Question 1

How to put LEDs on an RC car?

Accepted Answer

You need an Arduino ESP32, LEDs, resistors and the Flare RC app. The app guides the entire process: wiring diagrams, code download, board flashing and Bluetooth calibration. Total budget: about €28 per car in parts.

Question 2

Do I need electronics knowledge?

Accepted Answer

No! The Flare RC app is designed for beginners. It provides clear diagrams, step-by-step guidance and automatic calibration. The only operations required are: connecting wires on a PCB universel and flashing the code (guided).

Question 3

How many LEDs can be connected?

Accepted Answer

The system supports 13 LEDs on dedicated pins: 2 headlights, 2 brake lights, 2 reverse lights, 1 blue LED, 1 orange LED (flames), 4 warning LEDs. By wiring 2 LEDs in parallel per pin, you can go up to 26 LEDs. Hardware

Question 4

Which Arduino for RC LEDs?

Accepted Answer

The Arduino Nano ESP32 is recommended: compact, built-in Bluetooth, Arduino IDE compatible. All other ESP32 boards (WROOM-32, S3 DevKit, C3) also work. The app automatically adapts to your board.

Question 5

Which ESP32 boards are compatible with Flare RC?

Accepted Answer

Several ESP32 boards are compatible with Flare RC, in 4 categories:✅ Tested and guaranteed:• ESP32-WROOM-32 (NodeMCU, DevKit V1, ELEGOO, AZDelivery, HiLetgo, etc.)🧪 In beta test:• ESP32-S3 (Arduino Nano ESP32 official, XIAO ESP32-S3, ESP32-S3 SuperMini)⚠️ Theoretically compatible, untested:• ESP32-C3 (SuperMini, DevKitM-1) — limited to ~8 LEDs❌ NOT compatible:• ESP32-S2 (no Bluetooth)• ESP32-P4 (no Bluetooth, no WiFi)• ESP32-H2 (no WiFi, specialized for Zigbee/Thread)• ESP32-C2 (not supported by standard Arduino IDE)The Flare RC app automatically adapts to your detected board.

Question 6

Can I put 2 LEDs on the same pin?

Accepted Answer

Yes, by wiring them in parallel. Important: you need one resistor per LED, not one shared. The limit is 40mA per ESP32 pin, so maximum 2 LEDs at 20mA each. Useful for bodies with dual headlights.

Question 7

Which resistor for the LEDs?

Accepted Answer

Two values are enough: 220 Ω for headlights, reverse lights and blue LED. 300 Ω for brake lights, orange LED and hazards. 330 Ω and 360 Ω values are also compatible.

Question 8

How to power the Arduino from the RC car?

Accepted Answer

Connect the receiver's BEC 6V to the ESP32 VIN pin, and connect the GNDs. No USB cable needed during operation. Important: always connect the receiver GND to the ESP32 GND, otherwise the RC signal will be erratic. App & Software

Question 9

How to calibrate the radio signal?

Accepted Answer

The app offers guided automatic calibration in 4 steps via Bluetooth: neutral → full forward → full reverse → dead zone. The app automatically detects errors (inverted signal, range too small) and suggests corrections.

Question 10

Is the app compatible with all RC radios?

Accepted Answer

Yes, the app is compatible with all radios using a standard PWM signal (1000-2000µs). Calibration allows adaptation to each radio, including inverted signals (full forward = low pw).

Question 11

How to update firmware without USB?

Accepted Answer

Firmware updates are done via USB cable and Arduino IDE on your PC or Mac. Plug in the ESP32, open your .ino file in Arduino IDE, select the correct board and port, then click the → arrow to upload. Your settings are preserved in flash memory. Features

Question 12

How do RC exhaust flames work?

Accepted Answer

Backfire has 5 combinable effects: classic sequence (blue→orange), pre-flame crackle, double détonation, release backfire with adjustable range and cycles, and fading afterburn glow. Everything configurable in the app without touching code.

Question 13

What is the US mode?

Accepted Answer

On American cars (muscle cars), rear lights serve as both brake lights and turn signals. Flare RC's US mode reproduces this behavior: rear lights blink during hazard AND illuminate brightly during braking.

