Easy/Newbie PCB for MySensors

This is a PCB for all beginners who want to quickly build the nodes described in the MySensors website! It can be used with regulated power or batteries and only have basic components. Its a PCB for all newbies that wants to do basic sensor/accuator nodes like myself out there... :)

This is the Nrf24l01+ edition of EasyPCB! If you want to use RFM69 transiever instead go here.

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Why?

So pretty much this PCB covers all the basic stuff documented in the MySensors website! This cuts my work with one node from a couple of hours (soldering wires) to 20min.

What?

Only easy to solder components (bigger components with legs) Only basic functions (Pro Mini, Radio, Input for sensors and if battery powered booster and voltage divider) Dynamic in what power you use (Battery, 5v or Raw pin). Some inputs for all the normal sensors used in the build section. 5x5 or 3x5 depending on function

How?

Battery 3.3v

5x5cm

The design is the design from by my forum post here but also much cred to @m26872 My 2Aa battery sensor design.

Please not that different radio clones behave differently depending on noice from the booster. A good quality booster is important or you might have to modify and test different input caps on the radio and/or try to filter the booster with different capacitor. A normal behaivour can be that you have to change the 4.7uF capacitor to a 47uF capacitor on the radio for example. Im going to do more testing in this area to provide some more advices soon.

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Regulated 5v

3x5cm (cut PCB)

  • Pro Mini 5v
  • Radio with 4.7uf Cap
  • 5v -> 3.3v Regulator with caps
  • Caps/Resistors/Pinhead (jumper)/Screw terminal (optional)
  • Sensors are possible to attach to the left (Gnd x 2, VCC, D3 (with or w.o resistor), D4, D5, A4, A5)
  • REG jumper should be soldered.

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(If you are using regulated 3.3v, use 5v instructions but skip the voltage regulator and bypass this with a jumper between Vin and Vout

6-12v to RAW pin

3x5cm (cut PCB)

  • Pro Mini 5v
  • Radio with 4.7uf Cap
  • 5v -> 3.3v Regulator with caps
  • Caps/Resistors/Pinhead (jumper)/Screw terminal (optional)
  • Sensors are possible to attach to the left (Gnd x 2, VCC, D3 (with or w.o resistor), D4, D5, A4, A5)

Input 6-12V to RAW (right pin - not VCC!) and the voltage regulator onboard the Arduino Pro Mini will regulate it down to 5v. You also need the 5 to 3.3v voltage regulator with capacitors to power the radio. Nu jumper needs to be shorted.

Be carefull using 12v to RAW on the cheap arduino clones! Due to bad/cheap voltage regulators on the clones many fails pretty fast. If you want to use 12v I would recommend using a genuine pro mini or regulate the voltage yourself and not let the clone do it.

Battery without step up booster (advanced users)

3x5cm (cut PCB)

To be able to achieve this you need to reprogram the atmega bootloader/fuses and lower the BOD!

  • Pro Mini 3.3V
  • Radio with 4.7uf Cap
  • Sensors are possible to attach to the left (Gnd x 2, VCC, D3 (with or w.o resistor), D4, D5, A4, A5)

  • Both REG and BAT jumper should be soldered.

  • Feed the PCB with 2xAA (or similar) to VCC

With both REG and BAT closed you will feed everything (Arduino, Radio and Sensors) with whatever voltage the battery holds. You can not use any sensors which require higher voltage than the current battery status (without DC/DC Step up booster). With this configuration you can use the internal VCC library to read battery status on VCC. Lowest working voltage (depending on added sensors) will probably be the radio which can handle down to 1.9v. Do not use any DC/DC step up booster or voltage regulator!

To lower BOD you can use standard Pro Mini bootloader and change boards.txt. See here for instructions.. This will give you some more battery (down to 2.2-2.4v? due to 8mhz) but using the 8mhz external crystal will be risky at low voltages (atleast at 1.9v, radio minimum) so it might be a good idea to run a bootloader @ 1mhz interal oscillator.

PCB Dimensions

5x3cm for cut PCB/regulated voltage and 5x5cm battery operations with extra prototyping space.

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Jumpers

  • BAT: Short this if you are using batteries as power supply. It will activate booster circuit and feed the radio directly from the batteries and not voltage regulator

  • REG: Use this if you are using 5v regulated DC. It will power the radio from the voltage converter.

  • RAW: This is a MysX feauture. This cuts onboard Vraw source if daughterboard provides Vraw. This is only used when EasyPCB is connected to a daugheterboard.

