ESP8266 Tuesday Update

esp-03[7]I noted this item on EBAY showing the ESP-03 at well under £2 each.. Not sure about those ceramic antenna – anyone any experience of how they compare to the excellent PCB version on the ESP-01 ??

Another item of note – I see there is a new LUA update out – looking forward to checking that out at the weekend and I’ll do a write up – apparently it’s based on the 0.9.5 version of the SDK. Is this out of BETA – and if it is does anyone have the link? And any updated documentation so we know what’s changed? I have to say that Espressif don’t do the best job when it comes to promoting their own updates.

That’s it for now – later this week I plan to put together a temperature sensor using only the ESP-01 and even consider sticking a lithium and a solar cell on it (I know, not the best time of the year for solar power) – more to have a permanent test rig than anything else sending out MQTT data.  The /TIME/ message I set to run every 10 seconds on my PC 3 days ago using Really Small Message Broker set up as a service, and MQTT-spy – is still ticking away (I can test it in meetings using another copy of MQTT-spy.   You might have noticed I did some frighteningly fast message blasting and everything help up ok. I expect soon to have MQTT traffic running back and forth – I’ve at least 3 locations that need external solar powered temperature and humidity monitoring.   MQTT-spy is due shortly to get some more improvements – looking forward to it – as for RSMB – I can’t think of anything wrong with it!

16 thoughts on “ESP8266 Tuesday Update

  1. Hi Peter,
    Happy New Year! I was in your neck of the woods recently – I drove from Newcastle to Lancaster New years day. Took the A69 & then Alston & Hartside. I usually love that route but the weather was foul & Hartside cafe was closed:(
    I’ve not had a lot of time to play with ESP8266 recently but you seem to be doing it for me!
    I have a ESP07 which has a ceramic antenna and a connector for an external antenna, sadly I’ve not had time to test it yet.
    I’ll ask our RF guru at work. My intuition suggests that ceramic is best as it must be more expensive(?)
    Where have you seen these for <£2? I've never seen any 8266 at that price on Ebay.
    I've spent a little time producing a development board for my students:



  2. Hi everyone. I’m working on a solar powered esp board also, but I have chosen the LiFePo4 battery from A123. It has working voltage from 3.7v (highest max) to ~3.2v (2.8v is critical). While Li-ion can produce 4.3v (charged). I also have the LDO for protection, but with LiFePo4 it has higher efficiency.
    But the charging of A123 from solar panel has lower efficiency. Maybe will find a better boost+charger board later.

    The antenna comparison is also very interesting for me. Has anyone compared? I have ceramic antenna based boards. My friend, a low-level RF engineer said ceramic antennas are far more “stable”, while pcb-antennas my behave not so well in various humidity/temp environments. Maybe somebody has more info on this topic.

  3. Hi everyone!
    I’m also working on solar-powered ESP board. But I’m using A123 LiFePo4, it has voltage range from 3.65v (fully charged) to 3.0 (or 2.8 critical), but still using the LDO to avoid overvoltage. I haven’t found any reasonable Li-Ion cell -> 3.3v voltage regulator with good efficiency. So I used LiFePo4 battery, LDO regulator offers higher efficiency, comparing to Li-ion cell+LDO regulator (Li-ion produces 4.2v fully charged). The problem here, I have no integrated solution for Solar->LiFePo4 charging. So using non-efficient boost to 5V with LiFePo4 charging board. Hope to improve this circuit later.

    Antennas are also a very interesting topic. I’m using boards only with ceramic antenna. My friend, a low-level RF engineer, said the ceramic antennas are more stable. While PCB-printed antenna behavior may vary in different humidity/temp environments.
    Does anybody have any info on this topic? Any tests/benchmarks?

    • Solar powered. I’ve always wondered about this – so Lithiums must not be over-charged. I assume a solar panel capable of 4.8 volts max would solve that – also not over current – so you make it a small solar panel… so do we REALLY need a regulator?

