d-diot board v.2.0

franzunix

Topic dedicated to the d-diot board v.2.0 and to the assembly process of the hub v.2.0.

Troop

Hi,

First of all congrats for this fantastic project.
Can any one tell me if pcb source is avaliable or where can i get a pcb ?

Thank you.

franzunix

Hi Troop,

sorry for my late reply, very good question! I’m working on this aspect with PCBWay, so I will give you an update ASAP.

Let me take advantage of this post to say that the development of the d-diot board v.3.0 is in testing phase and it will be available soon.
This new version has some improvements respect to the v.2.0 especially when used with a Raspberry Pi 4, so keep it mind before starting with the 2.0 board.

Below a spoiler 😉 of the new board

Troop

Hi franzunix,

Thank you for the reply. In version 3.0 electric schema has been changed or it’s only pcb fixes ? Any ideia when version 3.0 will be released ?

franzunix

Yes, the board 3.0 is a different beast with some changes in the schematics. The main differences respect to the board v.2.0 are:

The power on / off state of the Pi is controlled by an ATMega328P MCU (or an Arduino nano as an alternative) instead of a latch circuit made with capacitors and resistors. So the board v.3.0 is compatible with the Pi 4 and it is future proof (see here to know more about the problem of the board v.2.0 and the Pi 4).
The external buck and boost converters module have been replaced with two on-board circuits made with common components (inductors, mosfet, diodes). The output voltage is controlled by the same ATmega328P MCU (or Arduino nano) that controls the Pi power status and it is regulated via software in the firmware.
Since the Pi 4 has more serial ports available on its GPIO, the second MySensors gateway (NRF24) now runs on a dedicated ATMega328P MCU (or on an 3.3V 8 Mhz Arduino Pro Mini as alternative) located in the right part of the board.
The on / off status of the FAN is controlled by a GPIO of the Pi and can be automated in Home Assistant on the basis of the CPU temp. This makes the hub more silent.
A connector for a separated set of IR leds (suitable for the night vision for a camera) controlled by a GPIO pin has been added.

I have ordered the board 3.0 last week, so hopefully I should receive the pcbs this week for testing. After that and an update of the d-diot image I should be able to make it available in the PCBWay bazaar

Let me say that, due to the use of the additional serial ports that are an exclusive of the Pi 4, the board v.3.0 is not fully compatible with the Raspberry Pi 3.
You can use it with a Pi 3, but without the second MySensors gateway (NRF24) and the 433 Mhz gateway (RFLink); on the hardware side this means that you don’t need all the components that are on the right side of the vertical white line in the picture above.

In any case I have some unused copies of the board v.2.0 that are simply collecting dust, so I can send to you one pcb. If you are interested send me a private message.

Troop

Hi franzunix,

Sorry for my late reply. Any ideia when version 3 will be avaliable ? It’s going to be avalible only as gerber or source?

Thank you.

franzunix

Hi Troop,

glad to hear from you again, hard to say now a precise date when the board v.3.0 will be available. In this moment I’m still waiting for prototype arrival for testing. If I don’t have done any mistake in the design of the circuit (at leat I hope so 😅 ) the testing phase could be quite fast.

My plan is to make the board available for direct purchase in the PCBWay bazar in 2 versions:

Pcb only
Fully assembled board (turnkey solution)

For the fully assembled board a small economic investment is necessary, so my idea about this point is to start a crowdfunding campaign with Kickstarter, while for the “pcb only” version the situation is a lot simpler.

Troop

Hi Franzunix,

How are you?
Any news on version 3.0 ?

franzunix

Hi Troop,

all fine thanks, hope the same for you!
Regarding the board v.3.0…. Tadaaaaaà, below the pictures of the first soldered prototype

What works:

Step up and step down voltage regulators, managed by the arduino nano

What is wrong:

The on/off management of the Raspberry Pi, handled by the Arduino Nano. Probably this issue can be solved with the firmware.
The voltage divider on the Out Pin of the IR receiver (TSOP 4838). It must be replaced with a pmos an pull-up resistor. Not a big issue but requires an update in the board design

Untested

Serial communication between the MCUs and the Pi
The new d-diot image

In the last two weeks I was on holyday, so I don’t have had too much time to work on the d-diot project, but during this time I have had the chance to think more in general about the direction of the project and now I think that it is time to share this conclusions with some other people, just to see if I’m in the right direction.

My considerations:

Home Assistant can run on different devices other than a Pi, like for example a standard PC, a virtual machine and so on…
Hass.io is more user friendly and simplify a lot of things
With Hass.io (at least the docker version) you don’t have a direct access to the Pi hardware (IR -> lirc for example), so it is not compatible with the d-diot board

My conclusions:

The d-diot hub should be compatible with all the devices that can run Home Assistant and not only a Pi
Switching to Hass.io is a good thing for the final user and also for me (no more d-diot images to build and mantain)
Building a hub with the same functionalities of the d-diot board (IR Gateway, 433 Mhz Gateway, Mysensors gateway), but in complaince with the other two points above is feasible and probably easier to assembly respect to the d-diot board.

The final idea:

Switch from the d-diot board to a standalone (= independent from the Pi) wifi multi-gateway (IR, 433 Mhz, Mysensors), using a bounch of ESP8266 and / or ESP32 modules

Of course any feedback about this point is well appreciated!