Mini Lora Node, Arduino Mini LoraWAN sensor
At the begining this PCB has been created to help wiring between Arduino Mini and RFM95 Lora module and to be able to put the whole thing powered by various Batteries type (AA, 18650, A, ...).
Then I decided to add some funky stuff like:
new in V1.2
- Footprint for Ultra Low Power controller TPL5110
- R9 1206 or PTH Footprint to easily change resistor and thus delay between wake
- renamed silk pin to function instead of arduino name
- Optional Tactile Switch to wake from TPL5110
- Easy to build and solder, 0805 or PTH components
- I2C connector (or grove) to be able to add internal/external sensors such as BME280, SI7021 or HTU21D
- Footprint for Lora RFM95
- Footprint for a Microchip 24AA02E64T EUID
- RBG Led
- Optional Tactile Switch
- Various Battery Connector and type AA/A/18650/CR123
- Two A4/A5 pins position so you can use different Mini Clone (see BOM)
On version 1.1, I2C A4/A5 (the ones bottom right) are not connected, thanks to tkerby who detected this point on issue #1. This is now fixed on version 1.1a. Pcbs.io PCB have been updated.
No specific documentation for now, it's just a kind of wiring helper as follow
Arduino Mini RFM9x Module A0 <----> RST MISO (D12) <----> MISO MOSI (D11) <----> MOSI SCK (D13) <----> CLK SS (D10) <----> SEL (Chip Select) D2 <----> DIO0 D7 <----> DIO1 D8 <----> DIO2 Arduino Mini Shield PCB D3 <----> Push Button (Has Pull Down) D9 <----> Led Red D6 <----> Led Green D5 <----> Led Blue A1 <----> DONE of TPL5110 (to indicate we done) A2 <----> DRVN of TPL5110 (pulse out to wake CPU) SDA (A4) <----> I2C SCL Connector SCL (A5) <----> I2C SDA Connector
R9 determine Wake Time interval from TPL5110 as follow
- 170K 2 hours
- 120K ~1 hour
- 100K ~35 min
- 47K ~6 min
If you're using Battery clip connector, please isolate the A4/A5 and FTDI (V1.0 only) pads from clip because it will do shorts and prevent I2C to work.
I'm Using the LMIC stack as his with custom sketch, this one is under NDA for Ultra Low Power, So I can't provide it but you can use the one in example of LMIC.
You may need to disable debug of LMIC stack if missing.
I'm also changing the Bootloader to use optiboot and win 1.5K of flash code and setup the Brown Out Detect to 1.8V to be able to works under 2.7V. Please see this Pro-Mini-ICSP-FTDI repo if you need to flash your Arduino Pro Mini with this bootloader. You'll see in bootloader folder, I've compiled some for various Speed and for 8MHz and 16MHz Crystal (I use the 250KBPS one, it's fast and reliable).
Top & bottom side V1.2
Top & bottom side Grove V1.1
You can order PCBs of this board at PCBs.io
PCBs.io give me some reward when you order my designed boards from their site. This is pretty good, because I can use these rewards to create and design new boards and order boards for a discounted price, so if you don't care about PCB manufacturer please use PCBs.io.
Assembled boards with sensors
Bill Of Material
Nothing fancy, all components are 0805 and/or PTH and can be ordered almost anywhere (digikey, mouser, radiospare, ...). use only what you need dependings on what you want to do.
Octopart BOM file
Example of option parts, and other source
- Arduino Pro Mini (just take care your board has A4/A5 at the correct place, some clone are not)
- RFM95 (check Frequency)
- Common Anode RGB Led, search
diffused 5MM RGB LED common anodeon ebay
- Battery Connector format
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
If you want to do commercial stuff with this project, please contact CH2i company so we can organize an simple agreement.