  4. Hi Peter,
    The PCB antenna of ESP-01 is better than the ceramic on ESP-03 at least by the signal strength on my router.
    Thank you for this blog! 🙂

  5. Hello Peter,

    I have 20 ESP07’s for various tests and I am having my own issues with getting them to just work. I posted my issue over at
    Since you mentioned you have an ESP07 I would love to get your input on what the problem might be. I’m not yet convinced that I received a bad batch, I will be trying additional USB to RS232 TTL adapters (CP based instead of FTDI) shortly as well as different 3.3v power supplies. The funny thing is that I am able to use the same adapters and power supplies with the ESP01’s I have just fine, flashing away, normal running, etc.. Under the hood they are the same exact ESP8266EX chips, the only differences are antennas and the fact that more pins are broken out. These ESP07’s have me confused. I believe I have everything in order. If you have any input I would be thrilled.



  6. Hi Ian – you’ll see a recent (today) post on my blog in which I pointed to Banggood – 10 off under £2 each. They are also pretty good with the ESP-01 – I just recieved another 3 boards from them.

    Your board looks really NEAT… wish I was one of your students (ok, that’s a guess)….I need something to TINKER with these boards..

    Great stuff, I’m sure the students will be grateful for this opportunity,

  7. Hi Pete,

    I’ve just received my ESP-07 with ESP-12 footprint, mainly it is the exact same ESP-12 but with ceramic antenna.

    i have to say it looks great, I’ve loaded it with test sketch and was able to have a wifi signal through 5 concrete walls!

    Honestly I didn’t try the PCB antenna to compare it with the ceramic one, but I am serious impressed with the ESP wifi signal specially compared to nrf.

    BTW, I am not sure if you are aware of this project or not.

    There is a guy called Karang who is porting arduino library to ESP, imagine you could program ESP with the normal arduino code!

    I’ve tried it out and it is working great!

  8. It looks, Sameh as if you have reached the same conclusion as me… the NRF was a necessary evil as part of the learning path but ESP looks WAY better. I’m hoping this weekend to make my first remote sensor using MQTT – and from there – the sky is the limit – and thankfully thanks to MQTT now with some security!!

    I was NOT aware of the Arduino project and by putting this link in here I suspect you’ve probably made quite a few people’s day for them. As you’ve tried this out do you want to give a little more info – have you by any chance installed it all into the Windows Eclipse environment and if so could you do a step by step? Many of us would rather avoid getting back into that Linux learning thing if possible,.

  9. Well, Honestly I was very pleased with the Eclipse tool till I found that every time I want to try new project I have to ask the creator to add it or show us how to do it.

    I ended up by going the hard way, 2 days till I finally managed to install the toolkit on my mac book and working lovely. I am also able to try any project with the default make file.

    For the Arduino project you will find this discussion interesting, there is a guy who already tried it using the eclipse and i think was able to make it work.

    More links for everyone 😉

  10. Hi Peter,

    Your blog got me interested in home automation using MQTT. I am in the early stages, but succeeded to compile RSMB for my Synology DS214 with DSM 5.1 after reading the excellent tutorial on Primal Cortex’s weblog.
    RSMB tutorial
    You should try this as well. After installing VM payer on Windows and creating a Ubunto image the tutorial guides you through the rest of the process. I only has to change the download of the cross compiler the the correct version. Oh.. and /usr/local/bin did not exist on the diskstation, so I had to create this first before copying the files to the diskstation.

    The Ebay you referenced is also selling a ESP8266 development board with a unknown type of ESP8266 PCB. As usual there is no documentation for this board, but it seems you can experiment with a lot of features of the chip.
    Development board

    Thanks for the excellent blog so far.

  11. LiPo/LiFe batteries are great if handled correctly – easy to ruin if you don’t 😦
    Grab a solar powered phone backup charger from ebay to experiment…

    • Tell me if I’m wrong about these batteries – am I right in saying as long as the current is not excessive (would not be with solar) and you don’t go above 4.2v that does the job – presumably when fully charged they would achieve 4.2v and hence there would be effectively no charge current going through them?

  12. Ceramic antennas are more stable to external foreign (dielectric) objects getting near the antenna, e.g. plastics, water based objects like the human body throwing off the resonating frequency of the element. However, because the resonating element is loaded by higher dielectric ceramic material vs air and FR4 material from the PCB they will have slightly more loss (~ 1-2 dB) and narrower bandwidth (you will see different performance across the 11 channels) and typically some directionality (i.e. orientation can change RSSI by 5 dB). In addition the larger air loaded antenna of the esp-01 will gather more signal than the smaller ceramic loaded one.

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