FLIP_C3
An ESP32-C3 with a 60v tolerant 5v/2A buck converter & other special sauce.
v1.1 is fully compatible with 60v DC input with the major change being the addition of a bi-directional TVS diode on the input.
This transient suppression will enhance stability across the entire voltage range and generally strengthen the input side. It will reduce or eliminate failures from hot socketing in daughterboards and protect against damage from intermittently failing circuits, frayed wires, and shorts. High-vibration environments may find use, but ultimate endurance has yet to be tested.
1.0.x versions and earlier are susceptible to transients when connected live (including switching) to over ~50v causing permanent damage to the buck converter. Allow your battery to discharge before connecting. You may install a TVS diode in paralell with one of the input capacitors or use a pre-charge resistor to reduce these transients.
Summary
The first development board for the FLIP platform is an ESP32-C3 with a 60v tolerant buck converter meant for use with 12-48v battery systems. It is designed for use with ESPHome and Home Assistant, but can be flashed with other popular firmwares such as TASMOTA and WLED.
fartas
Specs & Features
On-board 5v/2A buck-converter tolerant up to 60v DC input
V1.1 - Full 60V input tolerance with transient suppression
v0.x.x - v1.0.x - 60v absolute max, do not live connect over 50v
Connect to battery when it is below 50v
Install TVS in parallel with input capacitor
Use a low value resistor to pre-charge circuit (pro move)
Low-profile press-in wire connector for DC input
24-16AWG Solid
22-18AWG Stranded - Ferrules are suggested
2x2P 2.54mm pass-through power header for stacking
Push release spring mechanism
ESP32-C3 designed for ESPHome and Home Assistant.
USB-C input for alt power and programming
Reverse current protection from DC input via diode
No data connection while powered by DC
LEDs on-board
WS2812B RGB -
GPIO8Digital output available on header as
L8to drive short runs
Red Status LED -
GPIO10
UART and I2C on Qwiic/Stemma QT compatible headers (SH 1.0-4P)
I2C:
SCL0/SDA1UART:
RX20/TX21
Boot Button
GPIO9Reset Button
ENABLE
ESP32-C3
The ESP32-C3 is considered a market replacement for the ESP8266 while bringing some features from the ESP32. It's a RISC-V platform with Wifi & Bluetooth plus support for Ethernet PHYs including the LAN8720 and W5500.
Our early planned product line should be more than covered by the capabilities of the C3... the biggest concern being limited to one I2C bus, but we'll cross that bridge when we come to it.
Pinout
5v
5v/2a from buck converter
3v3
3.3v/1a from linear regulator
SDA1
1
GPIO1 - Used as SDA on StemmaQT/Qwiic Connector and FLIP header compatible daughterboards
SCL0
0
GPIO0 - Used as SCL on StemmaQT/Qwiic Connector and FLIP header compatible daughterboards
RX20
20
Hardware UART RX - Reassignable
TX21
21
Hardware UART TX - Reassignable
LED10
10
Not connected to header pin
LED8
8*
*Connected to header via DOUT of onboard WS2812 for level shifting
9/BOOT
9
Hold button on boot to force bootloader mode - available as GPIO or on-board button in software
RESET
EN
Pulls EN pin low while pressed
2 - 7
2-7
GPIO Pins, check ESP32-C3-MINI-1 docs for special functions
License & Files
The FLIP_C3 is offered as open source under the Creative Commons 4.0 Attribution Share-Alike License (CC 4.0 BY-SA)
PCB
Original design was created in EasyEDA Pro and is available to download for yourself here. Recent versions of KiCAD should be able to import this, but you'll need to connect your own component libraries.
3D Model
EasyEDA provides a STEP file of the board which we bring into Onshape, align a vector of the silkscreen, and extrude it slightly. No bottom silkscreen at the moment. Download most formats from Onshape link:
Last updated
