ATMega328 LoRaWAN Node
| ATMega328 LoRaWAN Node Release status: beta |
|
|---|---|
| Description | A LoRaWAN node based on the ATMega328 and the RFM95 LoRa module. |
| Last Version | 0.4 (2021-01-03) |
| Platform | ATMega328 |
| License | CC BY-SA 4.0 |
The ATMega328 LoRaWAN Node is the successor of the ProMini LoRaWAN Node. As the ProMini version, it is powered by an ATMega328, running at 3.3V and 8Mhz, but instead of using an Arduino ProMini board, it uses a barebones ATMega328. This removes the issues of the ProMini board such as weird pin layout for the I2C pins, the always-on LED, and the power regulator. There have been some additional fixes to the ProMini Node board, such as:
- Reordering the power pins so you can solder in screw connectors as well
- Strain relief holes next to the power pins
- Two mounting holes
- No more voltage measurement for the 3.3V/Vcc bus, as this can be done internally on the ATMega
Parts
Note: Antenna and LoRaWAN module are dependent on the local frequency band used for LoRaWAN. The selected items are meant for 868Mhz, which is the frequency band for Europe
Part |
Partnumber |
Amount |
Source |
Notes |
|---|---|---|---|---|
PCB |
ATMega328 LoRaWAN Node PCB v0.4 |
1 |
- |
|
Microcontroller |
ATMega 328P-PU |
1 |
||
IC socket |
28pin |
1 |
||
Quartz |
8Mhz, HC49U-S |
1 |
||
Resistor |
R4: 10k 0805 |
1 |
||
Capacitors |
C4, C5: 22pF |
2 |
||
C6, C7: 100nF |
2 |
|||
Reset button |
SW1 |
1 |
||
Voltage regulator for >3.3V input |
||||
Voltage Regulator |
U3: 3.3V, LDO, TO-92 -> LP2950-3.3 |
1 |
||
Capacitor |
C2, C3: 4,7µF Elko, >16V |
2 |
||
LoRa Modem section |
||||
Antenna |
868Mhz SMA |
1 |
||
Antenna Connector |
SMA Edge mount |
1 |
||
u.FL surface mount |
To connect an SMA antenna, you will need a matching pigtail |
|||
LoRa Module |
RFM95 868Mhz |
|||
Input voltage measurement |
||||
MOSFET |
Q1: BSS 84 |
1 |
||
Resistors |
R1: 100k 0805 |
1 |
||
R2: 150k 0805 |
1 |
max input voltage for this R2/R3 combination: 16V |
||
R3: 10k 0805 |
1 |
|||
Capacitor |
C1: 100nF |
1 |
||
Connectors |
||||
ISP |
J1: 2x3, 2.54mm |
1 |
2x4 connector is much cheaper than 2x3, but you can simply cut off one section |
|
Pin headers |
P3, P5, P6, P9, P10 |
(many pins) |
Just get one long row, and cut off those you need |
|
Screw terminals (Power In) |
P2 (outer pins): 2 pole, 5.08mm |
1 |
only if using voltage regulator |
|
Misc |
||||
Battery Holder |
2x AA |
AliExpress |
||
Case |
Abzweigdose 75x75 |
Hardware store 1, [https://www.hornbach.de/shop/Spelsberg-Abzweigkasten-SD7-75x75-mm-33290701/6060827/artikel.html?] |
References
License
- Licensed under Creative Commons Attribution-ShareAlike 4.0 Unported License (CC BY-SA 4.0)