Which HAT do I need to build this IR transmitter?

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1

Hi,

I own a Raspberry 2 B+ and I’m about to build an IR transmitter to replace my remote. The project and the schematic are presented in details here : http://alexba.in/blog/2013/06/08/open-source-universal-remote-parts-and-pictures/.

I need direct access to gpio pins. So, I think that excludes Explorer Hat/Pro. I was thinking to get the Propeller HAT because it seems to give access to direct gpio pins, 5V vcc and 3.3V vcc, and that’s all I need. But I just want to be sure before placing my order. Will it work ? Or should I get an Adafruit T-Cobbler with a classic mini breadboard ? I’d rather go with the Propeller HAT as it fits perfectly in the pibow coupé. I don’t want a breadboard hanging around my RPi.

Thanks in advance for your help !

2

Hum, a HAT, by definition, does not allow direct access to GPIO, as the specs do not cater for stacking. Some however, like the Explorer/Propeller, do indeed provide a breakout for some of the pins, but not all.

I’m confused though, why would you need one of those HAT involved for your project?

3

I just want a hat because it fits perfectly on a Pibow Coupé case.

If I get a breadboard ad a Cobbler, it doesn’t fit on a pibow coupé case and it will hang around, it’s just not practical under my TV. Unless there is seach a breadboard that fits on a case ?

4

iMO, you really shouldn’t build a permanent solution on a breadboard, wires are bound to get loose.

These will provide clear from the USB/Ethernet ports if that is what you mean by fitting the Coupé:


or
https://shop.pimoroni.com/products/protopal

You could even stick a breadboard on top if you really wanted to, though again, soldering in permanent position is what will give you the least trouble long term.

5

Ok then, I will listen to you and I will solder directly on adafruit Perma-Proto. My main concern is that if I wrongly wire the schema, will I be able to undo and solder again or I need to buy another Perma-Proto?

Thanks

6

Desoldering single points is not that much of a problem. I haven’t tried the perma-proto myself but expect the contacts to be high quality and survive such treatments.

7

You only need the ‘No EEPROM’ version incidentally. In fact you might want to consider using a stackable header such as:

That way you can add an Unicorn HAT or some other HAT at some point. Depends how tall your IR is though, but could work.

8

Thanks RogueM for pointing me this link ! It’s nice because I do not solder directly on the Raspberry but on that HEADER, right ?

I will also get a breadboard for testing out my connections before soldering directly on the pcb. Gosh I haven’t soldered anything since my studies, 10 years ago !

9

No, you’d still use the perma-proto breakout to access the GPIO you need, but using a header with extra tall pins allows you to stack a HAT on the top of your IR circuit if you wanted to at a later point.

… That’s just a suggestion though, since you have a choice of which header to solder to the perma-proto. Soldering the header that comes with it will be slightly easier, but this will give you room to expand.

10

Sorry, I misspoke what I wanted to say. I thought that HEADER would clip directly on the RPi, and then I would solder my perma-proto on it, rather than soldering the perma-proto on the RPi itself.

Sorry for the spelling mistakes, I’m a french guy ;-)

11

Oh, yeah, I wouldn’t recommend soldering directly on a RPi2.

… I speak French btw, so if you get stuck feel free to PM me, though your English is perfect :-)

12

Oh thanks :) I think it’s better to continue here for sharing informations to those who face the same questions, even if it would be way more convenient for me to speak in french :)

So, to sum it up, I need :

  • The HEADER that connects to the RPi - no soldering required. It allows the HAT to be placed on top of USB/RJ45 port
  • The perma-proto hat - need to be sodered to the previous HEADER

Is that right ? Though I’m wondering why I would need that particular HEADER as it seems that there’s already one bundled with the perma-proto hat mini kit. In fact, I don’t plan in the near future to stack other hats.

And finally, would that fit in the Pibow Coupé ? Or I need to let my RPi naked ?

Thanks for your helpy mate.

13

Yes, the perma-proto comes with a header. If you don’t plan to add a HAT then the other one is not necessary. Be aware that you will not be able to desolder a 2x20 header later on though.

The pibow Coupé brings in no particular physical restriction, from the point of view of access to GPIO or attaching add-on boards it is very much like having a bare RPi.