FLIP_C3

Tip

v1.1+ contains transient suppression allowing safe connection across the full 6-60 voltage range, specifically when connecting live over 50v. Since this update we have had no reported failures of the buck converter. If using an older board version, please take appropriate precautions.

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.

Now with official WAGO spring connector

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 - GPIO8
    • Digital output available on header as L8 to drive short runs
  • Red Status LED - GPIO10
• UART and I2C on Qwiic/Stemma QT compatible headers (SH 1.0-4P)
  • I2C: SCL0/SDA1
  • UART: RX20/TX21
• Boot Button GPIO9
• Reset Button ENABLE

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 SPI Ethernet PHYs like W5500.

Pinout

Pinout of the FLIP_C3 - Ignore call-out on v 1.1

Pin Label	GPIO	Notes
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

Home Assistant

BLE Improv

If you have the Bluetooth integration active in Home Assistant, you may be able to configure your FLIP_C3’s Wifi credentials directly. Hit the blue button below to check your integrations page.

WiFi

Your FLIP_C3 will also create a Wifi access point as a backup.

network: flip-c3-xxxx
pass: GenericPassword

It should automatically present you page to set your WiFi credentials, but if not, visit http://192.168.4.1/ in your browser.

Check your Home Assistant notifications or Integrations page to adopt your FLIP_C3 as an ESPHome device.

ESPHome

It may behoove you to adopt into ESPHome Builder add your additional configuration before adopting into Home Assistant. Until you adopt into ESPHome, you will only have access to the following entities:

• 1x RGB LED
• 1x Red Status LED
• BOOT Button on GPIO9
• Reboot Button
• Hours Counter* (some installs)
• FLIP_C3 Internal Temperature

If you change the friendly name or hostname in ESPHome, you may need to delete and re-adopt the device into Home Assistant for these changes to be seen.

USB Recover

Use the Connect button on the top left corner of this site to re-flash your FLIP_C3 over USB directly in Chrome or Edge.

Troubleshooting

You may need to hold the BOOT button as you connect the USB cable. Alternatively you can hold the BOOT button while you press and release the RESET button if the FLIP_C3 is already connected via USB-C. Hold the BOOT button for a couple seconds after the device is connected to your computer and then proceed with the installation above. Once complete, power cycle the FLIP-C3 with the RESET button or disconnecting and reconnecting the cable. You can also use this time to swap to a DC power source via the 2P spring connector.

Adopt In ESPHome

Once you’ve followed the steps to connect your FLIP_C3 to Wifi, you should see it in the ESPHome dashboard available to be adopted. Adopting into ESPHome will generate a base YAML that references our YAML file on Github as an external package with the following lines:

Caution

24.09 - Our config files were moved into a separate repo, please change your existing package URL to the following for the latest updates.

packages:
  vdbxio.FLIP-C3: github://vdbxio/esphome-configs/flip-c3.yaml

This includes references to all the basics of the hardware and more. This includes the onboard WS2812, the red status LED, the Boot Button on GPIO9 and I2C is defined at id: bus_a

You can add ESPHome YAML to the end of this to get started quickly.

YAML Reference

The following are snippets to properly interact with FLIP_C3 hardware in ESPHome while direct reference to the YAML we ship is available on Github:

https://github.com/vdbxio/esphome-configs - Active repo as of 24.09

Board Definition

If you like, you can easily start a blank ESPHome device based on the ESP32-C3 using esp32-c3-devkitm-1 board type. This is default in ESPHome for C3 based boards and we use chip level pin numbers on our silkscreen.

esphome:
  name: bare-minimum
  friendly_name: Bare Minimum

esp32:
  board: esp32-c3-devkitm-1
  framework:
    type: arduino

Boot Button

The BOOT button is available in software on GPIO9 after boot. If held during boot, FLIP_C3 will be put into bootloader/flash mode.

binary_sensor:
  - platform: gpio
    name: Boot Button
    pin:
      number: 9
      inverted: True
      mode:
        input: True
        pullup: True

WS2812

light:
  - platform: esp32_rmt_led_strip
    id: onboard_rgb
    rgb_order: GRB
    chipset: ws2812
    pin: 8
    restore_mode: RESTORE_AND_OFF
    num_leds: 1
    name: "RGB LED"

Status LED

light:
  - platform: status_led
    name: "Status LED"
    id: status_led
    pin: 10

WLED

Get started with WLED

WLED is designed for running addressable LEDs on ESP32 based devices and the FLIP_C3 is a great board for running it.

