MQTT stands for Message Queuing Telemetry Transport. It is a lightweight protocol designed for efficiently transporting messages between M2M or IoT devices. It uses a publish-subscribe model where devices publish information to a broker, and any number of clients can subscribe to them. For example, a temperature sensor device in …
With the migration of The Things Network to the version 3 stack, I thought it was an opportune time to upgrade my Raspberry PI / RAK833 gateway from the legacy Semtech packet forwarder to Basic Station. Basic Station LoRaWAN gateway maintainers should be using secured and encrypted connections to the …
The Huawei R4850G2 is a very capable 48V Telecommunications grade power supply available brand-new at cheap surplus prices (normally under $100 USD). Rated at 3000W, it can deliver a considerable 56.1A when powered from a suitable 200-240V rated AC source. The CAN2.0B interface allows for online monitoring and/or adjustment of …
I’ve been wanting to automate my EV (Electric Vehicle) charging. It’s a long story for another day. I had started out with a high level RS485 interface into my EVSE (Electric Vehicle Supply Equipment) and hit some ‘bugs’. A month later, it turned out much easier to fall back to …
Featured here is a breakout board for the Espressif Systems ESP32-WROOM modules incorporating a MCU with WiFi and Bluetooth connectivity. The board is designed to be minimalist and targeted towards battery operated devices. As such, no voltage regulator is included. For those not already familiar with the ESP32, this SoC …
Developing ESP32 code by iteratively downloading code to your target via esptool can become laborious for anything but the smallest of projects. In addition to the UART Bootloader, the ESP32 can also be programmed and debugged via the JTAG interface. Debugging allows single stepping through your code, adding breakpoints and …
The Espressif IoT Development Framework (esp-idf) is the official development platform for the ESP32 and ESP32-S series of SoCs from Fabless Semiconductor designer Espressif Systems. Espresif have developed the IDF eclipse plugin to make the setup and integration of the esp-idf with the eclipse IDE simple and relatively painless. Installation …
Anyone who has used a USB Type-A plug will know the fact that it takes three attempts to successfully insert. The USB Type-C connector sets out to solve this life’s little annoyance. But it doesn’t just stop there, it also offers many other advantages: Reversible plug. No upstream/downstream facing connector. …
For a recent OBD2 (vehicle/fleet data-logging) project running on a Raspberry PI Zero, I needed access to GPS data – both position/speed and time. The Raspberry PI doesn’t include a Real Time Clock (RTC). Upon boot, it doesn’t know what the actual time it is, unless it has access to …
Single Wire CAN (SAE J2411) is commonly used in cost-sensitive Automotive applications where speed and cable length is not as onerous. It is also useful in applications were a traditional CAN differential pair is physically not possible. For example, on Type 2 Mennekes connectors used for Electric Vehicle (EV) charging, the …
The CAN bus (Controller Area Network) was originally designed by Bosch for the automotive market to connect ECUs (Engine/Electronic Control Units) together. Today, this robust communications bus is commonly found, not only in vehicles, but also on the factory floor in automation (e.g. CANOpen) and other applications such as PV solar inverter/battery Energy …
Writing user space C code to talk to CAN devices via the Linux SocketCAN interface is relatively simple and efficient. SocketCAN uses the Berkeley socket API and hence is very similar to communicating with other network socket devices. Below is a simple guide to get you started reading, writing and …
The CAN bus (Controller Area Network) was originally designed by Bosch for the automotive market to connect ECUs (Engine/Electronic Control Units) together. Today, this robust communications bus is commonly found, not only in vehicles, but also on the factory floor in automation (e.g. CANOpen) and other applications such as PV …
Most PV solar regulators are buck (step down) regulators and require the PV panel voltage to be above the battery voltage. This design uses a buck-boost topology and allows the PV solar voltage to be above, below or equal to the battery voltage. For example, you could charge a 48V …
Cheap Lithium Battery “Active Balancer” boards have been turning up on Aliexpress and other eCommerce sites. But there has been some scepticism if they are genuinely active balancing and quite a few conflicting forum posts. Some have even claimed the ‘1R0’ inductors are actually 1 ohm resistors. The more traditional …
Motivation I have had the requirement to back-up small 5V low-powered devices such as a Foscam C1 security camera and a Raspberry PI based LoRaWAN concentrator. Many commonly available 5V Uninterruptible Power Supplies feature a two chip design with a Li-Ion battery charger to charge the back-up battery, and boost …
Designs based on the Texas Instrument’s bq24650 Synchronous Switch-Mode Battery Charge Controller for Solar Power With Maximum Power Point Tracking are commonplace on Aliexpress, ebay and Amazon. Consumers can purchase assembled PCBs, such as the one pictured above, or complete product enclosed in a relatively nice aluminium extruded housing. According …
The Atten ATZ97 / Maynuo M97 Series programmable DC loads has a RS-232 port that can be used for instrument control and acquisition. Rather than using more conventional text based SCPI (Standard Commands for Programmable Instruments) commands, these instruments use Modbus, a protocol designed for PLCs (Programmable Logic Controllers). The …
For far too long, I have been on the search for the ideal way to distribute power for low voltage systems, typically 12V. I have an small assortment of domestic networking gear, small embedded systems, LED desk lamps, battery chargers and USB chargers that operate from a backed-up 12V PV …
For the past couple of years, I have been powering my Sony 55” LCD TV and charging a couple of laptop computers from a 12V solar system. Both the Sony TV and the laptop computers have an input voltage of 19.5VDC. To step up the voltage from the battery, I …
Copyright 2021 • Craig Peacock • Adelaide • Australia