[Arm-netbook] apologies

joem joem at martindale-electric.co.uk
Tue Nov 12 22:45:41 GMT 2013


On Tue, Nov 12, 2013 at 7:51 PM, joem <joem at martindale-electric.co.uk> wrote:
>> Try this :) it popped up on Google pretty quickly -->
>> http://www.hobbytronics.co.uk/schottky-logic-level-conversion
>
> : awesome.  done.  added to spec.
>
> Same problem - access to the 3.3V power line inside the EOMA needed.

| no it is not.  TTL 3v logic is somewhere around 2v for low. a small
|reduction (such as using another shottky diode) would be enough.

> Anyway - 3rd diagram added - modified version of Henrik's diagram for the EOMA:
> http://www.gplsquared.com/eoma_boot/eoma_boot.html#uart_repair

| great.  1.8+3.3=5.1 so the pull-up would be to 3.23V - enough to be
|definitely below 3.3v.

Hmmmppp... pull ups don't work like you would expect
under certain circumstances. I'm removing the 3rd diagram from here:
http://www.gplsquared.com/eoma_boot/eoma_boot.html#uart_repair



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