LED Grow Light Station for Chilis and Tomatos

Days are getting longer, and in the afternoons the temperature rises above 10¬įC… but if I’ve learned a lesson the last two years then that growing chilis and tomatos in our living room (although located on the south side of our house) is still far from enough for these seedlings…

So I’ve taken a few hours and built an LED grow light station for them. ūüėÄ

Two LED panels (bought on Amazon for ~ 23 ‚ā¨ each, hanging above two tubs with seedlings.
These photos show the seedlings two weeks after sowing the tomato and chili seeds.

PONG… I’m online and answering again…

I did not post anything for quite a while… we bought a house and moved into it. This consumed most of my spare time and my ‘hacking capabilities’ during the last few months. But the good news is: I’ve now got a whole room in the cellar which I’m currently turning into a hacker lair / electronics shop without having to care too much about the the WAF.

I just just returned from a business trip to the US and wanted to ‘report back’ with a nightly impression of New York / Manhattan. (Please forgive the low quality as the photo was taken with my smartphone from the airplane window.)

RANT: Do not misuse spreadsheets for data storage

Using spreadsheet files for data storage and exchange can lead to the
corruption and even loss of information — sometimes without noticing it immediately. I came across this one too often so¬†I could not help but¬†write a¬†rather long post about this topic.

Sharing datasets with other researchers or collaboration partners is a vital part of the knowledge exchange in a community. This might happen in big scale in form of supplementary material along with publications or in small scale within research groups. In this post I do not want to focus on what is actually shared, but how. Because a crucial but commonly underestimated element when sharing datasets with others is the used data format. Continue reading

Aliexpress search customization and optimization (via hidden sort options in the URL)

About a year ago¬†(2016) Aliexpress decided to cripple simplify their search engine. They’ve removed really useful search options and added (at least in my eyes) unnecessary ones.

These useful search options were removed from the search panel but they are still available as URL parameters. I’ve mainly written this post to document these missing options for my everyday searches¬†— but¬†I’m pretty sure others may find them useful as well.

Aliexpress Hidden Search Options
Parameter Declaration Description
isUnitPrice y Show Price per Piece
minQuantity value Minimal Quantity in Lot
maxQuantity value Maximal Quantity in Lot
minPrice value (e.g. 1.23) Minimum Price
maxPrice value (e.g. 9.87) Maximum Price
isFavorite y Results with 4+ Rating
isFreeShip y Free Shipping only
sortType price_asc/price_desc Ascending/Descending Prices
shipCountry de/us/… Destination Country
shipFromCountry cn/de/us/… Country of Origin

Especially the option isUnitPrice is helpful when searching for the best price per piece and not price per lot. I really cannot understand why this option is not available per default.

So when I’m searching for the lowest price per piece within a certain quantity range (here: 10 – 50 pieces) with free shipping I would add to the URL (Example Search):

&minQuantity=10&maxQuantity=50&isUnitPrice=y&sortType=price_asc&isFreeShip=y

Side Note: It also makes a difference which keywords you are using when searching. The following three searches will (at least the last time I’ve checked) give different results:

  • “stm32f103c8t6 lqfp
  • “stm32f103c8t6 lqfp48
  • “stm32f103c8t6 lqfp-48

So even slight variations can make a big difference. Unlike the search on eBay, the search on Alibaba and Aliexpress does not split up keywords into smaller ‘chunks’ which are used for searching.

2018-08-02: Updated the List of Search Options

Started to build my Raspberry Pi PiDrive System (for RetroPie)

I’ve started to rework my Raspberry Pi ‘dial-up’ interface. Instead of just handling my external VPN and SSH connections¬†I’ve extended it to also function as an intermediate file server and Git repository (both via NFS+SSH). I’ve also inserted the Raspberry Pi into a new case and added a 1 TB 2,5″ drive. I think it¬†can handle additional load so I plan to extend its capabilities to also serve as a RetroPie console.

By the way: the case and the connector cable between the drive and the Pi are both from WD Labs. The hard drive is not a PiDrive but a refurbished USB 3.0 1 TB disk¬†(it was a recertified My Passport Ultra) before I’ve dismantled¬†it. For me it was cheaper that way. If you’re looking for a similar setup and need an additional power supply and SD card maybe you should think about buying a Nextcloud Box¬†(free shipping;¬†handled by WD). You might¬†not need to use its ‘cloud’ functionality but still get all hardware I’ve previously mentioned which I think is a¬†pretty good bargain.