RS232 IoT Expansion card - where can you get one?


There don’t seem to be any vendors supplying them. Are they released yet or is there any plan to release them soon ? I mean production modules. If no production modules, how about schematics ?

PS Renfell, who are linked to on the Sierra Wireless website, do advertise on but all attempts to contact them have failed, they don’t respond to emails and there is a problem with their web-query javascript.


I have e-mailed Renfell with a link to this forum post.


Thanks. If they’re going to be reading this, then the problem with their website javascript contact form is that it only accepts Australian telephone numbers…


I can see that or (they are one and the same) have them avilable $7.74

I hope that helps





Kas, thanks for the suggestions. Those boards you linked to are breakout boards, not rs232. It’s not for a mangoh green which has rs232 on board.



Apologies for the delay in getting back everyone. And apologies for the bug on my contact form - I’ve just fixed the form to take overseas phone numbers.

IoT cards are available now: RS232, RS485 & IoT Interface breakout. Only available direct from me at the moment.

Either use the contact form ( or PM me here on the forum and I’ll get back to you.

ciao, Dave



Expansion cards are now available form Linkwave Technologies in the UK:

ciao, Dave

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Hi Dave,

Thanks for that. Littlesliceofmangoh is very good, btw.