This build is heavily based on ttn_zn's build, but we're extending it to be standardised for several deployments, IP67 rated, with some access hardening, NAT punching and remote logging.
Deployment is controlled via ansible, instructions are in the deployment directory.
TODO: Build instructions are not yet available
For the sensor, case and power supply:
|LoRaWAN concentrator board||£200||ic880a (IMST Webshop)|
|UF.L (IPAX) to N-type pigtail lead||£7||Solwise PIG-IPAXNCHSSKT25|
|RPi to iC880a interface||£7||supplied from;|
|Raspberry Pi 2||£32||RPi2:|
|MicroSD Card (8Gb+)||£7||A Sandisk Extreme/Ultra in 8Gb or 16Gb is preferred (based on usage bias) Amazon|
|up to 32V input down to to 5V output DC-DC voltage converter||£11||Pololu 5V 5A Step-Down Voltage Regulator D24V50F5 (hobbytronics)|
|2.1mm DC socket to micro-B USB plug||£1||(Amazon)|
|IP68 Ethernet DC splitter||£5||(Aerial.net)|
|IP 67 rated enclosure with Ethernet and N-type holes, wall and pole mounting kit||£20 (plus £20 p&p)||EZNET EZ-SOE01W (Aerial.net)|
|LMR200/HDF200 co-axial cable||£1/meter||Solwise HDF200|
|N-type Plug for LMR200/HDF200 cable (50ohm) ×2||£3.10||Solwise N-Type 200 Plug|
|N-Type plug/jack inline coaxial surge arrestor||£31||Diamond SP-3000P|
|Ethernet Network surge arrestor||£20|
- The IP67 rated case that we're using has N-type connector holes, so we're standardising on N-type connectors for the antenna lead.
- There are two types of N-type connectors, 75Ω and 50Ω. They are not directly compatible, despite appearing superficially similar. This project uses only 50Ω connectors.
- This build uses LMR200 or equivalent coaxial cable for the antenna; this is a very similar diameter to RG58. The larger diameter LMR400 would also be suitable (and would require alternative N-type connectors), this would provide a much lower resistance (0.1Ω/m vs 0.3Ω/m) and longer range.
- Regardless of the cable diameter, is recommended that the the coaxial length is kept to the minimum, ideally less than 1.5m.
For the Raspberry Pi, interface board and concentrator board:
|M2.5×8 nylon set screw||6||Farnell 2472704|
|M2.5 nylon nut||6||Farnell 2472686|
|Brass spacer 4.5×3mm||4||Farnell 1466898|
|Brass Jack screw (male-female standoff) M2.5×11||4||Farnell 2494583|
For the Pololu DC-DC converter:
|M2x5 nylon set screw||4||Farnell 2528936|
|M2×10 standoff (female-female)||2||Farnell 2494574|
To reduce the cabling and case openings in the IP67 case, the raspberry pi is supplied with power using Power over Ethernet (PoE). The chosen Pololu DC-DC converter can step down voltages up to 32V, but PoE supplied at 12V or 24V will be sufficient.
|A 12V supply with a 2.1mm DC plug OR a proper POE injector|
|Cat5E or Cat6 Ethernet cable (for external use)|
|8P8C (aka RJ45) connectors|
Antenna option 1
Quarter wave ground plane:
|¼ wave ground plane omnidirectional antenna||£45||Aurel GP868 (Conrad Electronic)|
|BNC jack to N-type plug adaptor||£5||TE Connectivity 1-1337567-0 (Farnell)|
- This antenna is has an F-type jack and is supplied with 2.5m RG58 cable which is terminated in a BNC plug. The BNC jack to N-type plug adaptor allows connection to the N-type pigtail in the case.
Antenna option 2
Half wave dipole:
|Barracuda 5dbi omnidirectional antenna||£90||Digikey 931-1255-ND Taoglas OMB.8912.05F21|
|N-type coax connector crimping tool for LMR200/RG58||£24|
|RG58/LMR200/HDF200 coaxial stripping tool||£12||332D Stripping tool (Solwise)|
The following parts are not required for the build, but might be useful for on-the-bench testing. No more than one of each is needed:
|UF.L to SMA pigtail lead for test antenna||EUR 6.5 (excl. tax)||IMST Webshop|
|SMA ¼ wavelength Test Antenna||£5–£10|
|RPi Power Supply 2A with micro USB||£9||Farnell|