Posted on

JLC PCB Assembly Service – First Time User Review


JLC PCB started an assembly service a while ago and I’ve been hoping to design a PCB to use it at some point. I started designing a PCB a while ago – the schematic went quick and then kind of forgot about it for a few months. The PCB is a 64 channel Data Acquisition Unit meant primarily to measure a large number of thermistors, but can also be used as a general digital I/O board.

Board Details

The board is not too complicated – pretty simple, but I wanted to try out a few different things, as well as making it as easy as possible to make and program. I used some chips with varying packages – QFN, TSSOP, and some 0402 passives. I chose a 4-layer board to keep it easy to design and have dedicated power and ground planes for easy layout. I chose ENIG as the board finish mostly because the gold just looks really good. I also put the A2D logo in the corner of the board in copper (remove the soldermask in this area) and kind of wanted this in gold.

As the design software, I used EasyEDA – not because I wanted to use it but because I didn’t want to spend the time to create all the component libraries in Altium. Its also really well integrated with LCSC (a chinese component supplier) and the JLCPCB order service (they are pretty much the same companies just different names for different divisions I think).

I ordered 10 boards with the following specs:

  • 150mm x 100mm outline
  • 4-Layer
  • 1-oz copper
  • ENIG finish (Electroless Nickel Immersion Gold)
  • Green Soldermask (required for the JLCPCB Assembly Service)


The Good

  1. The price – total was around $170 all shipping and import fees to Canada included
    • $65 for the boards
    • $53 for components and assembly
    • $23 shipping via DHL
    • $28 DHL import charges on arrival
  2. Really nice board finish – silkscreen, soldermask, and ENIG finish looked great!
  3. Boards worked – no shorts, etc.
  4. Assembly quality was great – no issues here 0402s and TSSOP packages were great! (QFNs were out of stock so I had to order those from Digikey and assemble it myself).
  5. The boards came packaged really well. I only have components on 1 side of my board, and they packaged them back to back and wrapped in the pink antistatic bubble wrap.

The Not-so-Good

  1. The sides of the board were a little rough – the panel removal left some material on the edges. Nothing that a bit of sandpaper can’t fix, and I can’t really complain for the price that the boards were.
  2. LCSC didn’t have some components in stock or low in stock, so I had to solder a few components myself after the boards arrived.
  3. There were some parts of the silkscreen that were cut off (the RESET at the top of the board). JLCPCB in the past used to be pretty good at catching things like this. I can’t fault them for this since it was my design mistake and I didn’t catch it.

Overall, for quick-turn prototype boards, I can highly recommend JLCPCB. Just make sure that you’ve designed your board and exported Gerbers properly – they will make exactly what you send them. The integration with LCSC makes it super easy to purchase components when you design it in EasyEDA but would require a litt

Posted on

My Vision for A2D Electronics

After spending 4 months away from Ottawa (and my business) at university, I wanted to figure out where I want A2D Electronics to be in the future.
I have spent a fair bit of time figuring out how to make this less work for me and potential future employees, but I also need some direction on where this business will be going in the future.

A2D Electronics exists to provide electronics at a reasonable and affordable price so that anyone and everyone can start making things. It does not exist to make me money. When this started almost 3 years ago now, I realized that the Ottawa maker community had a need for quick access to parts, and I could do something to help that. It was an idea that filled a need and one that I thought could make me some money.
Don’t get me wrong it does make money, but only enough to cover the projects that I make and post and some extra to reinvest in inventory and pay a little towards university. The most valuable things that this company has given me are first and foremost the connections that I have made, but also a feel for how business works on a small scale.

So where is this going in the future?
I want A2D Electronics to continue serving the community. From here on out, that is the main goal.
Before we take a look at how that will happen – let’s take a look at the current situation first.
The most time consuming tasks are restocking and re-ordering inventory, packing orders, scheduling local pickups, and adding new products. The biggest problem here is that I don’t have much time – between working full time on co-op, managing my own projects, other project, involvements in makerspaces and the Midnight Sun student design team leaves me with very little time. If only I could make myself an army of robot minions…
To continue serving the community, my focus will have to shift from being an order-packing robot to a community servant.
Making those tasks easier, more efficient, and streamlined has been on the back of my mind for the last month or so, and I have come up with several solutions that will be implemented in the near future. However, these changes alone are not enough to better serve the community.
One idea that I would like to flush out is to have ‘vending machines’ for electronic components in Makerspaces around the city. These would be amazing, but how would you keep track of everything and accept payments? Those are the questions that I have been dealing with.

So how does A2D Electronics better serve the community of makers?
By making access to components easier, faster, and more affordable. Doing this will mean flexible pickup times, possibly multiple locations, more products, and increased efficiency.
For the next few months, those items will be my focus.

Written By: Micah Black

Posted on

Series and Parallel Cell Configurations

I do not claim to know everything there is to know about battery packs, but from building my fair share of packs, I am hoping to pass on a bit of knowledge.

In order to build a battery pack, individual cells must be configured in series and parallel configurations to achieve greater capacity and voltage.
Each cell has a certain capacity, voltage, and max current that can be determined from the cell’s datasheet. If a datasheet cannot be found, a general safe rule for 18650 style cells is a 1C (1 times the cell’s capacity) discharge rate.
There are a few basic rules to remember.

