Best posts made by ahhk

Protecting your "home" starts first at the boundary. An alarm-system is the absolutly last option - the bad guy is already "in da house" then. Think about

• fences
• hedges
• lockable windows (dont let the keys in the locks)
• good neighborhood
• motion-sensors and bright lights...
• sticker on the windows (e.g. "house is protected")
• a dog (?), too.
• dont post on FB that you are on holiday

If you do a lot of those things, the internal alarm system can be very simple: Just put some movable motion-sensors in the corridor and important rooms in the ground floor and connect them to a very loud siren outside, to the smoke-detectors inside and to all the lights, rolling shutter you have....just let the house go crazy :D. There is really no need for a "professional" alarm-system for a private (single-family) house in my opinion.
greetings

Andreas

Hi all,

i searched and read a lot topics, but i am still not sure: Is it possible to run a NRF24L01+ directly connected to a Raspi and run a kind of "gateway" in software instead connecting an arduino to the Raspi? I would be happy to get rid of the arduino-ethernet-mqtt gateway...

I think i found a link to sourcecode where someone ported the libs to pi, but no manual about it (howto install,....)..

Maybe someone can give me a helping hand?
Greetings

Andreas

Hi all,

i was never happy with the arduino pro mini and i dont like smd (too small for me). I was inspired by another design and so i decided to create my own board with "normal" components. i am not sure if everything is right, because this is my first selfmade pcb-design an my first project with eagle. So, i hope you can take a look at it and tell me, if something is wrong or what i can improve.

This is the design:

And this is the board.

Some background-info: I want to design an own board for every type of sensor i need. In detail:

• 4x DS18B20 - powered with 3.3v-boost converter( seperate pcb)
• I2C connector for LCD or Temp-Sensor (HTU21D)
• Analog-Inputs for Moisture-Sensors
• PIR-Board

Here is only I2C-board. The other boards are nearly "identical" except pinouts...

Every board has the same basic-features:

• 2 LEDS (OK & Error)
• Debug-Port (TX & GND)
• Pinouts at same pcb-side (top)
  -Voltage Monitor included with solder jumper to chose input voltage. Reason: If the board is powered vi 3.3v booster, i need to monitor the raw-battery-voltage.

The board is designed with eagle and seeedstudio design-rule. So i will order them when i have finished the design....

What do you think about this?

Greetings

Andreas

Hi Gert,

thx for your feedback. Lets make a small structure to discuss the things:

Battery-monitoring
I plan to you use the AREF as 3.3v Reference powered by the step-up-module. I think most of my sensors will have a step up. So this should be quite easy and accurate. In this case i solder a wire instead of R1 and "unsolder" R2....
OR (if i really want) i can use the voltage divider on A0 instead (like mysensors.org says). I think with this schematics i have both possibilities... How does it work without resistors and internal vref (1.1v)? I only saw the version with 2 resistors on the mysensors page.
By the way: I tested 3 step-up-modules:

Pololu with NCP1402
Sparkfun with NCP1402
"China-Module"

The China-Module is crap (+-240uA).
Pololu draws +-100uA in sleep mode
The Sparkfunboard only draws +-30uA in Sleep mode. I will go for that.

Capacitors:
There is a capacitor between VCC and GND. The capa between AVCC and GND is missing, you're right. Thx.
I want to use AREF, so i cannot pull it to ground. Or what did you mean? Or am i missunderstanding something? I thougt AVCC is the supply voltage for the "REF"-function. And AREF is the reference-voltage....

Programming
In an updated version from last night, i moved the debugport to the topboard. I can upload new sketches via RX/TX...
Do you know if it is possible to use the ISP when the NRF24l01+ is still connected to these pins?

LED
I dont want to have a regular LED-blink (power consumption). It shall only blink when working(transmitting).
Green => All OK: Measures are ok, packet was sent
RED => ERROR: Measurement fails or packet could not be sent...
A DUOled would save some space, but no pins.

Sensors
I think i will have a max of 5 Sensors connected on one board , so there is no need to save pins whereever i can.
The I2C port is like the sparkfun "standard" I have a lot of HTU21D-BOBs laying around. They work like a charm

After i gave my child something to eat, i update and upload the schematics...give me some time

Next variant. Less flexible, but flexible enough. Boardsize now 50x30mm
It's only one pcb now and you can connect

• 5x sensors (digital or analog)
• 1x I2C and 3x sensors (digital or analog)

Step-up can be soldered to the bottom.

What do you think?

Hi,

sure i will share the brd-file and schemativ. No problem. But let me first build one working sensor. I think i will order the pcbs this weekend, because this looks good too =>