mike-rankin / esp32_pico

ESP32 Pco D4 project with 0.66" Oled Display

ESP32 Pico

ESP32 Pico D4 project with 0.66" Oled Display This design was an experiment using new to me parts like the ESP32 Pico D4, 14500 LiPo battery, 1mmx1mm RGB led and a metal wifi\bluetooth antenna. It can be powered off of a battery or USB cable. If a battery is inserted and USB cable is plugged in it will charge the battery and power the board. This project was not created for any specific purpose but just an excuse to test out a few new parts. If you come up with an idea for this hardware then just let me know at @mikerankin

https://youtu.be/WG5k9fxXMjg

The bare PCB was provided by PCBWay and parts by LCSC.

esp32_pico's Issues

How are the values of L1, C3 and C4 for antenna decided?

Hi,

Thank you for open sourcing this project. I am looking to design my own board and I'm stuck on the values of antenna caps and inductor. I understand that the impedances of the PCB and the ESP chip need to be matched. In the datasheet, these values are marked as 'TBD'.

My question is how did you come up with the values of C3 (47 pF), C4 (2.7 pF) and L1 (1.8 nH)? Did you experiment with different values? Do you expect these values to work on a different board? Are there any rules of thumb about deciding these values? As you can see, my knowledge on RF is minimal, so please share any thoughts that you think a beginner should know. Thank you very much!