  • IRQ (Radio): Pin 2 on the arduino is disabled so you can use this for interupts instead of the radio. Most of the time this pin isnt used by the radio, so therefore disabled. If you want to enable this pin you can connect this jumper.

Boxes / Enclosures

  • Here are images of a great box by @dbemowsk which fits EasyPCB + 2xAA and it can be found on thingiverse

  • Also a great box by barbuino here.

Revision changes

Rev 9: 13/12-2016 (Tested)

Changes:

  • Bigger mounting holes 2.5mm
  • IRQ Jumper from Radio. This makes this trace disabled and D2 can be used for interupts unless jumper is connected.
  • BAT and REG jumpers changed positions for better tracing.
  • MysX 2,6 (Note this input for the sensors are changed from prev rev!)
  • Text on voltage regulater (Vout/Vin/Gnd)
  • Bug with G on CAP now on the right side.
  • GND and VCC swapped - so you could use a 2 pin block for GND/RAW as well.

I want it!

  • Order 10pcs: openhardware.io (Recommended!) and support me and MySensors! (It may say another rev. at the orderpage but this is not EasyPCB rev but the rev for manufacturer. I always update the gerber files for sale! Current = Rev 9)

  • Download from this page to get Eagles and Gerber files. Note that the gerber files are run with Itead cam job.

  • If you want a faster shipping time or less pieces you can buy them from me via Ebay.

Notes

All free to use as open hardware but I like if you tell me any cool project you make with it :)

All feedback welcome! The main goal is to keep it as simple as possible though.

Inspiration:

https://1drv.ms/f/s!Ak7D1EWM7GXggetbxu1hqsXgaaZy4Q

(Note some photos are older revision of the PCB)

Projects

QnA / FAQ

Q: What is the battery life on 3.3V and booster? A: Depending on what sensor you wish to run and how frequent you want to get data! One example: DHT22, sleeping 15min and sending Temp/Hum with a china/ebay booster is about a year. You need to desolder the led and voltage regulator on the Pro Mini 3.3v and use sleep() mode to save power.

Q: Why is the radio sticking outside the PCB? A: Having metal close to the radio antenna will likely mess up the reception.

Q: Both Arduino and NRF are capable of operating down to about 2V. Why do we need the booster in battery operation. A: To be able to use the pro mini down to 2v you need to mess with the fuses which inst needed now (more newbie friendly). Also some sensors might require 3.3v

Q: What is the IRQ jumper for? A: IRQ (or D2 on the pro mini) can handle interrupts and isnt used in all transceiver operations (not always needed). So this way you can choose to use IRQ either as interrupt or for the radio.

Q: Will it work with all Arduino Pro Mini? A: No - only with the same footprint (most common) used on the PCB! Look here.

Q: What is the purpose of the Raw connection under the radio connection? A: Its a criteria of the MysX connector - to be able to switch RAW on/off from a daughter pcb. You dont have to think about it until you have a mother/daughter board.

Q: How could I connect radio's power input to boosted powering source to get stable 3.3v? A: use regulated power instructions instead. Set the jumper on "reg" and bypass the voltage converter with a wire. Whats good to know is that this has been tested over and over in this forum and the conclusion has been so far that if you run with 2xAA the best solution is to bypass the radio in the booster (i.e. use battery instructions - hence the difference). The radio can handle down to 1.9v so it wont die for a long time if you have some power savings in use. The booster might also cause noise and reduce its efficiency/range.

Q: Is it possible to use 5v mini + 9v battery with measurement ? A: Powering it through RAW is possible but if you want to use the booster and battery measuring this is not an option , you need to power it through PWR and BAT jumper. I think what described here is possible but untested. First you need to find/create a booster that can handle the battery. Also you need to make corrections on the voltage divider(47k and 67k?) for the battery measuring and also code changes. Please share any test with this.

Q: When i use a 3,3V mini then i do not need the 3,3V regulator and it is powered with a battery. If i use a 5V mini then i need the regulator. Is this correct? A: Correct statement. The radio cant handle 5v.

Q: Do i need the booster if batteries are used? A: No, you can bypass it with a jumper/wire - but it will give you alot of extra. Without the booster the arduino 3.3v will die somewhere between 2.8 and 3 volts, with booster you can go down to 1.9v.

