Various Circuits

This "SimpleMouse" Smartcardprogrammer can be used to read and write most of all async - Smartcards (Processorcards), including the new "Hornet and +1" DPSC΄s in update and reprogramming mode. It is jumper-selectable in either Smartmouse or Phoenix Mode (Reset active hi or low) and Jumper selectable for 3.57 and 6 MHz.

Most of the ideas in this chapter can be found on the pages of this website, but just in case you want to go over the capabilities of the '508A, we have brought them together. Quite often when you are programming, the first thing you will run out of is output lines. Many projects need lots of drive lines and if you need more than about 8, you should go to another micro-controller. Don't expect an 8-pin chip to perform the impossible.

Since I implemented a D type flip flop using the PIC Logic Elements I thought I might go the other way and implement an entire D type flip flop in a single PIC. This uses the edge triggered and port change status interrupts and was an opportunity to have a play with interrupts on the PIC. As written this code will cause a PIC to function as a negative edge triggered D type flip flop with active low Set and Reset inputs.

This is a successor of the PIC16C71 4-digit LED f-counter & V-meter. Some hard to find parts used in the previous version, which are out of production for some time, has been omitted. A rather early PIC16C71 has also been replaced by 28-pin device PIC16F876. The later is capable of driving 4 digit LED display in multiplexed mode while measuring frequency, power supply voltage as well as handle two analog inputs to display SWR/PWR signal strength in a bargraph manner.

The project consists of 35 LEDs arranged as a 5x7 matrix. This may not seem very impressive but you can display all sorts of effects and treat it like a "window on a large video screen." The project comes with a series of test programs to test the operation of the screen and also the surrounding components. Then we come to the experiments. They start with a simple routine to illuminate a single LED and progress to flashing a LED, running a set of LEDs up and down the screen, and then a variety of animations.

Figure 1 shows the complete hardware schematic of the 68k SBC. U1 is 68-pin PLCC 68HC000 CMOS cpu. Y1 is 8MHz oscillator module. The reset signal is generated by power on reset chip, MCP120. The 16-bit data bus, D0-D15 are tied to memory chips directly. D0-D7 are tied to odd byte and D8-D15 to even byte. As can be seen in the schematic, I used 512kB FLASH, 29C040. It needs A1-A19 address lines. But the prototype used only 128kB FLASH, 29C010. It needs only A1-A17. Since the 29C0101 does not use pin 30 and 1, so we can put it to the board without the need of modification.

The circuit in Figure 1 uses a Microchip 8-pin µC (PIC12C671) as a voltage-controlled oscillator (VCO). Because the PIC12C671 has an internal 4-MHz oscillator, four-channel 8-bit A/D converters, and built-in power-reset circuitry, you need no external components to configure the VCO. The µC reads two analog inputs through AN0 and AN1. The reference voltage for the A/D conversion is the µC's power supply VDD. The converted 8-bit data determines the duration of output high and output low.

I decided to rename C52EVB to be 8051SBC. Since the cpu can be any 8051 compatible chips with 40-pin DIP package. The old day chips, say 8031, 8751, 8032 or the new chips, 89C51, 89C52, 89C51RD2 can be used without any problem. Some may think that your old chips were useless, now you can use it for many projects. The monitor program of new 8051SBC was placed at external 32kB EPROM. With this space, you can customize your own monitor code or even add the application program and have the DIP switch to boot it when power up.

I decided to rename C52EVB to be 8051SBC. Since the cpu can be any 8051 compatible chips with 40-pin DIP package. The old day chips, say 8031, 8751, 8032 or the new chips, 89C51, 89C52, 89C51RD2 can be used without any problem. Some may think that your old chips were useless, now you can use it for many projects. The monitor program of new 8051SBC was placed at external 32kB EPROM. With this space, you can customize your own monitor code or even add the application program and have the DIP switch to boot it when power up.

This single sided proto board provides an economical solution for developing and testing the projects around Atmel 20 pin series u-controllers (89Cx051 & AVR)