Category Archives: USB3

ESP8266 Lessons Learned

ESP-01The Trip: As regular readers may know, early in 2016 I worked in Spain on a contract with some great guys to analyse information from ESP8266 chips. Without going into any commercial detail, this is what I brought back from that trip as well as other lessons learned since then.

The scenario: The tests were done on a series of ESP-01 WIFI micro-controllers  in a rural environment, initially with a bank of 40 ESP-01 boards. These were powered by a single 20 amps 3v3 power supply. Yes, a switched supply. The boards were mounted on Vero-board and power applied. No linear regulator to smooth out the crap ( I would normally run 5v switched and a linear 3v3 regulator on-board for each device), lossy tracks on Veroboard, signals interfering with each other..  except it DOES get worse - read on.

The Place: The location we conducted our tests was off-grid, relying on solar power and a generator - and the weather most of the time was cloudy - that meant at regular intervals the remote generator kicked in and when it did a couple or so mains cycles were lost as the set-up there uses a combined inverter/charger. The result of that was that at regular intervals, the router reset.

boardsAside from actual power cuts you don't get much worse than this.  At first when we switched on the boards - which are running a modified version of my home control software which is in turn based on TUANPMs MQTT code with a boatload of stuff added and a lot of tweaking over time, only some of the boards would report back. A quick check of the router revealed that by default it only allocated enough room for 32 connections on DHCP. That was quickly doubled and lo and behold, all the boards logged in by MQTT to the PC (running Node-Red and MQTT and firing off data to a database).

Useful outcomes: Well, any thoughts I may have had concerning reliability completely vaporised this last 2 weeks as day after day our little bunch of 40 boards (not even all from the same supplier as some were blue, some were not) just sat there constantly delivering information. This was soon increased to  a wopping 120 boards without issues.

So if you're just starting up with ESP chips - bear the above in mind before jumping to conclusions about board reliability. The boards used in the test, running as I speak, were the early 512K versions, today I always use ESP-12 boards in my own projects as they have eight times the amount of FLASH which means OTA, big programs (up to 1MB of C code (that's a lot)) and in the case of the "F" version arguably better antennae.

I sometimes hear of people complaining that once programmed, some ESP boards go into a loop at power up - and I've recently had this happen to me TWICE. In each case I had extra bits and pieces attached and was running the board off the FTDI - again in each case, putting proper 5v onto the boards immediately resolved the "problem". FTDIs vary a lot in their output and voltage.  While it is tempting to use them to power the ESP (or indeed the micro-usb connector in some cases, straight off your PCs USB - the time will come when this causes trouble and now you know the answer.


Memory sticks/SD and USB3

Check FlashI was just reading an article in a blog where people were slagging each other off over views about USB3 and the speed of memory sticks when a package arrived for me in the post.  A couple of USB3 32GB memory sticks (tiny ones at that).. and it occurred to me that my laptop has a USB3 socket.

So, off I went to the web and picked up CHECK FLASH for Windows – a freeby.

So – the first thing I did was to grab my favourite, fastest 32GB USB memory stick – a Duracell unit. I ran the test which took several minutes – and what did I get? 19 MB read speeds and 13MB write speeds – no errors. I know it is the fastest one I have as I often back movies up to it and when you’re backing up a 2GB movie – you soon make sure you use the quickest drive.

So bearing in mind that this was the BEST I have – and no way the machine will diminish any results as it is a very fast computer… I then went on to try the little mini-32GB USB drive.

Oh, both of these were formatted as Fat32 incidentally and so both complained that “only” a test of 4GB could be done.

Now, bearing in mind that the USB3 unit wasn’t even a super brand name – or ANY brand name for that matter, it is interesting to note that it easily managed 126GB read speed (i.e. SIX times faster read) and 36MB write (nearly THREE times faster write) – I think from now on I’ll be looking around for USB3 – I’m a convert.

THEN I remembered I had a USB card reader and a pal of mine had sent me some Samsung EVO microUSB chips – I read somewhere that these were the best for Raspberry Pi – so – I gave THAT a go too! Strangely the read speeds averaged 41/mb and the write speeds were only 13.4MB – more or less the same write as the USB 2 stick but over twice the read speed – perhaps my expensive USB3 ANKER adaptor isn’t as good as I thought it was - as the EVOs are definitely the fastest I’ve used on the Pi.

Have you come across much faster USB2 speeds that my simple test? What about USB3?