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I was trying to connect ADXL345 via SPI interfacing to beaglebone black via a breadboard. The board was purchased a month back and was all good when connected to others like mpu6050.

I suspect the ADXL345 device was faulty, and possibly got shorted when i tried to connect it to the board, but i can't confirm on it. The pic of my ADXL345 if you see, has one of the chips at the bottom right corner above Y is slightly bent, so i suspect it is faulty.

My question:

1) Before connecting an external peripheral, how do i ensure it has no shorts? What apparatus or instruments i use to confirm that?

2) What should be the sequence of connection to beaglebone? Do i connect ground and Vcc at the end? Should i connect them when the board is turned off? Should ground connect before Vcc?

Kindly suggest - i have just ended up damaging a new board.

enter image description here

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    \$\begingroup\$ It's not bent, but it shifted during soldering. If the joints are OK that bit should be fine. On the more general point there's a couple of things you can do: (1) use your DMM to check for shorts between header pins. (2) Plug it into a spare header and run 3V3 and GND to a lab power supply, and check the current it takes. Then, for a wee board like this, I'd just go ahead and try it. \$\endgroup\$ Commented Mar 25, 2020 at 13:14
  • \$\begingroup\$ @BrianDrummond Thanks but when you say lab power supply, can you please name an equipment which i can use? And second, what should be the sequence to connect it to a live powerd ON beagleboard. Can i connect everything, (including Gnd) and at last connect the 3V3? I suspect the connecting sequence also matters if i dont wish to burn my board. Your thoughts? \$\endgroup\$ Commented Mar 25, 2020 at 13:42
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    \$\begingroup\$ A lab power supply has one or several outputs, each with adjustable voltage (adjust to 3V3) and current limiting (adjust to 50 or 100mA). I'm obviously not naming brands, that would make it a shopping question, off topic.Sequence is make all connections with the power OFF, then when you're sure it's right, apply power. \$\endgroup\$ Commented Mar 25, 2020 at 13:49
  • \$\begingroup\$ @BrianDrummond Thanks, so that might have possibly shorted the beaglebone and burnt it. I tried to plug all the connectors of ADXL345 live when the beaglebone was ON. Although i made sure to connect the VIN at the end. Another mistake is, i connected first the beaglebone +3V to 3V3 of ADXL345. I believe now from arrow sign 3V3 is the output voltage of ADXL345 and VIN is the input voltage or supply voltage which powers on the device. (pls correct if i am wrong - i am new to this.) \$\endgroup\$ Commented Mar 25, 2020 at 13:57

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1) Before connecting an external peripheral, how do i ensure it has no shorts? What apparatus or instruments i use to confirm that?

Please don't think about looking for "shorts". There are many ways that any electronic device can be faulty. Most of those faults are not "shorts".

If you really wanted to check for "shorts" then you need to be clearer what you mean - shorts between where and where?

In reality, you cannot test for most faults, before trying to use a module like yours.

2) What should be the sequence of connection to beaglebone? Do i connect ground and Vcc at the end? Should i connect them when the board is turned off? Should ground connect before Vcc?

The answer is your suggestion: "Should i connect them when the board is turned off" Yes, make all connections with all power off. Only after all the connections are made (and you have checked that they are correct) then turn on the power. When making connections with the power off, the order of making the individual connections doesn't matter.

Another mistake is, i connected first the beaglebone +3V to 3V3 of ADXL345. I believe now from arrow sign 3V3 is the output voltage of ADXL345 and VIN is the input voltage or supply voltage which powers on the device.

You need to look at the schematic for that specific breakout module, or read its instructions (or reverse-engineer the schematic yourself). The arrow does suggest it's an output, but it might also be usable as a 3.3 V power input, in some cases, if the "VIN" connection is not used - depending on the design of that board.

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