openHAB hat for raspberry pi, any takers?

Hello everybody!

Im currently working on the hardware layer of my openHAB system, there´s quite a few bells and whistles missing from the raspberry pi hardware that i feel i must add.

So im considering designing a printed circuit board HAT, to integrate RF transmitter/reciever, IR transmitter/reciever, i2c bus, temperature sensor and some sort of display, possibly with a arduino as intermediate hardware layer.
And just for kicks, possibly even a NeoPixel LED or two, because what modern computer is complete without RGB LED´s?? :wink:

Now, the minimum order of such a PCB would be 5x and would cost somewhere around 2-5€/piece plus components and shipping.

So my question is; would anybody else be interested in a HAT (raspberry pi expansion PCB)?
I havent started with the proper hardware design yet meaning the feature list isnt fixed, so if youre interested AND is willing to pay for a unit, feel free to drop a feature request in the thread.

Do note; i am NOT a business, just a DIY-dude, so i will not be charging any extra for the units (my cost = your price+shipping(from sweden)) but also: i will not be offering any warranties.
I prefer to send the PCB´s unpopulated, but i can, for a cost, solder and test the PCB before shipping.
Estimated delivery would be in about 2-3 months (worldwide).

Current hardware feature list:

  • headers for 433mhz FM transmitter/reciever pair
  • header for DHT-11/22 temperature/humidity sensor.
  • header for stereo audio sockets (headphone connectors), for external IR reciever/transmitter (LIRC-compatible)
  • header for I2C-bus
  • header for SPI Nokia 5110 display board OR I2C LCD (16x2 char and 20x4 char)

Possible hardware features:

  • integrated Arduino Nano, to be used as input filter ( for the 433mhz reciever and IR reciever ) as well as display driver (receive display data from raspberry via serial and/or I2C and present it on-screen).
  • headers for a few (2-3?) NeoPixel (WS2812) 5mm LED´s
  • features requested by other purchasers.

I did order all of the above mentioned hardware components a few years ago off ebay, and the total cost for this project (including the possible features list) is about 25-50€ but its all optional, if you dont want a display for instance, just dont connect it… :slight_smile:


Could you please translate that?


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hehe Thanks for the translate! :slight_smile:

Im not sure a blinkenlight would be of much use to most but if someone would really REALLY want that, the MCP23017 offers 16 I/O pins and you can have up to 7 of them; 16*7 = 112 status leds, individually controlled.
If that´s not enough, a Arduino is capable of software-based I2C bus, besides the hardware-based bus, so in theory, you can operate at least 2 individual I2C busses (probably 3 or 4 at least), allowing you to control several hundred LED´s individually.

The MCP23017 is connected via I2C and is 5V compatible, but 112 LED´s are probably more than the raspberry can handle without external power…

I can help with the PCB design of such a blinkenlight, but i will NOT be ordering/soldering such tomfooleries… :stuck_out_tongue:
…its a repetitive strain injury (RSI) waiting to happen… :slight_smile:

So i prefer a human-readable text on a tiny display for system status… :slight_smile:

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