FAQ
TL;DR: 115200 baud works for flashing; "CCC..." means the bootloader is ready. For ELM327s using WinnerMicro W600-B800, this FAQ shows how to enter programming mode and sort out UART speed/AT control. [Elektroda, divadiow, post #21622696]
Why it matters: It helps owners fix "how do I enter W600 programming mode or speed up UART?" without bricking their OBD2 adapter.
Quick Facts
- UART mapping on W600 here: PA4/PA5 = UART0, PB11/12 = UART1. [Elektroda, divadiow, post #21623181]
- On this PCB, PB11/12 route to a PIC18F25K80 through resistors. [Elektroda, divadiow, post #21307394]
- Stock log shows SoftAP success at ~1.09 s and TCP on port 35000. [Elektroda, divadiow, post #21307244]
- Flashing third‑party firmware replaces stock and removes OBD2 functionality; no backup path reported. [Elektroda, divadiow, post #21307244]
- Flashing used 3.3 V power with common ground; 115200 baud default worked. [Elektroda, divadiow, post #21622696]
Which Wi‑Fi chipset is inside this ELM327 OBD2 reader?
The unit examined uses a WinnerMicro W600‑B800 Wi‑Fi SoC, confirmed by board photos and boot output. [Elektroda, divadiow, post #21307244]
Which MCU handles OBD2 and how is it wired to the W600?
A PIC18F25K80 handles OBD2. The W600’s UART1 (PB11/PB12) connects to the PIC through series resistors on this board. [Elektroda, divadiow, post #21307394]
How do I put the W600 into programming (flash) mode?
How-To: 1) Wire RX, TX, GND, 3.3 V (external PSU; common ground). 2) In the flasher, select the COM port, 115200 baud, open port, then click Download. 3) Power on the module or briefly pull RESET low; the tool starts when bootloader appears. "Continuous output of CCC... shows it's in flash mode." [Elektroda, divadiow, post #21622696]
What does bootloader mode look like on serial?
You’ll see repeating "CCC..." characters. That continuous stream indicates the W600 is in flash mode and the flasher can proceed. [Elektroda, divadiow, post #21622696]
Will flashing OpenW600 remove OBD2 functionality?
Yes. The author reported no way to back up the stock firmware and that flashing OpenW600 made the device unusable as an OBD2 reader. [Elektroda, divadiow, post #21307244]
Which UART should I use for AT commands or direct W600 debugging?
Use UART0 on PA4/PA5 test pads. PB11/PB12 are wired to the PIC, so they pass through to the OBD MCU, not directly to the W600. [Elektroda, divadiow, post #21307394]
My W600 ignores AT+ commands—what does that mean?
The stock firmware likely lacks an AT command server. One user confirmed, “does not respond to AT+.” Use UART0 or reflash firmware that exposes AT if needed. [Elektroda, kilowatov, post #21622850]
What baud rate should I use to flash the module?
115200 baud worked reliably during flashing. Open the port and start the download first, then power or reset the W600 so the flasher catches the bootloader. [Elektroda, divadiow, post #21622696]
What does the stock boot log reveal?
It initializes SPI flash and parameters, logs MAC, then brings up SoftAP around 1.09 s. It also opens a TCP socket on port 35000, indicating a Wi‑Fi‑to‑UART bridge role. [Elektroda, divadiow, post #21307244]
Can increasing UART speed improve ELM327 performance?
A user reported better behavior after raising the exchange speed. "Now it works very well ... increase the exchange speed." You must have firmware that accepts such configuration. [Elektroda, kilowatov, post #21622716]
Can I flash the PIC with alternative firmware?
Yes. A user flashed the PIC18F25K80 with DeepOBD firmware, indicating that modifying the PIC side is possible on these adapters. [Elektroda, kilowatov, post #21622703]
Can I replace the W600 with an ESP‑01?
One user prepared an ESP‑01 as a drop‑in replacement. Ensure 3.3 V operation, correct UART mapping, and firmware compatibility with the PIC and your app. [Elektroda, kilowatov, post #21622727]
Where can I find documentation and SDKs for W600?
See links shared in-thread for WinnerMicro SDK docs (EN/CN) and module references, which cover registers, UARTs, and flashing tools. [Elektroda, divadiow, post #21622840]
What PCB markings were observed on this ELM327 variant?
The board shows “V02-1_S 2017-09-28 Ver:1.2” and “V03WC_M_V1.1 2020-11-18,” which helps identify similar hardware. [Elektroda, divadiow, post #21307244]
