{"id":2451,"date":"2022-05-08T11:21:28","date_gmt":"2022-05-08T09:21:28","guid":{"rendered":"https:\/\/www.nico-maas.de\/?p=2451"},"modified":"2022-05-08T11:21:33","modified_gmt":"2022-05-08T09:21:33","slug":"taming-the-rak5146-sx1303","status":"publish","type":"post","link":"https:\/\/www.nico-maas.de\/?p=2451","title":{"rendered":"Taming the RAK5146 \/ SX1303"},"content":{"rendered":"\n

Its been a while - but good things come to those who wait ;).<\/p>\n\n\n\n

Trying to work out a new system you're unfamiliar with can be quite a challenge. In my case I got my first LoRaWAN concentrator along with some CubeCell HTCC-AB01\u00a0and tried to get them to work. It turned out - it was quite hit and miss. On the one hand, the firmware support for the RAK5146 with USB, GPS and LBT was not really ready yet - on the other hand, the CubeCell Arduino code has a fatal flaw<\/a> with the preamble size so that those cannot join a LoRa network if used in EU868 MHz Band (the perfect fix<\/a> by 1rabbit is linked as well!).<\/p>\n\n\n\n

In the end, as I wanted to get this working as best as possible, I bought myself the RAK2287 Pi Hat<\/a> and started modifying it. I was quite sure that the I2C signals should be available somewhere on that board - as well as 5V + 3v3 along with the raw PPS signal of the GPS module within the RAK5146. I was right and could bridge the PPS signal to an used RPi GPIO pin. <\/p>\n\n\n

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PPS Pin bridged to GPIO 04<\/figcaption><\/figure>\n<\/div>\n\n\n

Using the I2C signal lines, Ground and 3v3 I added an I2C sensor interface (call it an ugly QWIIC connector ;)).<\/p>\n\n\n

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PPS hack and \"poor mans QWIIC connector added\"<\/figcaption><\/figure>\n<\/div>\n\n\n

I installed the latest UDP Packet Forwarder <\/a>package by Xose - and everything was working perfectly since then.<\/p>\n\n\n\n

I even added brocaars Packet Multiplexer<\/a> and started running a local ChirpStack instance on my home server. Now my sensors are feeding their data directly to my local InfluxDBv2 and Grafana - but at the same time my Gateway is still available for TTNv3 users to receive their data. Its awesome and with that I even receive my private data during WAN outages. Nice!<\/p>\n\n\n\n

As added \"bonus\", my gpsTime<\/a> project is running on the same RPi, using the GPS time of the RAK5146 and its PPS signal to be an extremely precise GPS timeserver in my network - and an additional BME280 is running as the \"room sensor\", because adding another battery operated device - if you are having more than enough CPU power (in form of the RPi ;)) is really not needed. The whole device fits behind the TV.<\/p>\n\n\n

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\"Not Great, Not Terrible\"<\/figcaption><\/figure>\n<\/div>\n\n\n

All in all, the project was very successful, I am working on some new ideas regarding the sensors, but this is pending on my KiCad 6 skills and deliveries of new RAK hardware currently on the way ;).<\/p>\n\n\n\n

I still keep all infos in the balena Forums<\/a>, so head over if you want more details.<\/p>\n