Hard or firm diferences betwen n2 and n2+ problem

Hi sirs, again need your help a khowledge…

I would need some help with a problem I am encountering and it is this:

I have a N + with firmware and a N2 + in which I recently installed (thanks to the indications of the community) to version because I am working with VS2010.

The application with N + works correctly but with N2 + no. Specifically I have an RS232 shield that sends information.

I would like to know if any firmware or hardware differences between N + and N2 + could be the cause of this happening.

I have tried using COM1 and COM2 but the problem continues.

Apparently the transmission takes place but the data is not sent.

The RS232 shield used is the LinkSprite shield.

In case the problem is firmware, is it possible to install version in N2 +?

Thank you in advance for your always attentive collaboration.


Just another thing checked

Netduino plus hardware has 0 to 7 pins pulled up to 3,3V, Netduino plus 2 no… Could this be the reason?

Thanks in advance.

The N+ pins were pulled high on reset, I think the N2 later boards were pulled low on reset.

Do you have access to a logic analyser or a scope to view the output from the com port?

Wild guess but wondering if a pull-up resistor would help… It is a wild guess though.


Thanks for the answer Nevyn

I will check with a scope and also try with the pull-up.

Accidentaly check that if RX wire is not connected to the shield the transmission works ok, if is connected, the shield´s MAX232 goes very very hot, any idea?

Thanks in advance

Do you have a schematic we could look at? I’ve never have the MAX232 get hot.

Sounds like there is something wrong.


Hi Nevyn,

Thanks a lot for your help.

Information about the shield here


With N+ works ok, with N2+ without RX pin works ok, with N2+ wi RX connected max232 get hot, very hot.

The device connected is an Epson printer TM-88V

Thanks in advance.



Is there any way to pull-up / down pins on reset?