LoRa vs LoRaWAN LoRaWAN is the communication protocol and system architecture for the network while LoRa is the physical radio layer enabling the long-range communication link. LoRaWAN is a media access control (MAC)-layer protocol built on top of LoRa. LoRa Alliance developed it for use by mobile network operators who want to use unlicensed spectrum to communicate […]
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Designing for phototransistors
Phototransistor basics Wide band vs narrow band photo diode Wide band components can see a wider range of colours / wavelengths, narrow band is more centered on a specific colour / wavelength Basic typical detect circuits Common-Emitter Amplifier (often used): Common-Collector Amplifier: The current generated in the component when light is detected is very small, but […]
Byte ordering
Modbus is a big-endian protocol. The more significant byte of a 16-bit value is sent before the less significant byte So, for bytes on the bus a UInt16 is sent like this: Bits15:8 | Bits7:0 Converting the modbus 16 bit words UInt32 conversion UInt16[0] | UInt16[1] UInt64 conversion UInt16[0] | UInt16[1] | UInt16[2] | UInt16[3] Float conversion UInt16[0] | UInt16[1] //Converting big endian modbus […]
Capacitors and EMC
Bypass and Decoupling Capacitors Bypass and decoupling capacitors remove noise from power rails as devices switch, reducing the ringing waveform which creates EMC at the ringing waveforms frequency. They also cause ground currents to return back to the bypass capacitor of the device instead of to the ground input point of the PCB, stopping large loop areas beign created. […]
Decoupling capacitors
Excellent video demonstrating why bypass and decoupling capacitors are so important for signal integrity and also EMC compliance – a must watch!: https://www.eevblog.com/2018/05/19/eevblog-1085-bypass-capacitors-visualised/
Thermify Data Furnace
In early 2009 IBEX’s chief tech Adam Pulley invented the concept of a data furnace, a device that could be used to heat peoples homes and businesses on-demand, using the waste heat from computer processing. A novel technology based on the fact that all of the electricity electronic devices consume ends up as heat. Computers […]
Xon/Xoff
Xon/Xoff is a software based flow control method. Its very simple and is designed for ASCII based comms links. When enabled the following 2 bytes/characters are sent by the pother side to disable and enable you transmitting: Xoff = Ctrl-S = 0x13 = You must stop sending data Xon = Ctrl-Q = 0x11 = You can start sending data again When […]
Parallel connected LEDs
Useful articles http://www.ledsmagazine.com/articles/print/volume-6/issue-2/features/led-design-forum-avoiding-thermal-runaway-when-driving-multiple-led-strings-magazine.html
Schottky diode
Advantages Low forward voltage drop. Faster than conventional PN diodes (good for RF applications) Disadvantages High reverse current
.Analog To Digital General
Potential Divider AtoD Inputs See notes here.