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…
I need to test if I can get away with this simple circuit. The only challenge with CH340 is that it’s documentation in English is limited, so it’s a bit difficult to read up on all the pin options. But, I have seen others attempting this so will give it a try. This is CH340…
Updated the W5500 Ethernet schematics. C9 to C15 present a challenge in PCB routing since I am using 0805 packages. They are supposed to be attached close to each AVDD pin which is a challenge. Also I added the L1 ferrite bead to stop 100Mhz signals from crossing over. But, I am still thinking that…
STM32F303 is a M4 clocking at 72Mhz. It has strong ADC’s and build in op amps as well as 3 motor controllers on the larger chips. It is a very interesting MCU for specialised motor controllers, but have so far been priced in the 10++ USD region. Lately I noticed that CB and CC versions…