do it yourself electronics

hello. this is the "do it yourself" m12864 graphics version transistor tester kit from banggood.com. i will build it and review it and seehow it works. so let's get started. this device can measure resistors, capacitors, inductors, diodes, transistors, capacitor esr. you cangenerate a pwm signal. it can measure frequency and it has a graphical display. i'm going to start by measuring the resistors and mounting them, and then i'm going to solder them first. i'm measuring them for better accuracy, so if they're not good enough, i'll pick some of my own. i like mounting them left to right. the colour code. i think i'm going to look for another one.

this one will do. found one. i'm just going to do the same for the rest of them. ok. now that i've finished mounting the resistors, i'm going to turn the board around and lay it flat on the desk. i'm going to cut a few of the leads. and you should keep those. you might need them later for some soldering. so, we're done with the resistors. next, i'm going to solder the capacitors. when soldering electrolytic capacitors, you need to check the polarity. be careful not to cut into the soldering so you don't damage it.

also, you should hold on to the leads, so they don't get into your eyes. next step, the transistors. make sure you get the numbers right, also the orientation. next we have the led. which you should also check the polarity of. it has a cut right here. that follows the cut on the board. also, you can judge it by the length of the leads. the positive being the longer one. next, the socket for the microcontroller unit. you should check the little cut here. should be the same on the board.

first going to solder the opposite pins, so it will hold in place while i do the rest. now i can do the others much more easily. i'll put the lcd pin header first. same thing, opposite side pins. for the screen, you start on the 5th pin, up to the vss pin. made a mistake with the lcd, you go from the 5th pin which is leda up to d6 which is the 12th pin. so i had to move one of them. ok, that should do. the last part is the encoder, which is also a push button.

ok, and that's it for soldering. ooops, forgot about the power. so still have a bit of soldering to do. these are the pieces that i have left. the problem is i only got 2 of these metal holders, which are supposed to go here, and support the whole device. but i only got 2 so i'm not going to mount them. other than that, before you put in the microcontroller chip, you should check the voltage that comes from pin 7 and pin 22. so let's do that. have to power the device first. i'm going to use a 9v battery.

so you go to pins 7 and 22, you hold down the button, and it should display 5v. and it does. next, i disconnect the power and plug in the microcontroller. you should follow again the little cut there is here, to there (on the board). and be careful not to bend the pins when you plug it in. well, of course you have to bend them a little, so it does go in. ok, now that that's in, put in the display. and let's power it up.