Question 14

Can I change Pin pins from the app?

Accepted Answer

Yes! The Pins tab lets you reassign any Pin. Two options: send the config via Bluetooth (ESP32 saves and reboots), or generate a custom .ino file to flash. Useful if some pins are already in use on your setup.

Question 15

What happens if the radio signal is lost?

Accepted Answer

Flare RC includes an RC signal watchdog. If no valid signal is received for 5 seconds (car out of range, transmitter off), all LEDs start flashing rapidly to indicate signal loss. As soon as the signal returns, the LEDs automatically resume normal behavior. Fog, Light bar & CH3 (suspended)

Question 16

How to install fog lights on my RC car?

Accepted Answer

Connect 4 LEDs to pins G17/G18 (front) and G19/G20 (rear) with a 220 Ω resistor per LED. Front: white, ice blue or yellow. Rear: red only (regulations). Activate from the app or via your transmitter CH3 channel (suspended for now) connected to G36.

Question 17

How does the multifunction CH3 channel work? (suspended)

Accepted Answer

⚠️ Feature suspended for now. Connect your receiver CH3 signal wire to pin G36. In Settings → CH3 → Fog lights, configure the number of clicks per function: e.g. 1 click = fog lights, 2 clicks = light bar. The delay between clicks is adjustable (200-800ms) to avoid accidental triggers.

Question 18

How to install a light bar on an RC car?

Accepted Answer

1 red LED on G21, 1 blue LED on G22, each with a 220 Ω resistor. Recommended: 10000mcd+ high brightness LEDs for realistic effect. 4 sequences: alternating red/blue, double flash, rotation, sweep. Speed and intensity adjustable from app.

Question 19

Does night mode automatically reduce brightness?

Accepted Answer

Two options: Manual — a button in the app reduces global intensity by the chosen percentage (10% to 90%). Automatic — add an LDR sensor (photoresistor ~€1) connected to G36 with a 10kΩ resistor. Intensity reduces automatically when ambient light decreases. Sensitivity is adjustable.

Question 20

Can I create a custom light bar or chase?

Accepted Answer

Yes. Custom LED groups coordinate several LEDs into one sequence (red/blue alternation, rotation, chase…). You set the order, brightness and delay of each step; the group runs continuously, on a tap, or linked to a function (light bar, hazards).

Question 21

Do the light effects work without a phone?

Accepted Answer

Yes: once set up, everything runs on the ESP32 board. The Standalone mode even plays a light loop on its own (demo show) — it auto-starts on power-up and resumes after a cutoff, with no phone connected.

Question 22

Can I save several lighting setups?

Accepted Answer

Yes, with modes. Set your lighting as you like, save it under a name (race, pit, parade…) and reactivate it with one tap from the control panel. Each project keeps its own modes.

Question 23

Why disable the light bar when not in use?

Accepted Answer

The ESP32 has a limited number of PWM channels (16 on the WROOM board) — these allow LEDs to dim and fade (otherwise it's on/off only). Standard effects already use ~9, and the light bar uses 4 more when enabled. By leaving the light bar off when you don't use it, Flare RC automatically frees its 4 channels for your custom LEDs — which can then dim and fade instead of plain on/off. A custom LED with no PWM channel still works, but on/off only. Assembly & Wiring

Question 24

Which GPIO pins are forbidden for each ESP32 board?

Accepted Answer

List of pins to avoid for each board:• ESP32-WROOM-32: G6–G11 (QSPI flash), G34–G39 (input only).• ESP32-S3: G26–G32 (internal flash on WROOM-1), G33–G37 (PSRAM if present).• ESP32-C3: G11–G17 (internal flash), G18/G19 (USB D+/D-).The app auto-detects your board and only shows available pins in the Pins tab.

Question 25

Why do my LEDs flicker strangely at startup?

Accepted Answer

This is almost always a common GND issue. The ESP32 GND and the RC receiver GND must be connected together — as well as the cathodes (-) of all your LEDs. Use the GND rail (blue line) of your PCB universel to connect all these wires together. This is the number 1 beginner mistake.

