[NTLK] Designing an Internal WiFi Board for MP2x00

Jake Bordens jake at allaboutjake.com
Sun Mar 29 13:46:31 EDT 2015

It works!  Almost. :)

Full details are here: http://retronewton.blogspot.com/2015/03/it-works-sorta.html

Long story short, I hardware flow control doesn't seem to work and I'm not sure why.  It might be a software thing.  The module is powered on by the SerPortSel3 signal.  The Newton shuts that signal off on connecting to 'mdem'-- this powers off the WiFi module.  Maybe this screws up the negotiation of the serial port, not sure.

I have a history of getting the hardware flow control lines backwards, so if someone who's familiar with serial comms wants to check my work, it would be appreciated.  No matter how many times I double check or prototype, I always seem to get it wrong.

On the plus side, it does seem to work without flow control.  I'm able to connect to my WPA2 wifi network and ping my router using the AT+i command set.  I haven't tried using a NIE app with it yet, but it should work as a PPP server.  I already had the Newton "dialing up" to my WiFi network on the proto-board.

Still need to work on antenna placement.

On 2/2/15, 6:42 PM, "Matthias Melcher" <mm at matthiasm.com> wrote:

>> On Feb 2, 2015, at 11:13 PM, Jake Bordens <jake at allaboutjake.com> wrote:
>> So I've been slowly working towards a PCB design for an internal wifi 
>> board. 
>This is fantastic!
>I am not an EE, so this is just some spontaneous blurp of what comes to my mind.
>I believe that the serial port runs a CMOS level which can go up to 5V. Make sure that your module can take 5V at the input. Also, you may need a 3V-to-CMOS converter on the outputs.
>I highly recommend that you build a breadboard version first, but then again, I am quite sure that you did ;-).
>The NewtonTalk Mailing List   http://newtontalk.net/
>The Official Newton FAQ       http://splorp.com/newton/faq/
>The Newton Glossary           http://splorp.com/newton/glossary/

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