TR-595E: 004 FRONT ARRAY PCB

JLCPCB

More than two weeks ago, I uploaded Mr. Douchette’s Gerber PCB files to JLCPCB and set my PCB preference to have 0.8mm thickness and have it finished in Black. Below are some of the configurations I’d tweak. The ones in italics can be changed without affecting the USD2.00 offer:

THE USD2.00 CONFIGURATION TABLE

Base Material	FR4	Aluminum
Layers	1	2	4	6
PCB Dimensions (min)	100mm (w)	100mm (h)
PCB Qty (min)	5
Different Designs	1	2	3	4
Delivery Format	[ Single PCB ]	[ Panel by Customer ]	[ Panel by JLCPCB ]
PCB Thickness (mm)	0.4	0.6	0.8	1.0	1.2	1.6	2.0
PCB Colour	[ Green ]	[ Purple ]	[ Red ]	[ Yellow ]	[ Blue ]	[ White ]	[ Black ]
Remove Order Number	No	Yes	Specify Location

Do take note that once the files are uploaded, they will be checked against any MANUFACTURING CONCERNS and not CIRCUIT DESIGNS.

JLCPCB also prints your ORDER NUMBER onto the board. Although it is not an issue with me, you can actually pay to have it removed. I will leave it alone because it allows me to track my PCBs and a very important tool if that design has design issues. For repeat orders, I just click REORDER from my ORDER HISTORY, and with the correct quantity and further fine-tuning.

JLCPCB’s offers are very attractive and for USD2.00, not only do you get FIVE pieces done in FR4, you get to choose how your board is done. This allows me to prototype my PCB in a cost effective manner.

Since, the board is perfect, JLCPCB started the manufacturing process immediately and so, about a fortnight to three weeks (I lost count) later, they arrived on my doorstep. But I am not going to talk about shipping here.

FRONT ARRAY BOARD ORIENTATION

Using the Gerber files again, I re-created a few layers on the EaglePCB. This time, it is for component orientation. This was because I have some issues with the Gerber text which could potentially overlap the component’s VALUES test. After I had uploaded the files, did I learn about the SMASH command in the EaglePCB software.

Before you start, you need to go through his PARTS_LIST.XLSX file which identifies the components because, for example, LEDs D1 and D9 are not the same although they use the same 0805 footprint. One is amber but the other is of a different colour (as in not Amber). Luckily, since both LEDs uses the same 2.2volts, they are literally interchangeable.

The main issue is that LEDs are polarity sensitive components and will only light up if it is connected in one, correct, direction, like a diode. Trust me on this, align the LEDs correctly otherwise, you will spend more time de-soldering and re-soldering them. This process can actually shorten their Lifespan and you might have to get more LEDs.

There is another easier solution, which is to solder the controlling circuits first, and here are the steps:

THE 555 TIMER CIRCUIT

Start with the 555 timer circuit. Once you have soldered the IC and its supporting resistors and capacitors, you are ready to test it. So connect the circuit with low voltage such as 3volts (2x AA or AAA batteries), 3.7votls (LiPo battery) or power from a USB charger which will give you 5 volts (but please, do not plug in to a PC’s USB ports).

Using a multi-meter, set it to 10 volts DC and test for a ‘pulse’ at pin#3 of the 555 IC. If the needle starts moving, that part of the circuit is fine. You can also do the same with a LED (along with its current limiting resistor) and if it blinks, the 555 IC circuit is done. Repeat the same with the other 555 circuit

THE 4017 DECADE COUNTER CIRCUIT

The 4017 IC is a CMOS (Complementary Metal Oxide Semiconductor) device. In other words, it is great for using with low voltage circuits and also, easily get killed from ESD (Electro Static Discharge). Here are tome precautions I would employ when soldering them:

GROUNDING

One way is to touch your hand with a water pipe which can discharge excess static electricity effectively but do not do that if there are lighting strikes nearby. Because I live in a country with high humidity, I am not even going to wear a grounding wrist strap.

Also, do use a GROUNDED soldering iron when you solder.

TEST THE 4017 OUTPUT

Once you have soldered all the components (with the 4017 last), it is time to power it up again and this time, use the same meter to probe at pins #3, #2, #4 and #7. The needle would again, ‘jump’.

Now your circuit is ready. Turn the board on the other side, which is the component side or top, and solder all the resistors.

SMD LED ORIENTATION

You now have soldered all the components and tested the two ICs and you know that they worked. So, it is now the time to put in the LEDs. All you have to do now is to just lay the SMD LED on top of its appropriate solder pad. After a while, it would blink. Or in the case of the LEDs D17-D28 they would light up. At this point, you know which way the LED points to, and you can start soldering it. Please remember to power off the PCB before you start soldering.

ONE MORE THING…

This is the original Gerber data but imported into EaglePCB. I have hidden some layers while those of interest were assigned black colour. This is to make soldering easier so that I can identify the component and its position. More importantly, their orientation as well since LEDs and ICs needs to be soldered in the right direction. This will be my reference map when soldering the components to the Front Array board. And you will notice that most of the horizontal SMD LEDs have their negative solder pads facing to the left.

TOP LAYER

BOTTOM LAYER

THE VIDEO

20220714: After going through the board board, de-soldering and re-soldering the LEDs, I have got it working. I will explain in more detail about the issue in my Blog. Below is the video for the completed Front Array PCB.