Parallel Connections:

Achieved by directly connecting the positive ends together and the negative ends together (+ to +, – to -).
Capacity of the cells are added together to achieve a higher capacity battery.
Voltage of the cells remain the same.
Before connecting all the cells together, be sure that all cells are at the same voltage (within 0.05V). If there is a large voltage difference between the cells, when you connect them in parallel with a wire (0 ohm resistance) then when connected together, the cells will try to balance out the voltage. With a larger voltage difference, the current flowing between the cells to balance them out will be large – and charging li-ion cells quickly will create heat.
Cells connected in parallel act as a single, larger capacity cell.
Another common question with parallel cell connections is if connecting cells with different capacities will be problematic. This in fact is not a problem. When discharging the cells with different capacities in parallel, the cell with higher capacity will discharge at a higher current in order to keep the voltage between the cells the same. If both cells discharged at the same rate, the cell with lower capacity would drop voltage quicker. Since the cells are parallel the voltage on each cell must be the same, so discharging cells at the same rate does not work. Both cells must maintain the same voltage, so the cells must discharge at different rates relative to their capacities.

Series Connections:

Achieved by connecting the positive end of one cell to the negative end of the next (+ of Cell 1 to – of Cell 2).
Capacity of the cells remain the same.
Voltage of the cells is added together.
Before connecting cells in series, it is advised but not necessary to balance the cells. The main drawback to connecting cells in series is that the cells must always be monitored to keep avoid over-discharging or over-charging individual cells.
The cells that are chosen to connect in parallel must ideally have the same capacity, age, and internal resistance (capacity is the most important) so that when charging the pack, the cells do not become unbalanced. When charging the pack, if one cell has a lower capacity than the rest, that cell will reach full charge before the others, but the battery will not be at a full charge voltage yet, so it will keep charging. The cell with a lower capacity will now be overcharged and risk heating up and going into thermal runaway. A similar thing will happen when discharging – the cells with a lower capacity will be discharged to a lower voltage than the rest and could be over-discharged if not properly monitored.
Because of this, it is strongly advised to have a Battery Management System (BMS) that is able to monitor the voltage of the pack and prevent over-discharging or over-charging cells. Higher end BMS systems will also include cell balancing – they will keep all the cells at the same voltage level either by bleeding off the extra energy in the high capacity cells through discharge resistors as heat (passive balancing), or by transferring charge of the high capacity cells to the low capacity cells through transformers or other methods (active balancing). Active balancing is generally the better option, as it does not waste excess energy, but it is more expensive to implement.


A battery with X cells in parallel and Y cells in series is referred to as XPYS.
So a battery with 3 cells in parallel and 2 cells in series is referred to as 3P2S.
This battery has 6 cells in it with 3 in paralled, and 2 of those parallel groups in series. It has 2x the voltage and 3x the capacity of a single cell.



The order of the P and S designations in the battery can mean different things. I have heard differing opinions on about whether this 2S3P battery is the same as a 3P2S battery. Both batteries will contain 6 cells, but the order of how they are connected will differ slightly. A 2S3P battery will have 3 series strings of 2 batteries connected in parallel, while a 3P2S battery will have 2 series sets of 3 cells in parallel. The main difference with the 2S3P battery would be that there is no parallel connection across the first set of 3 cells. Each series string of cells should have its own BMS, as all 6 cells could be at different potentials (voltage). It is advised to go with a large parallel group of cells, and put those large parallel groups in series if possible, unless there are problems implementing such a system. When connecting multiple LiPo batteries in parallel through their power connectors, each individual cell should be monitored, as this is a 2S3P style system. A modular battery pack might also make use of this design so that some cells can be removed, while still maintaining the correct voltage to operate whatever device it is powering. The naming and the advice here are not strict rules, but just some of what I have come across on my extensive battery building journeys.

If interested in more information on lithium batteries, here is a great article.
It leans more towards information on charging and storage safety for LiPo batteries, but has tons of great information.

Posted on

Makerspaces In Ottawa

I have been asked a few times about makerspaces / hackerspaces in Ottawa, so here is a list of the ones I know of.


OttawaU Makerspace

Located at the University of Ottawa, this makerspace has 3D Printers, a Laser Cutter, soldering irons, and many other tools. It is open to the public on Sundays from 11am-5pm. Just show up and use them if they are not in use.


Imagine Space at the Nepean CenterPoint Library

This one has 3D Printers and a few laser cutters that can be booked via the Ottawa Library website. You need to book the equipment in order to use it.


Makerspace North

Has regular meetups on Wednesday nights. See their website for more details.


Hack 613

This group changes locations that they meet. Check out their website for current details.

Posted on

Drivers for Arduino Clones (CH340)

Drivers for the Arduino clones that use the CH340 USB to Serial chip can be found below.



Install the drivers before plugging in the Arduino.

Download the drivers HERE.

Unzip it and run the installer.

Then plug in the Arduino, and it should be recognized. It may take a few minutes though.

You may need to restart the Arduino IDE to be able to select the appropriate COM port.



For OSX (Mac) and Linux, have a look at this excellent page: