F/F Circuit

[Frank Buss]

The professor wants a small box (3"X5")

A 2D box in a 3D world could be difficult. I have to ask my distributor, if
they have some 2D parts.

Next semester we will go further with this but for now, that's all I can
say. Still want to help?

Do you want that we serve up the homework on a plate to you? Which one of
the many suggested solutions doesn't help you?

I would do it with a microcontroller, because there are ones with
integrated power-on-reset and oscillator, like the MSP430F2111 for $2,25,
so you have to write just about 5 lines of assember code to solve this
task. The datasheet says the integrated flash has a life time of 100,000
erase/program cycles, so this should be fine, unless your professor wants
to switch it more often

For the voltage regulator you could use something like the LP2981 for $0.80
from Digikey for 3.3V output voltage, which works then for input voltages
up to 16V and down to 3.5V. All parts would fit in matchbox.

 

[Arlet Ottens]

A 2D box in a 3D world could be difficult. I have to ask my distributor, if
they have some 2D parts.


Do you want that we serve up the homework on a plate to you? Which one of
the many suggested solutions doesn't help you?

I would do it with a microcontroller, because there are ones with
integrated power-on-reset and oscillator, like the MSP430F2111 for $2,25,
so you have to write just about 5 lines of assember code to solve this
task. The datasheet says the integrated flash has a life time of 100,000
erase/program cycles, so this should be fine, unless your professor wants
to switch it more often

Or the PIC12F629

http://ww1.microchip.com/downloads/en/DeviceDoc/41190E.pdf

Only $1.75 a piece at Digi-Key, and has 1,000,000 EEPROM erase/program
cycles. Comes in 8 pin DIP package, so it's easy to solder for
beginners. A built-in status register tells you the reason for the
reset, so you can see if it was just powered on. It also has a wide
2V-5.5V operating voltage and high current I/O pins.

 

[Frank Buss]

Or the PIC12F629

http://ww1.microchip.com/downloads/en/DeviceDoc/41190E.pdf

Only $1.75 a piece at Digi-Key, and has 1,000,000 EEPROM erase/program
cycles.

Looks nice.

Looking at the datasheet, there is a patent cited:

http://www.google.com/patents?id=soIZAAAAEBAJ&dq=5,847,450

They are kidding, right? They can't patent the "invention" that a
microcontroller with n bits data bus has n pins, can they?

 

[JosephKK]

Frank Buss [email protected] posted to sci.electronics.design:

Looks nice.

Looking at the datasheet, there is a patent cited:

http://www.google.com/patents?id=soIZAAAAEBAJ&dq=5,847,450

They are kidding, right? They can't patent the "invention" that a
microcontroller with n bits data bus has n pins, can they?

No, just some other tiny aspect of the device.