Today.... This MQ2 gas sensor with Neopixel RGB lamp on top and a capacitive touch button under the circle mark on the front.
It is part of the d-diot project. The files of the 3d-printable case are available in Thingiverse.
The firmware is available here, the wiki page is under construction.
In the next weeks I will try to print it in wood... Just to increase the WAF 
@nca78 
thanks for the info! I have seen that the Anycubic resin is available also in big online stores like Amazon, so fast delivery time guaranteed.
@NeverDie: Unfortunately the fragmentation is the dark side of the moon of the open source world, but in my opinion the quality of some project here is really awesome and above the average, so it is a shame that they don't have the adequate visibility. In addition in this last months some big pcb manufacturers like JLPCB have included in their offer an assembly service, so, with the adequate visibility and documentation, the entry barrier for new users in the DIY home autmation could be not so high.
@berkseo The "marble" case is very cool! The filament is easy to print or requires some special parameters? For example in this days I'm fighting with a wood filament, below the results
Dear makers,
after a lot of learning and some tentatives, I have finished my d-diot project.
Basically it is a board that sits on top of a Raspberry Pi and has the following features:
Latch circuit to turn on and off safely your Raspberry Pi with the SW1 button.
Infrared receiver and transmitter with activity LEDs.
USB port to add extra infrared transmitters (or simply charge your phone).
DC power jack and power status LEDs.
433 Mhz Gateway (RFLink) with the Atmega2560 microcontroller and 433 Mhz radio modules (FS1000A and RXB6)
MySensors dual Gateway with NRF24L01 and RFM69 (868 Mhz) radio modules and radio traffic LEDs.
I2C OLED Display (SSD1306) controlled through Raspberry GPIO.
FTDI and ICSP connectors to program the ATMega2560 microcontroller.
Step-up and step-down voltage regulators.
Fan pin header.
Footprint for optional high gain 433 Mhz and 868 Mhz antennas.
A pre-configured Raspbian image image with Home Assistant and MySensors is also part of the project.
In the d-diot wiki you can find a detailed description of how I have configured the Raspberry to support two radio modules.
Maybe this can be usefull for some other people.
If someone is intersted on the project, well simply contact me.
Any comment or suggestion is well appreciated.
Found a solution! It is quite easy with the custom board features of PlatformIO.
I wrote a brief tutorial here.
Tested with a Pro Mini 8 MHz 3.3V and FTDI programmer.
Unfortunately I don't have here a 16 MHz 5V devices to test
@zboblamont A cheap and silent alternative could be one of this qotom mini pc.
I'm using one of this as a virtual machine server with proxmox since 2-3 years and I'm very happy with it.
One of the vm is running pfsense so it act also as a main router / firewall for the entire Lan.
The backup of a vm is super easy but the initial setup of the environment requires a bit of Linux learning
@tbowmo Thank you for your effort! Now my turn... the whole schematics of the d-diot board is available for download here!
Of course I have to learn more and do some testing before implementing in the d-diot board the constant current source circuit that you suggested, but this a great option to eliminate the MP1584 (that one day may become unavailable on the market) and to lowering the cost. For the same reasons my plan is to substitute the step up module MT3608 with a boost converter circuit, made from standard passive components (like this).
In any case, if someone else needs to make an universal IR remote with a Raspberry Pi, the configuration of the GPIO pins of the Raspberry is here, while the steps necessary to configure LIRC and lirc_web are here.
The final results is this:
Here the guides to play with the IR gateway (add a remote, clone a remote, Home Assistant integration)
Hi, to power a sensor or actuator with a 18650 li-ion battery I have designed this pcb based on a tp4056 module and MT3608 booster.
Schematic:
Main features:
Load sharing circuit to safely power the load while charging the battery
Boost converter MT3608 (optional) to increase the output voltage. To reduce the size of the board the right part delimited by the vertical white line can be cut out
Charging status signaling led (optional)
Voltage dividers (optional) to measure Vin - V batt - V boost - V standby. Output available through J4
Battery reverse polarity protection through mosfet Q4, excludable through jumper JP3
Battery voltage measure point can be selected through jumper JP2
This board can be used with this one
I have ordered it (JLCPCB) but yet tested. After that if someone is interested I can share it through openhardware.
Any suggestion / improvement / comment is well appreciated.
@เธฃเธญเนเธฃ-เธญ I have a similar need, but not exactly the same.
My power route is:
18650 Lipo (2.7 - 4.2 V) -> TP4056 (charger) -> Booster (5V) -> Raw pin of pro mini 3.3V -> Vcc of pro mini 3.3V -> Radio (NRF24)
In my case the easy newbie pcb is not directly suitable because the Vout of the Booster is connected to Vcc instead of raw.
So my idea is to use a modified version of the easy newbie pcb with the schematic posted here
in order to have more flexibility in the power options.
Actually I don't have the skills to design a pcb, but maybe, if the idea is good, someone else could design it.
This schematic is compatible with all the power options actually supported by the easy newbie pcb, and supports also new possibility, simply changing a couple of jumpers
@tbowmo Yes I know and I'm a big fan of the open source too, since I discovered and started using Linux (it was way back in 2006 
).
As a result, the d-diot project is open and free in all its own software parts: for example all the configuration steps, script (oled), hack, tips and tricks are documented in the manual installation section of the wiki.
Opening the hardware completely in this moment is not so easy as for the software part because, as said above, selling some boards is the only options that i see to keep the project sustainable and self-sufficient from an economical point of view (hosting cost, test new pcb, buy the hardware, etc...).
