A breadboard compatible Eagle breakout board for Espressif's ESP32 module ESP-WROOM-32.
I started with the schematic and layout from https://github.com/StudioSophisti/ESP-WROOM-32-Eagle-Breakout and heavily modified it for my purposes.
Pinout on the board corresponds to the WROOM-32 module pinout. This ensures shortest path connections with minimum vias.
Adequate power planes and heatsinking for the WROOM-32 module.
Multiple decoupling capacitors, including optional large low ESR tantalum (e.g. 330uF 6.3V). This will prevent brownout resets from current spikes when running off power supplies with limited current capacity.
Two voltage regulator options :
- LDO regulator - HT7833 / HT7333 in SOT89 package. HT7833 has a higher max current and higher dropout voltage - ok for USB power. HT7333 has lower max current and lower dropout voltage - ok for Lipoly battery power if not running at max clock frequency or not using the radio.
- Switching regulator (TPS82140) when efficiency is important and the source voltage can be up to 17V
LED on IO13. Pull-down resistor on IO2. Pull-up resistor on IO0.
No USB-UART chip on-board, to minimize deep sleep power consumption.
For testing/programming, if your USB-UART dongle 3.3V pin can provide enough power, short R3 and do not populate the regulator ICs. Otherwise, use one of the regulator options, provide power via VIN and leave R3 unpopulated.
The buttons, programming interface and regulator input pins have been placed on the edge to facilitate using the board in a case.
Pinout silkscreen on top AND bottom.
Board dimensions : ~ 36mm x 46mm
Resistors are 0603 package. Capacitors are 0603 except for C6 (tantalum C, e.g. 330uF 4V), C11 (tantalum B, can fit 220uF 4V). You can find suitable capacitors (0603 X5R, X7R) on Aliexpress and Ebay e.g. https://mcigicm.aliexpress.com/store/506373?spm=2114.10010108.0.0.15e3fdeesSP1Dd
Pcbway.com is an inexpensive pcb prototyping service I've used before : 10 PCBs (2-layer, < 100mm x 100mm ) for US$5 + shipping. Great quality, but in my experience, it takes about 4-5 weeks from order to delivery with their cheapest shipping option.
This layout is meant for manual assembly. I have placed vias in pads for shortest path to the power planes. The TPS82140 will have to be reflowed with the home-brew method of your choice - e.g. electric skillet. There's no need to risk reflowing the WROOM-32, just put thermal paste on the ground pad before hand-soldering the module pins.