Q: How about the RAW option? How does it go to 5V? i need the regulator to go to 3,3V so how do i loose the 6-12V A: There is a voltage regulater on board the pro mini that handels from 6-12v (be cautious using 12 v, 9v is max i recommend on clones). This will convert your RAW to 5v and provide the board with this. Then the external regulator will go from 5 to radio 3.3v. You could use a 12 to 3.3v regulator outside the PCB and use the 3.3v REG option.

Q: How do I access A2, A3 and D8? A: They are not accesses through the PCB, so you need to directly solder to the pro mini.

Q: What's the 0.1 uF capacitor next to the battery terminals/voltage regulator for?? A: Its to maintain stability of the voltage regulator. If you look at different datasheet most voltage regulators has a typical application schematics where different capacitors is added before and after to make this. So the 10 and 0,1uF work together. Why 0,1 and 10? Well - I have seen this setup on the forum many times so I just went with that. There is alof to read about this, but I think the smaller cap can react faster while the bigger cap have more juice to give so to say. The capacitors are NOT needed if you doesnt use a voltage regulator.

Q: Why is the headers (MysX) for the sensors different between Rev 8 and Rev 9 A: One of the reasons I upgraded to Rev 9 is because MysX came out with a new version. MysX 2.X (which is used in Rev 9) has access to alot of better pins so I descided to upgrade to this. On previous EasyPCB rev (<9.0) I use MysX 1.X

Q: Can I use any other batteries than 2xAA (3v) ? A: Yes - but the voltage needs to be regulated to fit the hardware on the board. You also needs to update the voltage divider to fit your battery voltage if you want to measure battery status (and using booster). Here is a example of 5.5v project with a voltage divider reading voltage status.

Images

Design Files

NameSize# Downloads
CHANGES.txt2.58 kB475
COPYRIGHT.txt421 B265
SundbergMys9.GBP28.85 kB263
License.txt8.94 kB290
SundbergMys9.GML28.85 kB273
SundbergMys9.GTL36.61 kB249
SundbergMys9.GTO174.55 kB244
SundbergMys9.GTS31.82 kB244
SundbergMys9.TXT1.92 kB296
SundbergMys9.brd289.78 kB371
SundbergMys9.GBS31.82 kB253
SundbergMys9.sch360.13 kB346
SundbergMys9.GTP28.85 kB211
SundbergMys9.GBO28.85 kB244
License_howto.pdf55.06 kB404
PRODUCT.txt113 B432
SundbergMys9.GBL36.86 kB264
SundbergMys8.brd289.34 kB497
SundbergMys8.sch361.97 kB511

Bill of Material

QtyDeviceValueDescriptionLink
1Arduino Pro Mini3.3v 8mhz or 5v 16mhzDepending on operationhttps://www.mysensors.org/store/arduinos
1DC/DC Step up boosterIn: 0.8 – 3.0 Out:3.3vUsed if you power with batteries (make sure you have a good quality booster, or noice will interfere with the radio)https://www.mysensors.org/store/regulators
1Voltage regulator5v to 3.3vIf you input 5v and using 5v arduino.https://www.mysensors.org/store/regulators
1Nrf24l01+ Transiever2,4ghzThe radio!https://www.mysensors.org/store/radio
1Capacitor throughhole10uFC1 - If you input 5v and using 5v arduino with a voltage regulator.https://www.mysensors.org/store/components
1Capacitor throughhole0,1uFC2 - If you input 5v and using 5v arduino with a voltage regulator.https://www.mysensors.org/store/components
1Capacitor throughhole4,7uFC3 - For the radio, can be adjusted to remove noice.https://www.mysensors.org/store/components
1Capacitor throughhole0,1uFC4 - If you are using voltage divider to measure battery levelhttps://www.mysensors.org/store/components
1Capacitor throughhole0,1uFC5 - if you are using booster (optional, good with cheramic)
1Resistor throughole1M - OptionalR1 – This is used for a voltage divider to measure bat. Levelhttps://www.mysensors.org/store/components
1Resistor throughole470k – OptionalR2 – This is used for a voltage divider to measure bat. levelhttps://www.mysensors.org/store/components
1Resistor throughole10k - OptionalR3 – This is a pull-up resistor for D3https://www.mysensors.org/store/components
1Screw terminal5,08 spacing - OptionalTo make it easy to attach power/ground.Ebay: 20pcs KF301-2P 2 Pin Plug-in Screw Terminal Block Conn...
1Pinheaders/Jumpers2.54 spacing - OptionalTo attach dupont cables and make jumpers (can be soldered directly)https://www.mysensors.org/store/cables

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