Question 26

Can I put 2 LEDs on the same pin to save pins?

Accepted Answer

Yes, by connecting them in parallel — but with one resistor per LED, not one shared. Absolute limit: 40mA per ESP32 pin. With 20mA LEDs each, 2 per pin is the maximum. With 30mA LEDs, one per pin only. Exceed this limit and you risk permanently damaging your ESP32.

Question 27

How to protect the installation against moisture?

Accepted Answer

Apply electronic varnish (conformal coating) to solder joints and the ESP32. Allow 24 hours to dry. Avoid varnishing connectors and buttons. For a permanent installation, solder on a PCB rather than using a PCB universel — connections are more reliable and compact.

Question 28

Can I use a smaller ESP32 board for a compact build?

Accepted Answer

Yes! If you only use one or two functions (e.g. exhaust flames only, or light bar only), a mini ESP32 board is more than enough and takes up less space in the chassis. Important points: check that your BEC outputs 6V compatible with your board, and remember to customize the pins in the app's Pins tab as GPIO numbers vary between board models.

Question 29

How to simulate a dual exhaust?

Accepted Answer

No firmware modification needed! Wire 2 LEDs in parallel on the same pin: G2 for blue (one per exhaust) and G32 for orange. Each LED needs its own 220Ω resistor. Both LEDs will fire together like a real dual exhaust.

Question 30

Can I use a dual-color red/blue LED for the exhaust?

Accepted Answer

Yes, it's the perfect solution for the exhaust! A 5mm red/blue dual-color LED has two diodes in one package with 3 pins: blue anode (G2), red anode (G32), common cathode (GND). One hole in the body, both exhaust colors in one LED. Troubleshooting

Question 31

My throttle fluctuates at rest without touching the radio — what to do?

Accepted Answer

Most common cause: 2.4 GHz WiFi interference. Modern RC receivers (Futaba T-FHSS, Sanwa FH-S, Spektrum DSMR) use the same 2.4 GHz band as your WiFi router. If you test near a WiFi router, the surrounding radio noise saturates the receiver at rest. Solution: move at least 2-3 meters away from any WiFi router, or test outdoors. Other possible causes: faulty receiver, high-frequency competition ESC, poor common ground. See the full troubleshooting article.

Question 32

How to diagnose an unstable RC signal issue on ESP32?

Accepted Answer

Proceed step by step to isolate the noise source: 1) Plug a servo on CH2 — if it jitters, it's the radio/receiver. If stable, the source signal is good. 2) Test ESP32 alone on USB, without ESC or car — if stable, it's the ESC or environment. 3) Move away from any 2.4 GHz WiFi source (router, smartphone, microwave). 4) Check common ground between receiver and ESP32. 5) If the issue persists with a competition ESC, add an RC filter (100Ω + 10nF) between signal and GPIO.

Question 33

Why does 2.4 GHz WiFi disturb my RC receiver?

Accepted Answer

Modern RC radios (Futaba, Sanwa, Spektrum, KO Propo, Flysky) use the 2.4 GHz band — the exact same as home WiFi. A WiFi router transmits continuously at 100 to 1000 times higher power than your RC transmitter. At rest (neutral throttle), the bits of the received RC signal are at the critical threshold — WiFi noise is enough to flip the decoded value. Under command (full throttle/brake), the value is saturated and noise doesn't change anything. That's why the issue only appears at neutral.

Question 34

Do I need an RC filter between the receiver and ESP32?

Accepted Answer

In most cases, no — Flare RC includes a software filter (anti-glitch + median filter) that eliminates 90% of parasites. A hardware RC filter (resistor 100Ω or 220Ω in series + capacitor 10nF to GND, soldered close to the GPIO) is only useful in specific cases: very high-frequency competition ESC (Hobbywing XD10/XR10 Pro, Mamba X), noisy industrial setup, long signal cables. Cutoff frequency (~159 kHz with 100Ω/10nF) blocks parasites without altering the legitimate RC signal (50 Hz). Ready to start? Download Flare RC and transform your RC car in a few hours. Get it on Google Play

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