operate reliably with a supply voltage between 4.5 volts and 5.5 volts while the ZX-32l supply voltage can be as low as 2.75 volts. A recommended circuit is shown below. A suitable heatsink will probably be required in most cases to keep the regulator IC below its maximum operating temperature. Consult the regulator datasheet for more information. ZX-328 Power Source If you do not plan to use the Analog-to-Digital converter channels you can eliminate the inductor and the two capacitors on the right side of the diagram. In this case, pin 20 would be connected directly to the power source (same as pin 7) and pin 21 can be left open. Although not shown on this diagram, the ground pins of the ZX-328 (pins 8 and 22) must be connected to the common ground of the system.