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Saturday, 15 June 2013

The Catches – Microcontroller Embedded I2C Module: My First Encounter with Errata-sheet

When I first started doing design works, there was this particular project that required me to communicate through I2C. It was my virgin experience using Microcontroller with embedded I2C engine– and it did not works well – errors occur intermittently – I spent 2 week checked and rechecked my codes, bus waveforms – start , stop, acknowledge conditions – every single thing that I could think of…

There was so much frustration, finally I told myself that enough is enough and there must be something else going wrong instead of my code – and Google long enough – I found out that there’s something called “Errata sheet”. And true enough – looking for the errata of that silicon revision on manufacturer’s website it showed that there was a bug in the silicon – and it proposed some work-around, plugged the workaround in and everything works accordingly Smile

Lesson learnt –
Before choosing a controller or similar devices – always read the errata (if it has one) for the stuffs that related to you, and newly released devices might be more happening that you would expect!

Monday, 3 June 2013

The Catches: Safety Valve of Electrolytic Capacitor

Whether one believes in luck or not, for me there is no deniable that at times luck play a crucial part in life.

I remember my lucky escape from getting injured dealing with a boost converter with electrolytic capacitor. It was a brand new design – a boost that generate 100V. Something was not right – it could not go up to 100V – so I was having this board vised up ( to see what a “vise” is, go to is  to ease probing on each side – with those cap facing me (bad bad choice).

While I my face was inches away from the board – one of the cap exploded and shooting up hot boiling oily substance right pass me, hitting my cubicle wall about 1 meter way – it turns out that wrong part was installed – it was a 48V part.

It could at best cause some burnt on my not so handsome face – or at worst blinded me… come to think about that – I was simply lucky enough to escape un-injured and extremely thankful. To show you what i meant, i managed to find just a similar end result from wiki ( as shown below:
Lesson learnt – those weak points being built on top of the capacitor can is the “safety valve” – it is designed to open up (“explode”) under overheat – overvoltage condition – never ever face the valve toward you or anybody else.