16 MHz => 8 MHz for EMUPS4

Talk about anything concerning the source code.
Post Reply
mstrVLT
Posts: 8
Joined: Thu Jan 28, 2016 11:30 pm

16 MHz => 8 MHz for EMUPS4

Post by mstrVLT »

I need set F_CPU = 8000000 (8 MHz) for EMUPS4
Will it work? What do you think?
Maybe need change USART_BAUDRATE 500000 to ...
User avatar
Matlo
Posts: 5768
Joined: Wed Jul 06, 2011 7:01 am
Location: France
Contact:

Re: 16 MHz => 8 MHz for EMUPS4

Post by Matlo »

Instead of running the Teensy at 3.3V, you should shift the voltage using a simple voltage divider.
http://gimx.fr/forum/viewtopic.php?p=4485#p4485
GIMX creator
mstrVLT
Posts: 8
Joined: Thu Jan 28, 2016 11:30 pm

Re: 16 MHz => 8 MHz for EMUPS4

Post by mstrVLT »

in datasheet AT90USB1286 (teensy++ 2.0)
Image
Baudrate 0% error on 3V
I think it's possible, i try. This way is better and easy than add divider or revrite firmware to arm
User avatar
Matlo
Posts: 5768
Joined: Wed Jul 06, 2011 7:01 am
Location: France
Contact:

Re: 16 MHz => 8 MHz for EMUPS4

Post by Matlo »

At 8MHz the AVR will execute twice less instructions per second.
It may still work, but you may also get timing issues.

Using a voltage divider is trouble-free.
GIMX creator
Post Reply