One of the challenges with classic RS485 is that we use Master/Slave protocol that introduce a lot of waiting latency. We simply use most of the bandwith waiting. I want to try implementing a timing protocol as illustrated below: This is only an idea at present, but I believe it is doable with a STM32…
A RTOS is at the end of the day only a library intended to assist in making your application, meaning that much of the focus on yX is to be able to adapt to your needs and guarantee portability on source code modules. With yX being able to compile on Linux and Windows this also…
yX kernel focus on linear scheduling, meaning that it will run tasks in a time-controlled loop. It is typically used with two cycles, one running in the main loop and a second running on SysTick. Systick on STM32 works well at 1000 times per second using < 1 % CPU load which gives a rather…
A RTOS (Real-Time Operating System) library consist of several components that most often are compiled or linked into embedded applications as a library. You don’t really need a RTOS in embedded systems as many are happy running things in a loop (also called Round Robin) and timing things themselves. However, as applications get more complex…
A classic RS485 2-wire network consist of a Master and multiple Slaves. The master query each slave ensuring that only one device communicate at the time. This makes it an easy network to implement, but the bandwidth usage is low due to all the waiting time. The second issue is that a device needing to…
The schematics for the main MCU parts. This still uses the ESP-03 for Wifi. I intend to replace that with ESP-12 and ESP-01. The m,ain reason is availability & cost, but also the access to Reset pin that is not available on ESP-03. At right bottom you have a 6 status leds, one for each…
The schematics for the NRF24L01+ breakout boards are not the most interesting. It’s a standard SPI with an interrupt pin and two enable pin’s this time. I am using two different footprints that will support 4 different break out boards available. The classic have a range of 100 meters, while the more advanced claim a…
Not finished yet, but an early draft of my communiaction adapter.
Isolated RS485. I seldom bother with terminator resistor on RS485 because I never have errors due to this below 10 meters. Bias is a different issue as I experience problems without bias resistors on one side even on very short distances. The main difference between RS485 and CAN is that CAN uses arbitration and is depending on better…
This is an isolated CAN-HS interface. ADM3053 offer a all-in-one package that cost a bit, but I decided to try it out. As for cost we are talking about 5.- USD rather than 0,5 USD. A normal transceiver will give some protection while ADM3053 protect against much larger pulses, but it is not unlimited. Your…