ESP8266: ESP-201 breakout board review

Do you like this post? A regular project like the PlaneSpotter Color takes many hours of my free time to develop and maintain. Would you offer me a beer for my hard work if I was your neighbour? Modern technology called teleportation makes it easy to send me a beer. Just click here. Thank you!

Today finally a new package from China arrived containing an ESP8266-ESP201 bought on aliexpress. I had ordered two pieces and each came in a little plastic bag and stuck in protective foam. The bag also contained a tiny antenna that can be plugged into the connector on the board.

Pin layout to your convenience: when plugged into a breadboard
you cannot read the labels on the lower side of the PCB
Please Note: GPIO15 remains connected even after flashing

Board

I ordered the ESP-201 board because I was looking forward to finally own an ESP8266 module which was compatible with my bread board. Annoyingly the connectors for power supply and serial connection are placed in a way which by default doesn’t fit into a normal breadboard. You can however use pliers to bend the four pins in a 90 degree angle so that you can attach the connectors right to it (see picture):
ESP8266 ESP-201: bend TX, RX, 3.3V and GND
pins to fit the module into a bread board
Another annoying design mistake is that the labels for most of the pins are on the bottom side of the PCB. You can’t read the labels when the module is sitting on the bread board. Because of this I drew up the pin layout above. I hope it will help you…
The bottom side of the ESP201. As
you can see, the pins are nice labeled,
just on the wrong side

Flashing Firmware

It took me a while until I figured out that I also had to connect GPIO15 to ground in order to get the board running. After that flashing worked fine and I could transfer the NodeMCU firmware without further problems to the chip.

Available Pins

It seems that all the usual pins are available. See this table here for mapping from the labels on the bottom of the field to the once often used in forums and other sources: https://github.com/esp8266/esp8266-wiki/wiki/Pin-definition
Especially noteworthy is the availability of the T_OUT pin which is the analog-digital-converter (ADC). I’m not 100% sure what the D0,D1, D2 and D3 pins are for. It might be that the are used for the SDIO mode, where you boot from a SD card.

Antenna

The board appears to have a built-in antenna but also offers a connector to the antenna that came with the package. The following table shows the average signal strength of (anonymized) access points in my neighbourhood after running the wifi.sta.getap command on the lua firmware 100 times. Once with the external antenna and once without:
# of access point listed avg signal strength [dbm]
w/ ext antenna w/o w/ ext antenna w/o
AP-1 100 97 -70 -82
AP-2 93 18 -88 -92
AP-3 2 0 -92 n/a
AP-4 94 1 -86 -94
AP-5 4 0 -93 n/a
AP-6 16 0 -89 n/a
AP-7 99 97 -80 -84
AP-8 19 0 -91 n/a
AP-9 5 0 -92 n/a
AP-10 100 100 -31 -32
AP-11 100 100 -31 -32
AP-12 98 87 -89 -91
AP-13 40 0 -92 n/a
AP-14 4 0 -91 n/a
AP-15 1 0 -91 n/a
AP-16 16 0 -93 n/a
AP-17 13 0 -93 n/a
AP-18 81 92 -89 -92
AP-19 22 0 -90 n/a
AP-20 47 38 -91 -92
AP-21 99 75 -78 -89
AP-22 95 87 -81 -89
AP-23 6 0 -90 n/a
As you can see, 12 access points were not even visible without the external antenna. All others had significantly worse signal strength without antenna. I realize that this test is not highly scientific but it might give you an idea how valuable the external antenna is.

Chip

My two boards are equipped both with the newer ESP8266EX chip. If anybody knows what the difference is to the version without “EX” please let me know. Nodemcu’s node.info() returns these values:
flashisize flashmode flashspeed
512 0 40000000

Quality

The board looks well processed but one of the two pieces came with pins not 100% perpendicular to the PCB. However, this doesn’t affect usage since both rows of pins are equally skewed.

Summary

If you don’t mind adapting some of the pins with pliers you get a great test board for a really good price (I paid $4.69, by now it’s even cheaper). Once adapted the module fits nicely into a bread board and you have one row of connectors left on each side of the board. It is a pity that the pins are only labeled on the bottom side but that might be changed in the future. However, for a price only slightly higher than a ESP-01 it is a pretty good module and has many pins more broken out as well. Especially the ADC offers new possibilities for experimentation. Just remember that the ADC measures values between 0 and 1V. The external antenna and the connector on the board is another aspect on the plus side. It is quite impressive how much more sensitivity this 15cm wire yields.

Links

 

Related Products:

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Posted by squix78

40 comments

  1. Observation, you could pull the weather icons from the Weatherunderground server rather than host them yourself. I think they do-not apply any read quotas.

    Did embedding the icons in flash prove to be too great an overhead?

