Need technical details on ESP32-MINI-1-N4

[ESP_Sprite]

All those pins together are the EPAD. They're internally connected together on the module. Feel free to connect them all to GND.

[Brijesh]

OK. THEN ALL OF THEM WILL CONNECT WITH GND.

THANKS,
BRIJESH K

[Brijesh]

I do have tow more queries

1) if i do not use integrated RTC of ESP32-MINI-1-N4 then can i use both the pins Pin11 & pin12 as normal GPIOs? I will not connect 32.768KHz crystal in this case.

2) I have seen that in GPIO0 & EN pins play role to enter module in download mode so suppose if i have to use manual download mode then can i do connections as shown in datasheet schematic? What should be value of pull up resistor and capacitor connected on EN pin?

in some modules i have seen that they use USB-UART chip for automatic download mode but is there any drawback of the manual download mode? is manual download mode safe to use?

Thanks,
Brijesh K

[ESP_Sprite]

1) if i do not use integrated RTC of ESP32-MINI-1-N4 then can i use both the pins Pin11 & pin12 as normal GPIOs? I will not connect 32.768KHz crystal in this case.

Yes, you can.

2) I have seen that in GPIO0 & EN pins play role to enter module in download mode so suppose if i have to use manual download mode then can i do connections as shown in datasheet schematic? What should be value of pull up resistor and capacitor connected on EN pin?

in some modules i have seen that they use USB-UART chip for automatic download mode but is there any drawback of the manual download mode? is manual download mode safe to use?

Yep, if you implement the things in the schematic it'll work in manual mode. Difference is that you need to bridge JP2 and press SW1 every time you want to program the board, and un-bridge JP2 and press SW1 after programming is done. The auto-download circuit does all that for you.

R1/C3 depends on how quickly your power rails come up; check the ESP32 datasheet for more details. In general, if you are making something that runs off power rails that come up fairly quickly (e.g. you're powering your thing from USB), 10K/100nF is a good value if you don't use an auto-reset circuit; I'd try 10K/1uF if you do use one.

[Brijesh]

OK thank you so much for quick reply. Will take in design.

appreciate your prompt reply.

Regards,
Brijesh K

[ESP_LJH]

You could consider pin 55 is a composite pad with 9 small pads, so there is no problem with schematic and pin layout. Then as the pin layout shows, conenct this pin 55 all to ground.

[Brijesh]

1) OK but I have connected all pins to GND in Schematic like as attached. Will it work?

2) I need one more help from you please.

I am planning to use PT100 sensor in my design and i do not know how to connect PT100 with ESP32 Mini ADC Pins because I think PT100's output voltage may be very less (mV) and ADC range i checked it says (100mV-2450mV) so may be need to add OP-AMP circuit on PT100 output then connect with ADC input of ESP32 Mini.

Overall concept I know but don't know how this is done in schematic if i have to implement. so do you have any suggestions for same i mean which OP-AMP to use and how to do all connections?

if anyone has used PT100 with ESP32 in any design then also please suggest.

Thanks,
Brijesh K

[Brijesh]

Hello,

Can you please reply me for my previous post queries?

Thanks,
Brijesh K

[Brijesh]

Hello,

I have found one OP-AMP based design of the texas instrument can i use it using some modifications to measure temp using PT100 with ESP32?

There is one exl sheet (Attached here also) in which we can add parameters like desired temp measurement range , Desired output voltage range of Op-AMP and Vref supply. After entering these all parameters it provides results (table) & implementation related to it using OP-AMP.

1) Just I am not sure here what ref voltage should I give 3.3V OR 2.5V?
2) Also how much max output voltage of the Op-AMP can i feed into ADC input of the ESP32? so that i can set output voltage accordingly.

I have attached exl sheet can you please look into it and suggest?

Thanks,
Brijesh K

[Brijesh]

Hello,

When I can expect reply?

Please request you to reply ASAP because based on it we are planing to go ahead.

Thanks,
Brijesh K