Update: Display TTN-Gateway status

After migrating my TTN gateway to the new The Things Stack Community Edition (see previous blog post) my script to display the gateway status stopped working. The reason behind was, that the new stack does not provide the noc api which was used in the script.

After searching in the TTN forum I found the thread New API for gateway mapping, status and info. Using this API I just need to change one line in my script and now it works again.

-  cmd = "curl -s http://noc.thethingsnetwork.org:8085/api/v2/gateways/eui-b827ebfffe06902a | jq -r '.timestamp'"

+  cmd = "curl -s https://mapper.packetbroker.net/api/v2/gateways/netID=000013,tenantID=ttn,id=eui-b827ebfffe06902a | jq -r '.updatedAt'"

The updated script is available in the github repo.

Migrate TTN-Gateway to The Things Stack Community Edition (aka V3)

 I just migrate my TTN-gateway to the new The Things Stack Community Edition (aka V3). 

I followed the instructions I found in the thread on GitHub.

1. Create a new gateway on the things network (link)
2. Change the server url in your local_conf.json to eu1.cloud.thethings.network
3. Restart the gateway

Unfortunately the new stack does not provide a NOC api - so my script to output the gateway status to a OLED stop working. I will invest into this next.

TTN-Gateway in a box

During the last days I worked on the installation of my TTN-Gateway into a case. This is the result:

Beside the LoraWAN hardware I have installed an OLED display and 3 sensors (1x Si7021, 2x DS18B20). The OLED display is connected via I2C, the sensors via 1-wire and I2C.

The sensor data is read by Python3 Script and published with MQTT. The OLED is also controlled by a Python3 script. Both scripts run as systemd-service.

The software is available on github.

Raspi + RAK831 + converter board - make standard i2c bus available

The RAK831 converter board connects the standard i2c pins of the Raspi with the RAK831 board (RASPI.PIN3 -> RAK.PIN7, RASPI.PIN5 -> RAK.PIN9) (see picture). The RAK831 documentation states the line(s ?) are used to enable the RFSW1012 (see page 15) but does not uses it as i2c bus. The consequence is that the standard i2c bus cannot be used.

On the other hand when looking how to connect the RAK831 direct with a Raspi (e.g. here) the RAK pins 7 and 9 are not used.

This means the i2c bus can be revitalize by removing the 0R bridges R11 and R6 on the converter board.

Setup TTN Gateway using Raspi3 with RAK831 and converter board

Finally I was able to put my TTN Gateway into operation.

The first attempt a few month ago failed and therefore the project was on hold until now. An article in make 03/2019 gave me the impetus for a new attempt.

My essential setup steps:

1. Put the parts together.
   Caution: Do not power up the RAK831 card without connecting the antenna.
2. Prepare a SDCard with a Raspberry Image - I use "Raspbian Buster with desktop" (Release date: 2019-09-26, Kernel 4.19)
3. Perform a general update
   

   sudo apt-get update && sudo apt-get upgrade

4. Enable SPI using raspi-config
5. Clone the ttn gateway repo
   

   git clone https://github.com/ttn-zh/ic880a-gateway.git

6. Run the setup script
   

   cd ic880a-gateway
   sudo ./install.sh

7. Register the gateway on TTN website

After the restart I check the service status:

pi@ttn-gateway:~ $ systemctl status ttn-gateway
● ttn-gateway.service - The Things Network Gateway
   Loaded: loaded (/lib/systemd/system/ttn-gateway.service; enabled; vendor preset: enabled)
   Active: activating (auto-restart) (Result: exit-code) since Tue 2019-10-08 14:05:42 CEST; 779ms ago
  Process: 346 ExecStart=/opt/ttn-gateway/bin/start.sh (code=exited, status=1/FAILURE)
 Main PID: 346 (code=exited, status=1/FAILURE)

ttn-gw ttn-gateway[346]: INFO: Statusstream data is enabled
ttn-gw ttn-gateway[346]: INFO: Beacon is disabled
ttn-gw ttn-gateway[346]: INFO: Monitor is disabled
ttn-gw ttn-gateway[346]: INFO: Contact email configured to "my email"
ttn-gw ttn-gateway[346]: INFO: Description configured to "ttn-rak831"
ttn-gw ttn-gateway[346]: INFO: Successfully contacted server router.eu.thethings.network
ttn-gw ttn-gateway[346]: INFO: [main] Starting the concentrator
ttn-gw ttn-gateway[346]: ERROR: [main] failed to start the concentrator
ttn-gw systemd[1]: ttn-gateway.service: Main process exited, code=exited, status=1/FAILURE
ttn-gw systemd[1]: ttn-gateway.service: Failed with result 'exit-code'.

Damn - the same problem as at first try! :-(

An issue thread on github list some possible reasons, among other "the wiring might be wrong". You may also interpret it as "other then expected or as default" and this was the key. On another page about the setup I found the crucial clue: The converter board uses a different reset pin (it use pin 17 instead of 25).

After changing the corresponding setting in /opt/ttn-gateway/bin/start.sh

#! /bin/bash

# Reset iC880a PIN
# SX1301_RESET_BCM_PIN=25
SX1301_RESET_BCM_PIN=17
echo "$SX1301_RESET_BCM_PIN"  > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio$SX1301_RESET_BCM_PIN/direction

... it worked as expected. And I see the status "connected" on the TTN console (on TTN website).

To enable the GPS module I have to:

1. Disable the serial login shell but keep the serial interface enabled - via raspi-config - interface setup.
2. add the following lines to /opt/ttn-gateway/bin/local_conf.json
   

   "gps_tty_path": "/dev/ttyS0",
   "fake_gps": false,
   

3. Reboot and check if it works (it may take some minutes to fetch the GPS position)

   pi@ttn-gateway:/opt/ttn-gateway/bin $ sudo tail -f /var/log/syslog | grep -i gps
   Oct  8 17:55:36 ...: INFO: GPS serial port path is configured to "/dev/ttyS0"
   Oct  8 17:57:39 ...: INFO: GPS is enabled
   Oct  8 17:57:39 ...: INFO: Using real GPS if available.
   Oct  8 17:57:39 ...: INFO: [main] TTY port /dev/ttyS0 open for GPS synchronization
   Oct  8 17:57:39 ...: INFO: GPS thread activated.
   Oct  8 17:57:39 ...: WARNING: [gps] GPS out of sync, keeping previous time reference
   Oct  8 17:57:39 ...: WARNING: [gps] GPS out of sync, keeping previous time reference
   Oct  8 17:57:39 ...: WARNING: [gps] GPS out of sync, keeping previous time reference
   Oct  8 17:57:39 ...: WARNING: [gps] GPS out of sync, keeping previous time reference
   Oct  8 17:57:39 ...: ### [GPS] ###
   Oct  8 17:57:39 ...: # Valid gps time reference (age: 0 sec)
   Oct  8 17:57:39 ...: # System GPS coordinates: latitude 50.94322, longitude 7.37443, altitude 272 m
   Oct  8 17:57:39 ...: ### [GPS] ###
   Oct  8 17:57:39 ...: # Valid gps time reference (age: 0 sec)
   Oct  8 17:57:39 ...: # System GPS coordinates: latitude 50.94322, longitude 7.37443, altitude 274 m
   

Used hardware:

Raspi3

The converter board with GPS support

RAK831 module

On the left side: 

top - the TTN antenna

bottom - the GPS module (optional)

Connection of the GPS signal

Update: The wiring of the converter board is available on the RAK website.