This is a digital light sensor. Works with I2C. Obviously the actual light sensor unit is the U1 component visible at the bottom. Then there's a huge crowtail connector on the same side of the PCB. I'd prefer it to be on the opposite side. The same design is seen on the Arduino sensor kit.
I get that it's fun to experiment with the kit and have it all very handy, when the kit lies on your desktop and you test stuff and ideas. But these components could be used in final products, and that's when they appear to be very bad designed. You want to place the main component in a certain position in your device. But the cable connection gets in the way. You want the light sensor to detect light from all around, but the crowtail connector and the connected 4 wire cable shades some light. You want to snap off the OLED display from the sensor kit (it's designed to be snappable, isn't it?) and attach it to a smooth dashboard, but the connector gets in the way.
Is the only reason that I'm only supposed to use these components in prototyping and evaluating, and after that I'm supposed to buy the same components unsoldered to a PCB?
Hobby electronics rides on the back of commercial electronics, and makers of the so called breakout boards use what is available. It costs more to have components soldered on both sides of the board which is why by and large they don't do it.
And is either very expensive or free depending if the sales rep thinks you are going to order a large number of these chips. In contrast to the hobby breakout or development boards they are very large with little on them, and only a data sheet for company.
I still have a few left from my time in industry, mainly from the skip when developers on other projects were finished with them.
If you look at other companies components, there are boards with lower profile connectors, and boards with holes to solder headers/wires onto. The particular boards pictured in your post were designed for educational and prototyping use, likely with a consideration of making the connectors easier for younger people to use.
I asked an eBay vendor if he could sell me bare boards, no connectors, let me orient them my way. no problem. I wish they had a bare board selection as a standard thing
That particular board, the red one, is discontinued. So I ordered its improved succeeder. And I got it without the connector. Only unsoldered male headers. Great!
And the same provider had a Leonardo. Also without headers. Great again.
You can also desolder the connector and put something different on the board, on the back if you wish, or a right-angle connector. Takes very little time, probably much less time than it took to post this, then monitor the feedback. Just sayin'!
I agree, the plastic that the JST type connectors use does not lend itself to the longer heat time required to free a component.
Unless you have decent solder suckers and a good iron, the connectors will come off, but usually not in original condition.
But if you have the hardware to replace the old connector, then go ahead.
It does take practice, but then I've been changing connectors/repairing boards/harvesting parts for 30+ years. A solder sucker and wick for cleanup is necessary. In most circumstances, thru-hole connectors can be removed, as long as you sacrifice the connector and remove the pins individually. Two pin, and sometimes three-pin can be removed by heating all three pins simultaneously(trick - large solder blob on iron tip applied across pins), but beyond that sacrifice is the best route. Surface mount? I don't have the skill, but I would think it's easier, because you don't have the mechanical bind of the pins in the holes; the downside is, pads don't have the through-hole mechanical support, so are more likely to de-laminate. I was given a hot-air de-soldering tool but haven't used it, I may try it next time.
Be aware that things like the optical sensor in the first photograph of this thread, will not work if you simply solder them to the back of the board, because the pinout will be back to front, so you are faced with the task of cutting all the tracks leading to this chip, and rewiring them with thin "mod" wire.
Being dyslexic it is something that has caught me out serval times. There are ways round it like using the ridicules expensive through hole funnels, and soldering onto the back.
