It’s 5 O’clock Right Here

Just came back from Cancun, a little darker and a lot heavier. If you’ve ever been there, you’ve probably heard “It's 5 O'Clock Somewhere” at least once. Obviously, I don’t drink, nor do I encourage drinking, but every time I hear that song I can't help but wonder “where in the world is it 5 O'Clock right now?” (seems pointless since I’m already on vacation, but bear with me here). With no Googling device in sight and in fear of my fellow beach dwellers ostracizing me, I kept it to myself.

Today, I will build a solution to solve that problem. You might be thinking, “why can’t I find a solution to a more pressing issue like people reserving pool chairs all day without using them?” to which I answer, “being useful is the opposite of being in Cancun”. What say you, Senator?

With that out of the way, we will use M5Stack Core 2 since I have not received anything as good in a while (hint). To make it more challenging, we will use MicroPython. I like ESP32 and I like Python so mixing the two would be a great idea, right?

To get M5Stack Core 2 ready for MicroPython code we head over to:

https://github.com/lemariva/micropython-core2/tree/master/firmware

and download lv_micropython_m5core2_bf62dfc784_esp32_idf4_4_x.bin

There are more options for MicroPython bin files on the interweb, but this is the one required the least amount of work on my behalf.

We can use https://espressif.github.io/esptool-js/ to erase flash then program ESP32 with bin file. We could also run the following two commands after updating COMPORT and file location if we have esptool locally.

esptool.py --port COM3 erase_flash
esptool.py --port COM3 --baud 460800 write_flash -z 0x1000 C:\Users\me\Downloads\lv_micropython_m5core2_bf62dfc784_esp32_idf4_4_x.bin

One more option to prepare ESP32 for MicroPython is using Thonny since this is the IDE we will use to write our code.

We need to access the internet with M5Stack Core 2. Instead of hardcoding Wi-Fi credentials we will use WifiManager. That code will try to connect to the last Wi-Fi used. If we never used any Wi-Fi or it is not accessible at the time, WifiManager will serve a page that we can access to tell M5Stack Core 2 which Wi-Fi we want it to use. In order to get to that page, we have to connect to M5Stack Core 2 Wi-Fi (in my code ssid is WifiManager and password is dfdfdfdf). Once we're connected, we use the web browser to go to 192.168.4.1.

To recap, using a smartphone we leave our internet Wi-Fi and join M5Stack Core 2 Wi-Fi. M5Stack Core 2 will then try to connect to internet Wi-Fi using the information we provided.

Almost forgot another cool feature of WifiManager; if it finds an open network it will try to connect to it automatically, so you don't have to use your phone. Pretty neat, isn't it?

Please note that Wi-Fi credentials will be stored in wifi.dat in clear text on ESP32.

Next, we examined the HTML of https://www.timeanddate.com/worldclock/ to find cities with 5 AM or PM in time. We took that HTML as string and easily split it to get cities and day/time which is probably the only advantage of using MicroPython here.

The main code is in main.py so it will be executed on device boot (after the optional boot.py, of course). The second MicroPython file is wifimgr.py which contains WifiManager code we talked about earlier. The last MicroPython file is ScreenText.py which contains functions to be accessed by the other two MicroPython files to update text on the screen.

Finally, added cancun.png as a background for M5Stack Core 2 display.

In case you're wondering, I left Cancun on my own will and power.