Implementing CAN Bus In Software

Some notes about the bus signals CAN bus needs the terminators fitted to the cabling.  If not the signals you see with a scope on the RX side of the transceiver will be wrong! The CAN bus TX line (pre transceiver) idles high.   The CAN bus RX line (pre transceiver) see's everything you TX too (it needs […]

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Parallel Connecting Capacitors

There are several reasons why you often see capacitors, particularly electrolytics, connected in parallel: EEVblog #742 – Why Electrolytic Capacitors Are Connected In Parallel   

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ESR

ESR = Equivalent Series Resistance Lowering ESR Use lower value capacitors connected in parallel.  This gives you the overall capacitance you want and the overall ESR value works just as for normal resistors wired in parallel. ESR and Heat ESR is resistance so if your capacitor has lots of current flowing in / out / etc  then the […]

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Convert toggle switch on to pulse

This circuit can be used to convert a power on switch to a short pulse, which can be useful for instance where you want a micrcontroller to take over keeping the power on once it has started up, allowing it to cause power off should say the system battery level become too low. Or any […]

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CAN Transceivers

3.3V CAN transceivers 3.3V and 5V CAN transceivers are interoperable because High Speed CAN physical layer uses differential signaling that is the same for a 3.3V and 5V CAN transceiver. In addition both the 3.3V and 5V CAN transceivers have the same wide common mode range accommodating not only the typical signaling but also providing wide margin for ground […]

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USB Diagnostic Tools

Windows USB Diagnostic Tools www.uwe-sieber.de/files/UsbTreeView.zip Unzip it and for 64 bit Windows you simply run USBTreeView.exe in the x64 folder (you don't need to install it). To use on a clients system ask them to go to "File > Save Full Report" and send this report to you.  

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.BLE General

Referred to as: Bluetooth Low Energy BLE Bluetooth Smart Part of the Bluetooth 4.0 specification, but has a different specification to classic Bluetooth (it is a lightweight subset of classic Bluetooth). Bluetooth Low Energy is now the best / simplest interface to include for connectivity to any modern mobile operating system (iOS, Android, Windows phone, etc). […]

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Opto Isolating Fast Signals

Fast opto isolators (like the ACSL6400, HCPL-263L, etc) have a max propagation delay specification of around 100nS. To pass say a UART signal through, it is easy to calculate the affect of the propagation delay on the signals.  Actually for a single direction signal like a UART the propagation delay isn't too much of an issue at all if it is reasonably constant for […]

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Custom Plastic Enclosures

No tooling required plastic enclosure manufacturers Smartbox offer a very viable alternative to machined off the shelf plastic enclosures.  These guys will bend and machine sheet plastic to make fully customized enclosures without the need for any plastic moulds etc.  Using different plastic materials and shaped edges you can end up with a really attractive […]

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