Author: Jan

32 x Servo hat

This Hat takes advantage of the many pins on a LQPF64 to output a 32 channel servo Hat. 32 channels is a bit of an overkill for most, but the channels can be used for output, digital input and some for analogue input as well. A separate PSU connector for the servo’s must be provided.…

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Small DC Motor Hat

This is the first draft on a small DC motor Hat. It allows 4 motors to be connected at present. I actually want more motors, so I have to find a smaller connector. I have sufficient space for 8 motors, but the connectors limit me. The challenge is that these 5,08 pitch screw connectors are…

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5xCom 1.2

Not that much to write home about, but this is the latest 5 port communication Hat.  Simplified CAN driver. Added double mounting holes for terminals to enable both vertical and horizontal terminals 3P 2.54 and 2P 5.08. Adjusted drilling hole sizes to M2.5, the same as RPI. Adjusted positions more accurate. Increased GPIO header holes…

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Miniature BLDC Motor Controller

The BLDC Motor Controller above is 40 mm x 12 mm and runs a 3-Phase motor with/without hall sensors up to 2A on 8-16V input. The communication interface is RS485. STM32F030F4 or STM32F042F6 MCU DRV10983 Motor Driver with HEXFET’s. F030/F042 in TSSOP20 package is among the smallest MCU’s from ST. I literally used every pin…

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RS485 Timing Protocol

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…

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RTOS part 3 – CLI

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…

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RTOS, part 2

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…

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RTOS, part 1

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…

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RS485 Timing Protocol

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…

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