Of course opening the hardware could improve the development with the contributes of other people, so I don't exclude this possibility for the future; at the same time sharing some schematics parts is not so dangerous, so to answer to your question about the step-up voltage regulator MT3608, see below:
The scope of the MT3608 is to power the FS1000A radio module (433 MHz transmitter) at 10-12V, to increase the range of the signal. The MT3608 is not strictly necessary because you can power the FS1000A with the RX3 PIN of the ATMega2560, bridging pin 1 and 2 of the jumper 5 (JP5). All is explained here.
The step-down MP1584 must be set to 1.5V if it is used to power one or more 940 nm IR LED (3W - 700 mA). The details are here, below the schematic:
The ir-pulse rail is connected to the pin 2 (+) of the J4 connector and to the D- pin of the USB port. A single IR LED is connected to the J4 connector, but if you want to increase the coverage of the IR signal you can connect 2 or 3 additional LED with the USB port. Please note that the MP1584 is rated at 3A.
The V-REG-OUT rail is connected to the D+ pin of the USB port.
Regarding the power rails, 5V is the main voltage provided by the power supply (+5V-IN in the schematics), while for the 3.3V there are 3 different lines, to not overload the voltage regulator of the Raspberry Pi:
Line 1: provided by U2 (AMS1117 and its caps) and dedicated to power only the NRF24L01. In this way we have a voltage as smooth and stable as possible, to avoid problems with sensitive radio module.
Line 2 (RAW): provided by U6 (AMS1117 and its caps) to power the radio activity and power status LEDs
Line 3: provided by Raspberry Pi GPIO and used to power the RFM69 radio module.
@skywatch Thnaks!
The main goal of this board is to offer a simple way to build any kind (RFM69 and NRF24 support, MYSX connector) of compact battery powered node.
Today I have finished the first node based on this board: a door window sensor (reed switch).
If someone is interested, here the detailed build instructions.
The next node based on this board will be a soil moisture sensor!
Hi guys,
in order to facilitate the development of any kind of battery powered sensors (or actuators), I have designed this small pcb that can be easily placed in a 3d printable case
The main features are:
Small dimensions: 55 x 35 mm
Multiple power options: 2 x AAA batteries or 1xAAA battery (Rechargeable or Alkaline), 1 x CR2032 battery, standard cellphone charger at 5V through the micro USB port or through Vin and GND pin of the MYSX connector
Reverse polarity protection (Mosfet Q1) to prevent damages in case of wrong batteries insertion.
Boost converter (ME2188C33) to increase the battery voltage to 3.3V when necessary
LEDs for radio traffic and low batteries signaling. All configurable in the firmware.
Multiple radio module supported: NRF24L01 (SMD and THT) and RFM69.
Footprint for a reed switch
MYSX connector v.2.6
Support for ATSHA204 chip (security and signing)
Mounting hole for a M2.5 screw
Probably in this days the ATMega-328P is a sort of "old" technology but for simple battery powered devices it remains a good option, also for its easy of use.
If someone is interested, all the informations and the links to technical files (kicad project, gerber, schematics, firmware, etc) are in the dedicated wiki page of the d-diot project.
Hi guys, thanks for this release! Tested with a Pi 4 and a dual ethernet gateway (RFM69 + NRF24): it works!
My /boot/config.txt is here.
Here a guide with video... very nice ! Probably a dirty job, but feasible in a garage and this technique could be useful when you have to make multiple copies of the same object.
@berkseo: thanks, I'm quite happy with the final result. I will publish the build instructions and all the related stuff of the mood lamp in the d-diot website, hopefully before the end of the year. It is based on an ESP8266 (with a custom PCB) and the firmware is generated with ESPHOME, so MySensors is not involved.
For the base of the lamp, which is printed with a wood filament, I have had to change the nozzle of my printer from 0.4 to 0.6 mm.
@nca78 thanks for the info! I have seen that the Anycubic resin is available also in big online stores like Amazon, so fast delivery time guaranteed.
@NeverDie: Unfortunately the fragmentation is the dark side of the moon of the open source world, but in my opinion the quality of some project here is really awesome and above the average, so it is a shame that they don't have the adequate visibility. In addition in this last months some big pcb manufacturers like JLPCB have included in their offer an assembly service, so, with the adequate visibility and documentation, the entry barrier for new users in the DIY home autmation could be not so high.
@berkseo The "marble" case is very cool! The filament is easy to print or requires some special parameters? For example in this days I'm fighting with a wood filament, below the results
@nca78 yes I know that the resin is toxic and unfortunatly another drawback is that you have to wash (with IPA) and cure your parts after printing. For sure not so easy and "safe" like a normal FDM.
But guys... There are a lot of interesting finished projects (pcb+case+firmware), what about a dedicated section and a standard way to collect and present them, maybe with detailed build instrunctions?
This may be helpful for new users but also for more experienced people that have to not reinvent the wheel every time.
For example I have tried something like this with my multisensor and Gas sensor.
@berkseo the final result of your SLA printed part is impressive. In the picture it appears smooth like a part obtained with injection molding.
Probably for small electronic enclosures a SLA printer is better than a FDM. It's Christmas time... I have to consider the idea to buy one
Amazing! 
The case is 3d printable?
Hi guys, project finished! Now the led are under the Fresnel lens, so the design of the case is more clean (WAF +10 
).
The final result:
With 2 x AAA batteries and the RFM69 radio module the node works very well and the total cost of the parts is about 10โฌ.
If someone is interested, here a detailed build guide, with the links to all the parts of the project (3d model of the case, Kicad project, gerber files, BOM, firmware).
Hi, if someone needs more info (debug, log, etc...) I'm here.
I can perform tests on Rpi 3 and Rpi 4 (Raspbian Buster) with NRF24 and RFM69 radio modules and then report the results. Not so much but maybe this can help the development.
