Author Archives: Andrey Fedorov
RS485 interface providing a noise-resistant connection with the equipment at a distance of up to 1200 meters. The question is how to ensure a secure connection of the microcontroller to the equipment operating on the RS485 interface? When lightning, electronic … Continue reading
In the previous article, I reviewed several Arduino RS485 shields. Some of them are quite expensive, more than 20 USD. In this article, I tested one of Arduino RS485 shields, which costs about 3 USD. I ordered at Aliexpress IO … Continue reading
There are a lot of different cloud services in the Internet working as a storage to accumulate telemetry data from IoT devices. It’s quite comfortable services. You don’t need to spend some time to install a server to collect data … Continue reading
There are a lot of different variants of RS-485 shields for Arduino: https://www.waveshare.com/wiki/RS485_CAN_Shield https://www.tinyosshop.com/arduino-rs232-rs485-shield https://www.dfrobot.com/wiki/index.php/IO_Expansion_Shield_For_Arduino(V5)_(SKU:_DFR0088) https://www.hwhardsoft.de/english/projects/rs485-arduino/ Example of using the shield with Modbus RTU termo sensor. Example, how to work with not expensive Arduino RS485 Shield ordered from Aliexpress.
To test a device management by Modbus RTU commands, we use the circuitry of 4 relays controlled by the STM8S103 controller. (Relay MCU 4-way relay-communication board (RS-485). Manage the relay To turn a relay on/off we will use Modbus “Write Single Coil … Continue reading
There is no direct way how to remove a bunch of records from Cosmos DB. Simple query like DELETE * FROM c where c.IoTHub.ConnectionDeviceId != "VariablSpeedDrivesSimulator_test" doesn’t work. But workaround exists. You should create a stored procedure bulkDeleteSproc: /** * … Continue reading
Modbus RTU (RS485 interface) to Modbus TCP converters from the top producers like Moxa, Advantech, Schneider, ABB and etc. are quite expensive. Of course, the quality and reliability of these industrial devices are really very high. Sometimes the most important parameter … Continue reading