Arduino MEGA Sensor Shield v2.0, Missing Connection and Shorting Problem

Using Arduino General Electronics
#1

If you get an “Arduino MEGA Sensor Shield v2.0” board in a Starter Kit from China, be aware that there might be a missing connection (either that or my board doesn’t have proper plated-through holes and a connection on the other side of the board on that line).

The board is designed so that there is a GND line on the top of every signal pin in the center and a 5V line on the middle of every signal pin connector. Then, the bottom row is the signal pin.

However, at least on my board, between signal 35 and 36 on the V (5 Volt) row, there is NO CONNECTION. This means that the logic of having 5V on the middle pin is lost for signal pins 36 - 45 and the middle V pin will float.

The solution is simple, I took a teeny piece of wire and soldered it on the bottom of the board between pins 35 and 36 on the V row. Ta-dah.

Second, big, problem (that is well documented on the internet) is the 'USB Connector Shield shorts-out with one pin of the 2 pin PWR_SEL jumper. Ouch and dangerous. The first time I plugged the board in I got no LED and wondered what was happening. I was holding the board and felt intense heat. It was shorting the power supply completely.

It is easily rectified, however. Just snip off both of the PWR_SEL pins as close to the board as possible and sand down the pin closest to the edge with a Dremel tool and 2-seconds of contact or sandpaper used gingerly.

Then place a square of good-quality (3M Temflex 1700C, or equivalent) electrical tape, carefully cut and wrapped snugly around the USB connector. Then place a tiny 1/4" x 1/4" tape on the circuit board over that pin.

I believe that that board is now up to version 2.4; so they probably got rid of those problems in the newer version boards (hopefully); but for those who are still getting Starter kits from China, their old stock will probably last quite some time.

I suspect that many different manufacturers (Bangood, SainSmart, Mausan, HiLetGo, etc.) are all copying each other on this board; so most probably don’t exhibit these problems. It should be pretty simple to determine whether you have this board. Just look to see if pin 45 is labeled correctly on the PC Board Silkscreen. If it is labeled 44, you have a board which might exhibit these problems.

Just plug in your Breakout board, and before you plug in either the USB cord or power cord ensure that the pin doesn’t touch the shield. Second, take a continuity reading between pins 35 and 36 on the V line to ensure they join. Since these guys copy each other’s boards… I wouldn’t put it past them to have the same problem exhibit on all v2.0 boards.

Mine is called “Arduino Mega Sensor Shield v2.0” on the silkscreened PCB. Most don’t have the word ‘Arduino’ before MEGA.

Although I have, as yet, never found a data sheet on that exact board… this v1.0 data sheet is pretty good: http://www.emartee.com/product/42016/

Arduino_Mega_Sensor_Shield_v2.0.jpg
Arduino_Mega_Sensor_Shield_v2.0.jpg864×634 205 KB

#2

Whoops... I said the wrong two pins that the lack of a short is between on that post.

Look at the picture and you'll see which two pins I had to short together. It's between Signal line 31

and 32 on the V row, not between 35 and 36.

You could, also, just use a two-pin shorting connector from the front side like is used on any PC board

if you don't mind losing two of the V pins.

#3

Hi, thanks so much for this post.

I know this has been inactive for a while, but I've got a quick question I thought you might be able to help with: I'm using the same sensor shield (says "Arduino MEGA sensor shield v2.0"), and my code has recently begun to malfunction after I unplug the USB cable from my PC.

I'm not sure what "USB Connector Shield shorts-out with one pin of the 2 pin PWR_SEL jumper" means exactly, but I've lifted the board up enough that there isn't anything touching the top of the USB jumper (if that is what it means). Do you think the shorting has anything to do with this?

#4

TheWind777: Whoops... I said the wrong two pins that the lack of a short is between on that post.

Look at the picture and you'll see which two pins I had to short together. It's between Signal line 31

and 32 on the V row, not between 35 and 36.

You could, also, just use a two-pin shorting connector from the front side like is used on any PC board

if you don't mind losing two of the V pins.

Hmm mines was exactly between pins 35 and 36 Thank you for sharing this topic anyway

brightorange: Hi, thanks so much for this post.

I know this has been inactive for a while, but I've got a quick question I thought you might be able to help with: I'm using the same sensor shield (says "Arduino MEGA sensor shield v2.0"), and my code has recently begun to malfunction after I unplug the USB cable from my PC.

I'm not sure what "USB Connector Shield shorts-out with one pin of the 2 pin PWR_SEL jumper" means exactly, but I've lifted the board up enough that there isn't anything touching the top of the USB jumper (if that is what it means). Do you think the shorting has anything to do with this?

Hard to say if mega chip is damaged but I think no. Does this problem repeat without sensor shield? You should use tape over usb chase three times. These pins on the back are still sharp and it drills the tape. Try to cut these pins on the back shorter.

#5

forgoden: Hmm mines was exactly between pins 35 and 36 Thank you for sharing this topic anyway

I have just received an order from Aliexpress; decided to try out this "Sensor Shleld v2.0" ... yes, I am quoting perfectly.

I too have the same V bus not continued through across the whole board @ 35 & 36.

This thread is still relevant to anyone ordering from China on Aliexpress! for AUD$3.55 and shipping shared with other cool boards, worth it, even with needing to solder a bridge in, and insulate the USB-B header from the power selector.

#6