Solderless Breadboard Quality

[devnull]

Probably like many people, I have a collection of solderless breadboards, which I have purchased over the years and have no recollection of when or where I bought them, but I suspect most were cheap Chinese clones and some we good quality, but purchased roughly around the same time.

Because of issues related to noisy / high resistance connections particularly related to intermittent startup / brownouts during enabling of wifi on the esp32, I decided to do some simple tests purely based on resistance and used the longest power rails to do the tests.

I determined that the smaller 12x30 boards with a single red / black power rail that I have, were all the same, due to some manufacturing defects that they all had in common.

I then put a jumper across one end of the power rails, shorting out + and - and then inserted a header at the other end connected to a DMM.

First Board
The 12x30 board power rail length is rougly 75mm long x 2 because of the short at the far end gave a length of 150mm.

The inital resistance measured was 8.5 ohms, 'wiggling' around the short and the header pins gave value from roughly 20 ohms to eventually 0.5 ohms, but this value would change with every insertion.

Second Board
I then performed the same test on a longer board, which I immediatly noticed the reflection from the bright contacts where there was none from the previous board.

The total power rail length of this board was twice the length of the previous board with a total length up and down of 300mm.

The initial resistance was 0.28 ohms, inserting, removing and 'wiggling' around the pins resulted in very little change of maybe 0.02 ohms.

This variation is pretty dramatic and clearly shows that in some cases you really do 'get what you pay for'.

[OutoftheBOTS_]

I got so frustrated with breadboard loose connections causing intermittent problems on data lines that I mainly just make a PCB with my laser cutter now and solder all the components when prototyping.

[OutoftheBOTS_]

Also I found that the cheap Dupont jumper wires are just as bad for poor connections especially once the jumper wire becomes well used.

[kevinkk525]

@devnull could you provide names of these boards or pictures so we know what to avoid and which one to buy?

[cefn]

If you ever need to buy in bulk, I have been buying boards for VGKits for >4 years DHL from N.B. Everest in China. I find them consistently reliable (I believe they manufacture themselves).

When I have been forced occasionally buy from elsewhere (e.g. needing an urgent UK order to be fulfilled) to find the breadboards are horrific.