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ZBasic Language Reference 189 ZX Microcontroller Family Appendix I - ZX-32n and ZX-32l Hardware Reference The ZX-32n and ZX-32l devices utilize the 32-pin TQFP package version of the Atmel AVR ATmega328P microcontroller that has been programmed with a special ZX control program. In order to use the ZX-32n 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-32 Specifications The electrical specifications of the ZX-32 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-32 Required External Components The circuits described below represent the minimum external circuitry required to operate the ZX-32. Depending on your application, you may need additional circuitry to take advantage of the capabilities of the ZX-32 series device. In contrast to some other ZX devices, the ZX-32 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-32 needs a regulated voltage source capable of providing at least 200mA of current. The ZX-32n 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-32 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 18 would be connected directly to the power source (same as pins 4 and 6) and pin 20 can be left open. Although not shown on this diagram, the ground pins of the ZX-32 (pins 3, 5 and 21) must be connected to the common ground of the system.