    1. Hi David. If I’m not mistaken these icons are from a 3rd party (which reminds me to put their credits up). So I’d have to host it somewhere anyway. I currently also only use uncompressed bmp format and I doubt that any reasonable person still has them around for normal use;-). And then: downloading has the advantage to be easier to change compared to embedding in the firmware… But it was a design decision. Comparing pros and cons…

    1. Hi Stephen. I plan to upgrade the plane spotter project to the color screen, so yes, it’s definitely possible. Just a question of time:-)

  2. Hi,

    I have a working esp8266 weather but the small LCD only.
    im trying this one as i have the exact LCD lying around. i saw the “settings.h” where values need to be changed. (i.e. wundeground API, country, city, etc).. the only one that i was not sure and I did not see any explanation was the ThingSpeak value.

    May i ask what is the purpose of the Thingspeak value? i tried to view it but I think its a private channel.

    Anyway, i uploaded it on NodeMCU and when i inspect the Serial monitor, i can get to the part where it downloads the pictures.
    Here is the last bottom lines on the Serial.
    There is a line that says “connection failed.”…. Im guessing it has something to do with the Thingspeak..or maybe something else..

    …….(lots of downloding lines here…………..)
    Downloading http://www.squix.org/blog/moonphase_L19.bmp and saving as /moon19.bmp
    Downloading http://www.squix.org/blog/moonphase_L20.bmp and saving as /moon20.bmp
    Downloading http://www.squix.org/blog/moonphase_L21.bmp and saving as /moon21.bmp
    Downloading http://www.squix.org/blog/moonphase_L22.bmp and saving as /moon22.bmp
    connection failed
    connection failed
    connection failed
    connection failed

    Loading image ‘unknown.bmp’
    File not found
    Loading image ‘/mini/unknown.bmp’
    File not found
    Loading image ‘/mini/unknown.bmp’
    File not found
    Loading image ‘/mini/unknown.bmp’
    File not found
    Loading image ‘/moon0.bmp’
    File not foundconnection failed
    connection failed
    connection failed
    connection failed

    1. Hi Glenn,
      The purpose of the Thingspeak channel is to display (say) your own local temperature and humidity. So I have an ESP8266 and BME280 sensor running that reports every 10-mins to thingspeak the current temperature and humidity in my garden. Therefore I provide the keys for my channel and it gets reported on the weather display. Ideally there would be a software (compile time) switch to remove that option.

  3. Please ignore the comment below.
    I was able to solve it. Apparently, the wifimanager didn’t connect successfully to my router, so i had to manually connect and put the static SSID and password.

    So its working now, yey! i can see the pictures and the icons properly.

    im still dumbfounded with the Thingspeak channel in the settings.h.
    May i know if that is really needed?

    1. Hi Glenn, I’m a program newbie and met same message from serial port, but I struggled for long time but cant overcome this issue, do you mind give me some suggestion?

      Thanks!

  4. Hi,
    Is there any chance regarding tutorial how to call bitmaps using WiFi connection?
    I want to prepare own set of icons but I don’t know how to use it in your script 🙁
    As well I have a question reagrding screen refreshing, as I see that is the issue when the time is updated and some pixels are not removed?
    Thanks in advance for help.
    Piotr

  5. Very impressive weather station, works great!
    If it could automatically update summer/winter-time, it would be absolutely perfect.
    Have fun with the beer 😉

  6. I was able to get this running, but wanted to mention a small issue I ran into. (Sounds like the same one Mike McRoberts references.) The bitmaps require more than 1M of SPIFFS, so if you were like me and had selected only 1M at compile time, you run out of space to download all of the bitmaps, and many of the moon-phase bitmaps will fail to download, or will be perhaps truncated or corrupted. I went back and changed to 4M (3M SPIFFS) in the IDE and was able to solve this. Still having a bit of overlay issues with the time updates, but as Daniel mentioned, the code may still need a little work.

    Thanks for all the effort on this…now to add some of my own tweaks!

  7. Hi Daniel,
    i tried to flash the script but i will receiving all the time the following error:
    *******************************
    In file included from esp8266-weather-station-color.ino:34:0:
    C:\Users\Jens\Documents\Arduino\libraries\esp8266-weather-station-color-master/WebResource.h:25:31: fatal error: ESP8266HTTPClient.h: No such file or directory
    #include
    ^
    compilation terminated.
    Fehler beim Kompilieren.
    *******************************
    I added the ESP8266HTTPClient-library to the Arduino 1.6.5 but there is still the same error.
    Do you have any idea what i can make that the script will runing?
    Jens

  8. Unfortunately Banggood.com are no longer stocking the 2.2 Inch Serial TFT SPI Display ILI9341 display! Can it be obtained from another supplier? Or can an alternative be used?

