# IoT breakout board pin mapping

**URL:** <https://mangoh.discourse.group/t/iot-breakout-board-pin-mapping/289>\
**Category:** IoT Cards\
**Created:** [November 17, 2016, 6:08am UTC](https://mangoh.discourse.group/t/iot-breakout-board-pin-mapping/289 "2016-11-17T06:08:18Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Kas.Lewis](https://avatars.discourse-cdn.com/v4/letter/k/e9a140/32.png) [@Kas.Lewis](https://mangoh.discourse.group/u/Kas.Lewis)\
**Post date:** [November 17, 2016, 6:08am UTC](https://mangoh.discourse.group/t/iot-breakout-board-pin-mapping/289/1 "2016-11-17T06:08:18Z")

</div>

I have attempted to use the IoT breakout boards for debugging. The issue I am having is trying to understand how the through hole locations are numbered. With ~40 holes and only 20 numbers things don’t add up. Also teh mangOH board provides 38 connection points. Overall teh use of the IoT breakout board is unclear. With no top/bottom marking (this affects the pin mapping) and no clear way to understand what hole is mapped to what connection point it feels like a lot of walking around in teh dark. If there could be some explanation added to this simple board it would be very much appreciated and helpful.

Thanks  
Kas

---

<div class="post-metadata">

**Author:** ![asyal](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/asyal/32/78_2.png) [@asyal](https://mangoh.discourse.group/u/asyal)\
**Post date:** [November 17, 2016, 4:09pm UTC](https://mangoh.discourse.group/t/iot-breakout-board-pin-mapping/289/2 "2016-11-17T16:09:04Z")

</div>

Hi Kas,

Please see this post

> [@GPIO not working](http://mangoh.discourse.group/t/gpio-not-working/105):
>
> I’m trying to read the GPIOs, using the supplied gpioCf3 example as a basis. [http://legato.io/legato-docs/latest/sampleApps\_gpioCf3.html](http://legato.io/legato-docs/latest/sampleApps_gpioCf3.html) But it doesn’t work: I’ve set all the GPIOs as inputs with pullups, yet some of them read as zero! When I apply 0V or 1.8V (via 1k resistor) the values read do not change, and change event handlers are not called. The voltage at the GPIOs is ~ 0.3 - 0.4 V. For each input, the setup looks like this: //-------------------------------------------------------…

cheers,  
Ashish