Use the installer at install.wled.me ->

SETUP

Under LED Settings:

Set GPIO8 noted as L8 on the FLIP_C3 to use the onboard WS2812 as a level shifter. Increase your LED count by 1 to include this pixel. If you are close enough to your first pixel, you may be able to get a stable output from any other pin. Using anything but WS281x pixels on L8 may cause unexpected results.

Set GPIO9 as the button if you want to use the BOOT button on the face of the FLIP_C3

In the main interface

Use segments to separate onboard WS2812 from the rest of your strip.

Notes:

If using 5v LEDs with the on-board buck converter make sure not to exceed the 2A/10w current rating which is about 100 LEDs at full brightness.

The FLIP_C3 will get extremely hot over 1A. It should be able to maintain up to 2A in open air, but consider cooling when installing in an enclosure. Do not touch on-board components when in operation.

Changelog

Board dates are batch number referenced to a version number, though we haven’t yet done any duplicate production runs of a single version.

• 26.06 - v1.3 - Modernization
  • Replace TE spring connector with WAGO
  • Add GPIO2 pull-up for stability
  • Add 3V/5V jumper selector for Qwiic connectors
    • 3V Default - considering 5v in future.
• 24.07 - v1.1 - full input transient suppresion
  • Add TVS diode to input -
  • Move LED10 further from keepout zone - it has the room
  • Tweak inductor position lower
• 23.12 - v1.0.1 - Prep for early 2024 production
  • Moved C14 closer to EN pin
  • Research potential replacements for L1 based on price and availability
• 23.08 - v0.9.4 -
  • Original DC spring connector only grabbed the tip of standard length ferrules making solid core wire the only real option
    • second option was too small & original is now discontinued - 0.9.5 is on the way with third option
  • Instead of presenting GPIO8 directly to the pin header which is used for the onboard WS2812b, we now route the D-OUT from the on-board WS2182b to an “L8” pin so it be used as a level shifter for short runs.
• 23.04 - v0.9.1 - Switching Buck Regulator
  • LMR16020 - tested to work from 5 to 58v with only FLIP-C3 as load
    • higher voltages seeing upwards of 0.6v wobble on output
    • output is up to 0.7v higher at 58v input vs 5v input
  • Missed output ground on test board and poor placement of VREF
• 23.04 - 0.9.0- LDO circuitry is not going to work, back to the drawing board.
  • Design and order tester for switching buck
  • Remove LDO circuitry from FLIP-C3 and reconsider footprint size.

BOM Alternates

The retail version of the FLIP_C3 is currently manufactured by JLCPCB using their parts library. While it is said that JLCPCB uses their sister company LCSC for parts, the two companies usually have different stock. This is a living document of potential alternates for major parts including those used in production or considered for production. This document can be used in case of stock declines or discontinuation of parts. Basic passives like resistors and capacitors may not be included as this is intended for major functional parts and those parts can be easily replaced with a simple search when using the BOM directly from the EasyEDA files.

I2C & UART Connectors

For Qwiic and Stemma QT compatibility we use JST-SH1.0 connectors based on SM04B-SRSS-TB(LF)(SN) via reference document from Sparkfun

A second connector is used to connect to the RX/TX lines on GPIO 20/21 alongside GND & 3v3 in the same order as the I2C connections on GPIO 1/0 - See PINOUT

LCSC	JLCPCB	Production	Price	Notes	Datasheet
C145956	C145956	up to 1.0.0	0.0591	Discontinued on JLCPCB	C145956.pdf
C3029343	C3029343		0.0498	thicker walls, better footprint?	WAFER-SH1.0-4PWB.pdf
C7430446	C7430446		0.0393	thicker walls, better footprint?	ZX-SH1.0-4PWT (1).pdf
C160404	C160404		0.123	JST original spec	SM04B-SRSS-TB(LF)(SN).pdf

ESP32-C3

There are two variants of the ESP32-C3-MINI-1 module. The H4 variant has a higher temp tolerance than the base model N4. We’ve focused on using the H4 variant, but supply chain issues could lead to us using the N4 model in some production runs.