    I would like a bigger screen for my PlaneSpotter project so that I can enclose everything in a case with the lcd screen acting as a box top : )

  9. Dani, excellent! Built this over the weekend (preparing to teach another IoT class this week) and almost worked flawlessly (2.4″ TFT + Wemos D1 Mini). Couldn’t get the WifiManager to connect, tried a few different things then finally went manual mode. The 199: timeClient.updateTime(); would sometimes hang, changed the .h to use “us.pool.ntp.org” instead; didn’t do a lot of troubleshooting, was more in quick-fix mode. Maybe later this month I’ll try incorporating Neptune’s daylight savings code back into this (thanks btw for the link to that). PS will try to get some pictures with the kids doing projects over the session the next two weeks. Regards, Mike

    1. Mike, you stated that you changed the .h to use “us.pool.ntp.org”. What is the path/filename to that .h file?

  10. Dani,

    I’ve been adding some of my own enhancements to your original code for several weeks now, and thought I’d share some of my changes in case anyone was interested. I’ve posted these on GitHub if you’re interested…https://github.com/fowlerk/ESP8266-Color-Weather-Station-v8 .
    This version includes many enhancements to the displays (see the README on GitHub), along with Neptune’s enhancements for daylight savings time. The code could stand some clean-up, but otherwise seems to work well.

    Let me know what you think…I’ll post some photos of the displays when I get a chance.

    Keith Fowler

    1. Hi Keith

      You put some really nice things into the code! I knew that the WifiManager had this configuration UI feature but never got around to use it in my code. Now with your code I have a very nice example to use it;-). Thank you a lot for sharing! I just posted your fotos on Twitter and linked to your repository, I hope you don’t mind.

      I am working ATM on a 2.4″ display with touch. This would allow to switch screens or similar…

      Dani

      1. Dani…I don’t mind at all, in fact I’m honored. One thing to note, which I pointed out in the README on the repo, is that I have added a few fields over the past few months that may (or may not) have made it into the Weather Station library for the Weather Underground functions. Not sure how exactly to go about getting those into the master. (You may even be able to spot these on some of the displays.) I did not put those library changes up on the repo.

        I’d also had my eyes on those touch-screens and had similar thoughts on using them to control the screen displays. I’m anxious to see what you end up doing with it. Your projects always give me more ideas to try ;).

  11. Hey Dani and Keith, I just tried this out a few days ago and love it. Just wanted to confirm that when I tried to use Keiths’ version, it failed to compile due to the changes in the Weather_Station library. I would really like to try out this version if one of you could point me at the correct library.
    This was my first project with an esp8266 and I am really surprised at how powerful and easy it is to use.

    Kevin

    1. Kevin…yes, sorry, I knew that would bite someone. I really wanted to get the changes merged into Dani’s master library rather than start off on another branch. In the interim, I have uploaded the two changed library files for the Weather Underground components to a separate folder on the repo if you want to download those to (temporarily) replace the original ones in the Weather Station library. That should allow it to compile. Let me know if that doesn’t work for you. Hopefully I’ll figure out the right (permanent) solution to address the changes soon.

      Keith

      1. Thanks for the update Keith,

        I got the new code and everything works great. Now I just have to figure out how to make it work with a bigger screen, maybe 7 inch. My eyes ain’t what they used to be. 🙂

        Kevin

        1. Glad you got it working Kevin…and I know what you mean about the old eyes! I’m right there with you. I’m torn between the compact size and being able to read all the data displayed without my glasses ;). Let me know if you find a bigger option that works well for a reasonable cost.

  12. Dani…just made a pull request on your repository to add some of the changes I had made to your Weather Underground library. Let me know if you have questions or issues.

  13. Dani, I just made another pull request for some new updates to the Weather Underground client library. These include changes to support some additional enhancements I have been working on recently that display weather alerts (as per the WU API call “/alerts”), as well as the addition of probability of precipitation (PoP). I have uploaded a new version to my repository on GitHub that shows these additional enhancements (see the README for further details), along with screenshots.

    As always, let me know if you have any questions or issues, and best wishes for the upcoming holidays!

  14. Hi Daniel. I don’t like the Ardunid IDE because of the lack of debugging with breakpoints. Therefore, I’ve just started with VisualGDB and JLink debugger and ESP8266. I have quite some difficulties.

    Do you have any experiences with VisualGDB?

    By the way: I am situated near Zurich and I like your projects! Great work!

  15. I have been having a lot of fun working through the examples with your weatherstation library. I bought your kit, which was an easy way to get started with the ESP8266.
    I am working through the WeatherStationDemoExtendedDST, for some reason updateData is not firing every 10 minutes. updateDHT is working fine, fires every minute.
    I think this is where the problem is, it isn’t setting readyForWeatherUpdate to true. However, it looks exactly the same as your other examples.
    if (readyForWeatherUpdate && ui.getUiState()->frameState == FIXED) {
    updateData(&display);
    }
    Thanks for any help.

  16. Figured it out. Apparently you can’t attach two events to a single ticker? I created two tickers, and now it works.
    tickerUpdateData.attach(UPDATE_INTERVAL_SECS, setReadyForWeatherUpdate);
    tickerUpdateSensor.attach(60, setReadyForDHTUpdate);

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