I make and sometimes sell USB scopes.
Just to make my life difficult the faster processors and A2D's only come in SMD.
So I solder them by hand. Tack down one corner, check its still straight, tack down other corner, check again. Then slide soldering along the sides until all pins are soldered. Of course some pins short so I have to use braid to unshort them. I always have a row of via's down each side of the SMD's so I can check for shorts between adjacent pins.
This technique generally works after a couple of shorts need fixing.
Built one up today and on screen the output of the scope was only showing half the sine wave on the bottom of the screen. So obviously a problem somewhere. It usually a pin not quite soldered. So I re-soldered both processor and A2D.
Still not fixed. FFS !
Re-soldered both a couple of times more before thinking there might another problem. The A2D sits on a daughter board with two molex connectors from daughter board to the pcb. I then noticed a pin had been missed soldering.
So soldered it and everything burst into life.
An electronic engineers job is rarely simple and these things are sent to try us despite sometimes chasing out tail for a while.
Then got back into my website design. Its a MVC C# javascript, razor etc etc website. MVC while a very tidy way of programming has some oddities.
I tried to have a drop down list but it needed to remember its state between screen redraws. It seems from comments online about trying to do it is impossible. I tried saving state in a cookie but cookies aren't saved straight away but asynchronously so the state was always one out !
I found in the end the answer was to save it in the database.
My old version of the website was not MVC and was quite happy remembering states between screens, you just did a "post back" of the screen and it worked great.
So been very busy, but must find a real job that pays.....
Just to make my life difficult the faster processors and A2D's only come in SMD.
So I solder them by hand. Tack down one corner, check its still straight, tack down other corner, check again. Then slide soldering along the sides until all pins are soldered. Of course some pins short so I have to use braid to unshort them. I always have a row of via's down each side of the SMD's so I can check for shorts between adjacent pins.
This technique generally works after a couple of shorts need fixing.
Built one up today and on screen the output of the scope was only showing half the sine wave on the bottom of the screen. So obviously a problem somewhere. It usually a pin not quite soldered. So I re-soldered both processor and A2D.
Still not fixed. FFS !
Re-soldered both a couple of times more before thinking there might another problem. The A2D sits on a daughter board with two molex connectors from daughter board to the pcb. I then noticed a pin had been missed soldering.
So soldered it and everything burst into life.
An electronic engineers job is rarely simple and these things are sent to try us despite sometimes chasing out tail for a while.
Then got back into my website design. Its a MVC C# javascript, razor etc etc website. MVC while a very tidy way of programming has some oddities.
I tried to have a drop down list but it needed to remember its state between screen redraws. It seems from comments online about trying to do it is impossible. I tried saving state in a cookie but cookies aren't saved straight away but asynchronously so the state was always one out !
I found in the end the answer was to save it in the database.
My old version of the website was not MVC and was quite happy remembering states between screens, you just did a "post back" of the screen and it worked great.
So been very busy, but must find a real job that pays.....
