Smart SPI is a Layer 1 – 2 protocol using SPI to establish a direct communication link between Raspberry PI and Hat’s. SPI itself is a bit oriented full duplex protocol where the master control the speed by ticking a CLK signal. For every cycle on the clock we transfer a bit on both MOSI…
I initally hoped to test rev 1.0 of this Controller back in february, but as often happens with hobby plans – they get delayed because of real life. I am still waiting for the PCB’s on 1.0, but I am already starting the planning for rev 1.1. Testing the design on 11.1V battery. Testing power…
Final 3D model with TVS diodes added. This is not the most Advanced Hat, but it enables me to use a Raspberry PI With long wiring and motors in the network without too much worries.
I used a little trick on the 3-port Galvanic RSX as I connect to ground through the ground layer on layer 0. If you look at the area marked in green this is part of the ground, but the EDA don’t warn me that this is an iceland isolated from actual ground. I added a…
I made a 5 port (3 port RS485 and 2 port CAN) earlier that is great, but I want a version that is galvanic isolated for solutions that require wiring around a house or more hash environments. ADM2582E is a “All-In-One” package for this, so using 3 of these I get a 3-port RS485 will…
This diagram illustrate my Home Automation Centre. The idea is to use isolated RS485 networks – no power – to control actuators and sensors. Power will be entered by through RS-X adapters I will draft later. I am a bit undecided on Ethernet/Wifi as this also can be sorted through Raspberry PI. The one thing…
Finally got the shunt resistors (red) and had to increase the width of the board due to their size. I have ordered the PCB’s so we should have them in ca 6 weeks time.
This is the schematics for the regulator side of the Lab PSU. I am using the classic LM723 in this design which allow for current and voltage adjustments through potentiometers. T1 & T2 deliver a max of 15A each, but current will be limited by the shunt resistors R14 & R7 as well as R9…
Reviewing the design for a home automation system I realise that a PLC rack is not optional as a control system centre. The reason is that we will mainly be interested in central node processing and communication – we will not be interested in more classic PLC controls. Also we need these centrals to be…
As we log output voltage, current as well as few other things it would be nice to be able to display a real-time oscilloscope alike picture of these. This functionality is only available on PSU’s far more expensive, but is easy to achieve thanks to the Nextion displays. The illustration below is a draft of…