Go Down

Topic: Supply for handmade arduino (Read 1 time) previous topic - next topic

CrossRoads

The diode prevents the  reset line from spiking up to a high voltage when the reset switch is used and causing the chip to think its going into high voltage programming mode, and appearing to the user as if it had locked up. This is implemented in later model Arduino's.
See Section 3 of Atmel App note.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

retrolefty


AREF is also connected to AVCC, instead of being independent - with its own 0.1uF cap.
No diode across the reset resistor either.
Bare minimum designs have certainly been drawn up better:


That attached drawing has that old error on Avcc pin and C5.

Lefty

Go Up