This is a PCB that uses AC power to run a MySensors node inside a wall socket. The main goal is to have a MySensors node with I/O to be able to build your own node with your own sensors inside a normal (European) wall socket. It comes with PCB and a 3d box for protection and safety.
Current Status and revision
Larger AC and DC separation (<3.3mm, meaning you can only use it inside Pollution lev I)
Larger creepage/clearance between AC circuit (Minimum 2.5mm on AC side, allowed to use in Pollution lev II)
Safety recommendations: Always use this revision inside a sealed case or in an environment where contamination or moisture condensation not occurs.
Added label with license on board.
Moved voltage regulator to increase distance to AC side
Removed high voltage on silk screen
Added holes between AC ciriut to decrease creepage
Added lines on silkscreen to mark AC and DC gap.
For rev history, see Changes.txt
Note when buying through openhardware.io may say another rev. This is only revision for manufacturer, not current PCB revision. I always update PCB gerber files for sale first on openhardware.io
I designed this project for the main purpose of safely powering a node from a AC source. Battery operations and 5v phone chargers in all its glory but I needed a node small enough to put inside a wall-socket, adaptable/dynamic and AC powered.
We have AC mains running everywhere in our houses today and this project aims for converting AC to 5vDC with safety as priority #1.
Convert 240v/120v AC to 5v DC (using HLK-PM01)
Make it safe!
Fit inside standard appliance box / in wall
Run MySensors node (Arduino Pro Mini, NRF24L01+, MysX Gpio for sensors)
By using this you have everything you need for a AC powered MySensors node. With MysX connector you have plenty of options both digital and analog input/outputs for you sensors. For the AC power there are both a temperature fuse, a normal fuse, and a varistor to protect your node.
I wanted the node to be dynamic (no sensor specific) - and therefore the MysX connector. Now you can add any sensor you like to the connector. Also, while at it - why not add a relay. Since I'm going to use this around AC i might also be able to switch it in the same time.
Follow this thread for latest info: https://forum.mysensors.org/topic/2488/in-wall-pcb-ac-to-dc-5v and https://forum.mysensors.org/topic/2783/in-wall-ac-dc-pcb-for-mysensors
Build instructions coming soon, see BOM for more info.
Power - Using the HLK-PM01 converting AC 240/120v to 5v dc and running the MySensors node. The input is protected with a fuse, temp fuse and varistor (read this discussion).
MySensors - A Arduino Pro Mini and a Nrf24l01+ SMD Radio with all the normal components.
I/O - MysX 2.3
3d-box - A part of safety, attached is a .stl file with a case for 3d printing. This can be printed in your 3d printer or sent to a 3d-hub. (Coming soon!)
This is The MySensors expansion connector to which you can connect any daugherboard using this standard. This is also your main input/outputs for sensors and actuators so any wires can be connected accordingly. With this PCB as motherboard you can use draughtboards if you need multiple copies and needs a quicker way to build - just like a shield on Arduino or Raspberry Pi.
Safety is one of the most important aspects of this project! Se more here: https://forum.mysensors.org/topic/4175/clearance-creepage-and-other-safety-aspects-in-mysensors-pcbs. All revisions from and below 3.1 does not follow all this rules due to space and other limitations. It is highly recommended to use this inside a sealed box and never in a environment where pollution or condensation occurs.
Text below is written for the latest posted revision. For older revisions, please see changes.txt
My thoughts has been to separate AC (primary) and DC (secondary) sides completely. At this point this separation is to small and it is only recommended to use (for all revisions below 3.2) it in pollution level I only (No contamination or only dry, non-conductive contamination occurs. The contamination has no influence.)
Note: there has recently (Sept 16) been some fake/pirated HLK components! Warning!
As for the separation within the AC traces I have tried to use 3mm creepage and clearance but this turned out to be to hard. This PCB has a creepage distance on the AC side of 2.5mm. This means if you are using 240v you can put it in pollution level II Sames as above, don't use it outdoors and put it in a case.
If you order or use this you agree to and understand that the author is not liable for any injury or damage howsoever caused and that you use this PCB at your own risk. This is DIY and the author has not made any professional test. This product has not been marked with any certification marks and cant be guaranteed to compliance with any standards.
Total cost for one node is about US$8 where the Arduino and HLK-pm01 is about US$6,5 (See BOM).
You can actually cut/split the PCB between AC and DC side and get a normal 5v Mysensors node where you can attach sensors to MysX connector.
|- HLK-PM01 AC-DC 220V to 5V Step-Down Power Supply||US $3.99||(3.99/pcs)||https://www.ebay.com/sch/sis.html?_nkw=HLK-PM01+AC-DC+220V+t...|
|- 10 pcs Ceramic Slow Blow Fuse (2 alternative)||250V, 0.2A (50W)||US $0.99||(0,09/pcs)||Ebay: Ceramic Slow Blow Fuse 3.6 x 10mm Axial Leads 125V 250...|
|- 10 pcs Ceramic Slow Blow Fuse (2 alternative)||250V, 0.3A (75W)||US $0.99||(0,09/pcs)||(HLK pref: Maximum input current =0.2 A, Input current surge ; =10 A)||https://www.ebay.com/p/1349300269?iid=231765976267|
|-10pcs Thermal Cutoffs SEFUSE Microtemp Thermal||73degr C||US $4.99||(0,5/pcs)||TEST YOUR FUSES BEFORE USING THEM - YOU NEVER KNOW WHAT YOU GET!||Ebay: 10pcs Thermal Cutoffs SEFUSE Microtemp Thermal TF Cuto...|
|- 10 x Zinc Oxide Varistor 250VAC 60J 2500A 10mm||250VAC 60J 2500A 10mm||US $1.89||(0,19/pcs)||Ebay: 10 x Zinc Oxide Varistor 250VAC 60J 2500A 10mm|
|- 10pcs Arduino Pro Mini Compatible 5V||5V||US $18.97||(1,9/pcs)||Ebay: 10Pcs New Pro Mini atmega328 5V 16M Replace ATmega128 ...|
|- 10pcs NRF24L01+ 2.4GHz Wireless Transceiver||US $8.12||(0,81/pcs)||Ebay: 10PCS Arduino NRF24L01+ 2.4GHz Wireless RF Transceive...|
|- 10pcs LE33ACZ 5V-3.3V Step Down Regulator||US $7.95||(0,8/pcs)||Ebay: 10 PCS LE33A TO-92 LE33 Very low drop voltage regulato...|
|Capacitors||0,1, 1,0, 10 and 4,7uF|
|-20pcs KF301-2P 2 Pin Plug-in Screw Terminal Block Connector 5.08mm Pitch||US $1.23||(0.06/pcs)||Ebay: 20pcs KF301-2P 2 Pin Plug-in Screw Terminal Block Conn...|
|10pcs DS18B20 Dallas Temperature Sensors||US $7.10||(0,7/pcs)||Optional||Ebay: 10PCS DS18B20 DALLAS 18B20 TO-92 1 Wire Digital Temper...|