This series documents a set of experiments to explore LoRa for a telemetry application. Note this is simple multipoint to point LoRa, it does not use LoRaWAN.
The block diagram above shows the information flow between the main elements. Continue reading IoT – exploration of LoRa – part 1
At IoT – exploration of LoRaWAN – part 2 I reported some quality issues with two low cost SAMD21 Arduino Zero like boards, and at Arduino SAMD21 bootloader protection some related discussion.
In view of continuing experience of incorrectly programmed low cost SAMD21 boards, I have decided to re-flash them as a matter of course
Above is one of the culprit boards. Continue reading Arduino SAMD21 bootloader protection II
At IoT – exploration of LoRaWAN – part 2 I reported some quality issues with two low cost SAMD21 Arduino Zero like boards.
In both cases, the bootloader did not work. I did not investigate further but did note that the NVM user row looked like it had been cleared, but just wrote a new bootloader and restored a default user row with protection for the 8192 length bootloader.
Above is one of the culprit boards. Continue reading Arduino SAMD21 bootloader protection
At IoT – exploration of LoRaWAN – part 1 details were given of first steps in a LoRaWAN project.
This article documents some MCU boards used for prototyping solutions.
The Arduino Zero concept was chosen for a modern module supported by the Arduino IDE and with ample memory resources for the LoRaWAN protocol stack and application code and memory requirements.
The boards tested are ‘basic’ Zero boards using the Atmel SAMD21G18 MCU. None of the three boards discussed here had the ‘PRO’ EDBG chip / ‘Programming USB’ port, they had only the ‘Native USB’ port.
Above is the module under test. Continue reading IoT – exploration of LoRaWAN – part 2
This article reviews the Dragino LG02 LoRa ‘gateway’.
Above is a pic of the supplied device, and notably it is supplied without the external WiFi antenna shown in the manufacturer’s literature and seller’s web shop.
Above is a close up of the case with the plastic plug removed from the ANT-3 hole, there is not connector, the device does not have provision to install the external WiFi antenna and presumably has an internal antenna though we might expect that has reduced range. Continue reading Dragino LG02 review
This article documents a project with the Espressif ESP8266.
This project is based on ESP8266 IoT DHT22 temperature and humidity – evolution 3, but uses the Bosch BME280 temperature, humidity and pressure sensor. The BME280 has been around for a couple of years, but recently, modules using the chip have become available on eBay for a couple of dollars.
The objective is a module that will take periodic temperature, humidity atmospheric pressure (barometer) measurements, and in this evolution publish them using a RESTful API.
The example platform used in this article is a Wemos D1Pro. In this case, the D1Pro is configured for an external antenna, and a modification is made to the board to add a 1N34A diode for the deep sleep reset circuit (NodeMCU devkit V1 deep sleep). A right angle header on the top of the board (as seen) and another on the underside on the opposite edge to get GND, +3.3, D3 and D4 for the BME280 sensor. There is less than $25 in parts in the pic above. Continue reading ESP8266 IoT BME280 temperature, humidity and pressure
Several of my IoT projects use WiFi, and its range is quite limited, too short to be practical for some projects.
There are several alternatives, but the emerging LoRaWAN concept looks interesting and is worth a visit. LoRaWAN is capable of up to 20km range under ideal conditions, km range should be reliable in most cases.
The first trial is to adapt an existing project functional requirement to LoRaWAN connectivity.
Above is a block diagram of the working trial. Continue reading IoT – exploration of LoRaWAN – part 1
It has become clear that ACMA intends to progress the WIA’s initial actions to partially integrate the qualifications requirement for issue of an amateur radio licence into the Australian Qualifications Framework (AQF).
The AQF is the national policy for regulated qualifications in Australian education and training. It incorporates the qualifications from each education and training sector into a single comprehensive national qualifications framework. The AQF was introduced in 1995 to underpin the national system of qualifications in Australia encompassing higher education, vocational education and training and schools.
That push on integration includes the use of Registered Training Organisations (RTO) for assessments, RTOs are an element of the Vocational Education and Training Sector (VETS).
The definition of Vocational Education and Training can be taken from australia.gov.au:
Vocational education and training
Designed to deliver workplace-specific skills and knowledge, vocational education and training (VET) covers a wide range of careers and industries, including trade and office work, retail, hospitality and technology.
So, the WIA and ACMA have over a couple of decades acted to integrate amateur radio qualifications in the AQF to some extent, and current actions are intended to perform assessments within the VETS (ie by VETS qualified assessors under an RTO). Continue reading Australian amateur radio licensing reform (2018)
The 4-20mA loop used for the water sensor needs a source of 24VDC. This is obtained from the battery (3.6-4.3V) using a DC-DC boost converter which runs only when a measurement is made.
This article discusses related issues. Continue reading IoT water tank telemetry project – part 4
The project continues, albeit slowly.
Some inexpensive DC-DC boost converters have been very slow from China, though multiply source, they have not yet arrived.
An older module which was on hand has enabled progress of reliability and battery trials.
Above is the current prototype. The module on the white plug in cable is a 4-20mA simulator set to 20mA for maximum drain during battery trials. The module at upper right of the pic is a TP4056 batter charger and 1S protection board for the 2000mAh LiPo. The PV array (partially obscured) is capable of 80mA of charge current in full sunlight. The prototype includes a red LED drawing 1mA, an additional 24mAh load per day. Continue reading IoT water tank telemetry project – part 3