ESP32 #74: on the Bench

On my Bench for the #ESP32.
18650 cell spacer and 3.7V Li-Ion batteries
cr123a 3V battery and holder
AA battery holder
smd micro usb connector
smd sd-card holder
color changing reusable silica gel
BF350-3AA strain gauge / pressure sensor
(HX711 Weighing Sensor / 24 Bit Precision A/D Module)
MAX3232 RS232 to TTL Serial Port Converter Module
R307 Optical fingerprint reader module
FPM10A Fingerprint Reader Sensor Module
TRINAMIC TMC2208 Step/Dir Drivers for Two-Phase Bipolar Stepper Motors
Buzzer
AMS1117 3.3V
xxx2302 N-Ch MOSFET
2N7002 N-Ch MOSFET
CP2104 USB to UART
ESP32 WROVER Adapter (see • ESP32 #68: KiCad ESP32... )
...
and more

[@liftbigeatbigvideo]

I dig it

[@pverbakel]

I liked the ESP32 WROVER Adapter board. Can you share the cad-file?

[@pcbreflux]

You can have a inside look here ruclips.net/video/lAs_SSnsrNI/видео.html and the KiCAD and gerber files are here github.com/pcbreflux/espressif/tree/master/esp32/kicad/ESP32-wroover-adapter.

[@pverbakel]

Great! Thanks!

[@AltMarc]

The TMC shouldn't be a problem, there's a library for arduino. Nicer would be, it's big brother that can run external mosfets...

[@pcbreflux]

Thanks, will have a look.

[@AltMarc]

YTber. Marco Reps did talk about it, AND got the lib dev, YTber. GRrainmaker commenting on its video :
ruclips.net/video/ZzO9skEYqwY/видео.html

[@wi_zeus6798]

I hope you are aware of the fact that you bought fake, possibly dangerous and pretty much useless (depends on the usage scenario) batteries...
Otherwise great video! Keep up the good work. Viele Grüße

[@pcbreflux]

Thank you, really have no source for cheap but good cells. Even the transport costs and crossing the borders can be an expensive issue. Do you have a good and cheap source in germany?

[@mahmoudkortas]

Hello
Please tell me how can i recive data put by a client in website hosted on the esp32 ?

[@pcbreflux]

See ruclips.net/video/4bS5ktABELE/видео.html for some data or ruclips.net/video/_mJL2LoxhQQ/видео.html to exchange a file, maybe way over-sized with the SSL/TLS for your purpose. But in general the ESP32 Web-server receive the HTTP request (or HTTPS or other like websocket) from the client and parse the request and do what you have programmed. To start have a look at the Arduino SimpleWiFiServer.ino (WiFi Web Server LED Blink) example. But you can also use other OS for the ESP32 (like MongooseOS, MicroPython or Duktape or other) to host a website on the ESP32.

[@nikomo]

For the love of all that is holy, do not populate an entire spacer and then hook the entire thing up in parallel.
If one of the cells fails, every functional cell will short-circuit through the dead cell and you have a fire on your hands.
Look into pre-built BMS solutions if you can't be bothered to build one yourself.

[@wi_zeus6798]

nikomo good point!

[@thejackofeverything7961]

it is common practice to fuse every connection, and this fellow seems to be smarter than a child.

[@pcbreflux]

Thanks, for long time I read a lot about the ISL94212, ISL94203 and other Multi-Cell Li-Ion Battery Manager solutions, but then I also read other source and want to try it myself like this channel HBPowerwall (think even tesla do this in big chunks of parallel 18650 blocks). Even if it fails I learned something ... (yes, I will consider safety ...)

[@klassichd10]

Thanks for sharing your bench.
Before buying LiIon Batteries I look at lygte-info.dk where may independant test results can be found. as well as some teardowns of fake cells with huge numbers printed on and less material built in. There you can also find Tests for protected cells.
The last Serial Printer I owned was a mechanical Teletype with Punch tape Equipment. Some decades ago....
I also used such an optical finger print sensor with an ESP8266. It should help my mother to access her house and to avoid a full-time care, but it did not work for her. Worked well for me and others but she was no more able to use it properly. So I solved this issue using a RFID tag Reader (and a piezo buzzer as acknowledge signal). I activated the finger print sensor with a FIR Motion sensor. Maybe a cheap Radar sensor works too, but was not avalable that time. The cheap Radar sensors need a extra linear voltage Regulator (7805), the ESP supply is too noisy. The door itself is opened bey Homematic Keymatic.
Marco Reps showed the Trinamic Driver. very impressive.
The AMS1117 hat lots of quiescent current. Maybe you want to test some Holtec Regulators, like HT7333 ?
The 2N7002 is a 5V but not a 3.3V type, but with 60V robust. The Si2302DS fits better, it is a even 2.5V compatible similar as the cheap AO3400 which is a 30V type and a Little more robust.
Have fun!

[@pcbreflux]

Thanks, just started with the 18650s and still have a lot to learn. And for others I don't recommend to buy the cheapest cells but I want to compare the performance of different cells myself and sure the written capacity is far from reality.

[@bogusbyte]

Why are you buying fake 18650???? 9600mAh????

[@rraymakers]

that was my exact same thought 30 seconds into the video.
the good stuff:
Panasonic NCR18650PF
Panasonic NCR18650B
Samsung ICR18650-26F
Samsung INR18650-25R
Samsung INR18650-30Q
Samsung INR18650-35E
LG INR18650-HG2
LG ICR18650-HE4
Sanyo NCR18650GA
Send me a message to get an Excel that does some calculations if you want to put them in a pack

[@pcbreflux]

Thanks, yes I am aware that the cheap cells maybe have just a 10th (or even less) of the capacity, but this was just for testing. More cells on the way...