Apart from the reasons outlined in the components section, one main reason we select our components is the availability here in Singapore.
We used to source our components from the local Sim Lim Tower, a retail complex with shops selling electrical components. We also purchase certain parts from the local shop SGBotic, which is a distributor for popular brands like Pololu, Sparkfun, Adafruit etc.
However, purchasing parts locally was getting expensive. We had a limited budget with an increasing number of teams to spend it on. Hence, we looked to overseas suppliers like Taobao and other major distributors like element14 which sold parts (sometimes counterfeit) at cheaper prices.
Now, a major reason we select certain components is based on availability on trusted Taobao suppliers. We usually purchase from YouXin and we also discover components from there.
For example, out of all the multiplexers that are available, we narrow our search down by searching for “multiplexers” on YouXin and sorting by quantity of each part sold. This gives us a good indication of the more popular ICs which would probably be more trusted and reliable, and also better supported with libraries and examples online.
These popular ICs are usually also used in popular breakout boards. For example, the LM2596 buck converter IC is both popular as a COTS breakout board and as an IC. Thus, when we shifted from COTS breakout boards to SMD ICs we also looked at the breakout boards we were using while finding different ICs.
This selection process does not really work for tools. We had purchased bad solder which refused to melt, bad flux which burnt off in an instant and smelt bad, and bad power tools that melts itself due to the bad construction and material choices.
The method of sorting by quantity sold only works within a supplier, and usually only for ICs: e.g., sorting all multiplexers within YouXin. When it comes to tools, apart from checking quantity sold we try to look out for the price as well. While this may seem unintuitive, we look out for more expensive tools since most of the time they are still cheaper than purchasing locally, and looking out for the cheapest tools was always too good to be true.