Hi! I am currently encountering a problem about the USB Host Shield not detecting my USB device (Joystick). I wonder if it is related to the fact that the supposedly 3.3V pin (GREEN box) became 4V after i soldered it. I'm pretty sure it was 3.3V right before i soldered it since i was fortunately able to check it. Also, the Arduino UNO Pin directly beneath it reads 3.3V if the USB Shield is not attached and changes to 4V when it is attached. Pretty sure the problem is in the USB Shield. I dont know what caused this as i made sure not to short it to anything when soldering (refer to the picture). Any idea why it jumped to 4V?
Hi! Yes, that is intentional as the USB shield couldn't power 5v devices if i dont solder the terminals in those 3 boxes (apparently). Check this link for reference:
After checking resistance via multimeter, apparently, they are connected. But im not sure, maybe they are connected via ground after soldering? This was how they looked like before being soldered
1st Cloud: Actually, that solder was just a mistake on my part, didnt bother removing it as it isnt connected to anything (i believe). Normally, that hole/terminal reads 3.3V too but it also became 4V after solder. Didn't actually considered this to be the problem though, do you think otherwise? I'm quite new to this, sorry
2nd cloud: it doesnt have solder on it though. But i cleaned it with alcohol just to make sure
Also, not sure if this can help but after using multimeter to measure voltage of the 2 terminals labeled 3.3V with respect to ground, the one on the left (Pink) measures 4V and the right (orange) 5V. Unfortunately, i wasnt able to measure them before soldering but it just feels weird that they are labeled 3.3V yet none of them is actually at 3.3V. I dont know what they are for though. And I dont have another USB shield to compare to, sadly.
Somehow, I believe that the 5V and 3.3V are shorted together somehow on the shield.
Make sure that the shield is not touching anything on the Uno when you plug it on top
If you still measure 4V, remove the shield as it may damage the Uno
Sorry, what do you mean "not touching anything on the UNO"? It wont get power unless attached on top of the UNO, though. If it is shorted, is there any way to fix it? Can i just remove all solder and just resolder?
Also, after trying other devices, it seems to be able to detect my keyboard and phone but not my gaming mouse and joystick
With you meter negative lead connected to the GND you should measure 5V in the red square, 3.3V in the green square and 5V in the yellow square.
If not then something is shorted.
If your are reading 4V on the 3.3V pads below the Yellow square, then make sure there is NO solder on those pads. To be sure, cut between them with a knife and clean.
The pad on the left should be 3.3V and the one one the right should be 5V. neither should be 4V.
Hi! Thank you so much for this. I checked it out and dug deeper into it. I then found several other posts with similar problem and very similar situation as how i described it here (e.g. only keyboard is detected, 3.3V jumped to 4V after soldering the pads, etc.). I think the problem really lies in the IC used for AHC which is 74HC125 instead of 74AHC125. I will have to buy a replacement chip or find a new shield board with the correct chip used, depending on which will be cheaper in the long run.
The 74AHC125 has over voltage tolerant inputs so can be used for 5V > 3.3V logic level conversion. On this board it is used to convert 5V signals from the Uno to 3.3V for the MAX3421E.
But I would buy a new board from a different seller and hope it has the correct chip. I have never tried SMD soldering or removal.
Unfortunately, my only source for this shield is China and i have asked the sellers what IC they used. They all use 74HC125, sadly. So i have no choice but to replace the chip if i want my project to continue. I have no experience in SMD soldering as well, but still ordered a heat gun so i can practice. This may be a good learning opportunity for me also. Wish me luck!
