Ethernet Speeds

10Mbit Ethernet Manchester encoding effectively puts 2 bits in each 100nS bit position so the actual bit rate is 20Mbit1.25 MByte per second, = 0.8uS per byte A basic UDP Ethernet Packet: 8 byte ethernet startup sequence 14 byte MAC header # btyes of data 4 bytes of frame check sequenceThis means for the minimum […]

Read More

HTML

https://skanky.dev/cloud/category/html/raw-html-data-over-the-wire

Read More

UART Asynchronous Comms

UART Asynchronous TX Example Internal bit clock and the TX output pin of a microcontroller transmittingbytes with the port configured as 8N1 :

Read More

Solving CE Test Failures

A few ideas on how to solve CE test failures… PSU Noise? Try powering the circuit from a battery without the PSU and re-test? This can confirm if PSU is the source of noise. Use a DC power line filter, e.g. Murata BNX016-01 etc If PSU is conducting test noise through it Are low voltage […]

Read More

Tranzorb diodes

Useful to catch / block high voltage pulses passing through connections such as power supply outputs, power and signal lines leaving a product, etc. Connect across the line to be protected and ground.

Read More

Compliance Test Companies

Test houses we or our clients have used and have had good experience with in terms of helpfullness in resolving CE issues should they arise. Element Eurofins Hursley

Read More

Tamper detect circuit

Simple battery backed up, switch released detect circuit Circuit is 3.3V powered and has a battery. We want to detect if the tamper switch is ever released, even when the 3.3V power is off, so that when next powered up the fact that the tamper switch got released at any time can be determined.

Read More

Switching Mains Power

Low voltage mains power switches https://www.keene.co.uk/keene-kps1-ac-powerswitch-relay-or-trigger-control-for-iot-arduino-rasberry-pi.html

Read More

Encryption Algorithms

A few notes as we come across them on various encryption algorithms. Please note this isn’t intended to be an exhaustive or detailed list of everything, you should carry out your own research before selecting an encryption algorithm, don’t just blindly rely on comments like these here, they may be wrong or out of date! […]

Read More

Security Libraries

OpenSSL http://www.cryptopp.com/ Libsodium (Recomended by Steve Gibson @ Security Now 2017-09, says its the best he knows of plus its audited)

Read More