HED Project

Life/Tech/Ideas

Category: Tutorials

  • DIY Weekend: resurrecting a dead JBL Go Bluetooth speaker

    DIY Weekend: resurrecting a dead JBL Go Bluetooth speaker

    I had this JBL Go speaker laying around and haven’t touched it since I don’t know when.

    I generally like JBL as the sound quality is amazing and the price is way lower than some super high end brands (like BOSE).

    The only problem with this Bluetooth speaker, and generally with the Bluetooth speakers is that the battery is not easily accessible. This means that when the battery is worn off, then you must replace the whole speaker and buy a new one.

    But, if you want to experiment a little bit and you are not afraid to use a soldering kit, then with less than £10 you can give a new life to your speaker.

    The process is straight forward.

    First you remove the front mesh and reveal the speaker and the screw holes.

    Secondly, you unscrew the screw holes (T6 screwdriver to remove the four 9 mm screws).

    The motherboard is revealed. Unmount the speaker cable.

    The motherboard has only 1 screw. Unscrew it.

    The battery can be seen. It is glued on the case. Inside the battery there is a small “charging circuit” which allows the electricity to pass on the opposite way, from the cable to the battery so it can be charger. Remove the battery cover so this circuit can be revealed. Remove the old battery from it but let all the other cabling as it is.

    Solder 2 cables on the new battery. Red is the positive, Black is the negative.

    Connect the Black with the Negative pole on the charging circuit and the Red with the Positive and check if everything works (you don’t need the speaker to be connected, just press the TURN ON button and the blue led should light on.

    Then solder the cables. (not the best soldering in the world…)

    Start reassembling everything back. Put on the screws, mount the speaker and that’s it! The speaker is alive!

    Disclaimer: Use tape to hide all the naked cables so they won’t touch each other and will not create a short circuit.

    Have in mind, the battery that I used has a way bigger capacity that the previous one but there is a catch. It is thicker and I cannot close the speaker completely. So before buying a new battery make sure that the speaker and the battery fit inside the speaker box.

    The battery I used is a rechargable one for an old NOKIA 3310 phone with 3.6V and 1000mAh (£7.99 from Amazon).

  • Don’t use VLOOKUP

    Don’t use VLOOKUP

    VLOOKUP is probably one of the mostly used Excel functions. It is used when the user needs to find things in a table or a range by row. For example, look up a price of an automotive part by the part number, or find an employee name based on their employee ID.

    Its usage is quite simple: =VLOOKUP(lookup_value, table_array, column_index_number, [range_lookup]).

    • lookup_value is the value you are looking for in the table.
    • table_array is the range of cells that contains the table you are searching.
    • column_index_number is the column number of the value you want to return. The first column is 1, the second column is 2, and so on.
    • range_lookup is a Boolean value that tells Excel whether to do an exact match (TRUE) or an approximate match (FALSE). If you omit this argument, Excel will do an approximate match by default.

    Despite being one of the most used formulas in excel it is not wise to use it in big excel sheets that are required to produce prices, forecasts or do other serious calculations.

    The reason is simple. Referring a column without any other references leads to probles as we will see below.

    At the picture exaples let’s assume that we want to add a column next to column E and expand our table.

    What happens is that the reference still remains the 2nd column of the table which is now zero or might have other values that we would insert.

    The previous VLOOKUP formula matching will give us the below:

    That’s why it is recomended to use a more advanced combination like INDEX MATCH MATCH that it’s reference is tied to the header of the table and not by the column distance from the 1st column of the table we want to match.

    To find how INDEX MATCH MATCH works, alongside with other super userful excel formulas visit this page. It’s an absolute MUST KNOW!

  • Save And Close All Open AutoCAD Drawings

    Save And Close All Open AutoCAD Drawings

    Recently, I found myself having 10-15 AutoCAD drawings open at the same time and wanted to close them all.

    An easy way to do it is with two commands.

    To do so, first you type SAVEALL at AutoCAD’s command line and all the open documents are saved. Secondly, the CLOSEALL command follows that will close all the open drawings.

    But… I wanted something more automated. So I wrote a small script that combines those two commands into one that will automatically save and close all the drawings.

    Here’s the script:

    (defun c:SCALL ()
  (command "SAVEALL")
  (command "CLOSEALL")
  (princ)
)

    That’s all. The file is named SCALL.lsp and the command to run it is also “scall” typed at the command line of AutoCAD.

    If you want to know how to load an AutoLISP script in AutoCAD you can read this small article that teaches you step by step what you should do.