In this post, we’ll see how to make an SD card reader shield for the Arduino. It’s pretty simple as it’s just a matter of connecting the proper Arduino pins to the correct pads on the SD card adapter. Additionally, resistors need to be added for certain pins. These will form voltage dividers that will drop down the signal voltage for the SD card from 5V to around 3.3V.
In this post, I’ll show my DIY SMD vacuum pickup tool. I bought this vacuum pump SMD pickup but it had no way to be turned on/off. There is only a hole on the vacuum “pen” that you can cover with your finger to make or release the vacuum. I decided I would mod it and make it operable with a footswitch. When pressed the vacuum pump is turned on and when you let go the vacuum pump is turned off while the valve is opened at the same time to release the vacuum and instantly drop the SMD part from the nozzle.
In this post, I’ll show my DIY solder paste dispenser. It’s powered by a 12V adapter and can be operated by a footswitch(connected via banana connectors). It uses a small membrane air pump/compressor to dispense the solder paste/flux. Additionally, there is a solenoid air valve connected to the airline so the pressure can be released after you let go of the footswitch which prevents the solder paste or flux from oozing out. The pump and valve timing is controlled through a relay module by an attiny45 microcontroller.
In this post, I’ll show a DIY power supply I made from an old computer PSU. This is a great way to get a fairly powerful lab power supply with a range of different voltages for cheap. I used a breakout board I bought online as it’s much quicker and simpler than drilling holes for all the connectors into the case and then soldering all the wires.
In this post, I’ll show you how I fixed my dead GPU by simply heating it up. Some time ago the GPU in my old computer died(black screen). I managed to repair it by simply slowly heating it up, keeping up the heat for some time and then slowly lowering the temperature back down again. As my previous PC was quite old when this happened I got myself a new one and haven’t used the old PC very much since then. So I don’t know how much longer the fixed GPU might have lasted after that.
In this post, I’ll show a DIY 9V battery portable power supply I made quite a few years ago by originally following this tutorial. This particular power supply uses a voltage regulator(LM317) to drop down the voltage and dissipate the energy as heat. This means it becomes inefficient at higher currents. So it is most useful to power things that don’t require a lot of power.
In this post, we’ll take a look at the inputs and outputs of my 8-bit computer.
In this post, I will talk about the ALU and the flags register of my 8-bit computer. The arithmetical logical unit(ALU) is where all the computation happens in a computer. The ALU of this computer is very simple and only has the option to add or subtract numbers. So something like multiplication would have to be implemented in software. The flags register stores the Carry(a carry occurs) and Is Zero(the result is a zero) flags that it receieves from the ALU.
In this post, we’ll take a look at the button debounce module of my 8-bit computer. Ben used a 555 timer in his clock module to make a delay to debounce the button. I took a different approach. I took the 50 MHz input from the crystal oscillator and lowered the frequency by using another clock module. This way I have another slower clock signal independent from the main clock. This slow frequency is then fed into the debounce modules.
In this post, we’ll take a look at the clock module of my 8-bit computer. Ben used a 555 timer in his clock module to generate the clock signal for his breadboard computer. The approach I took is a bit different. The DE0 Nano FPGA development board has an onboard 50 MHz crystal oscillator connected to one of the pins of the FPGA. This is where we can get our clock signal from. The problem is that the frequency is way too high for the computer and needs to be lowered. This can be accomplished by dividing the frequency using a frequency divider(which is esentially just a ripple-carry counter) or by using a PLL(phase locked loop).