From 37e9e4b040967c2cc856905b63cfcc6e8e12c329 Mon Sep 17 00:00:00 2001 From: Maurice Makaay Date: Thu, 29 Apr 2021 10:30:52 +0200 Subject: [PATCH] Added hints about using 3.3V for serial to USB. --- doc/flashing.md | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/doc/flashing.md b/doc/flashing.md index b4ea27f..b5f0175 100644 --- a/doc/flashing.md +++ b/doc/flashing.md @@ -24,7 +24,7 @@ warranty. Perhaps you will destroy your lamp and your computer. * Allen key (2mm, 5/64") or torx (T8) screw driver * Soldering Iron -* A serial to USB adapter (FTDI) +* A serial to USB adapter (for example FTDI) that can provide 3.3V RX/TX signals * Some wires * Optional: sticky tape, hot glue gun, magnifying glass @@ -93,13 +93,19 @@ A few tips: ## Connect the wires to your serial to USB adapter +Make sure that your adapter uses 3.3V for the pns that you will connect to the lamp. +Some of these adapters allow you to switch between 3.3V and 5V using a switch or a jumper. +Do not use an adapter that only provides 5V output. Reason for this, is that the ESP32 chip +works at 3.3V. I have seen the chips accept 5V serial input, but I am not sure if they are +actually 5V tolerant. Better safe than sorry in such case! + The wires must be connected as follows: | Soldering point| Serial USB Adapter name | | -------------- |:------------------------:| | GND | GND | | TX | RX | - | RX | TX | + | RX | TX (3.3V) | | GPIO0 | GND | To be able to flash the lamp, `GPIO0` must be connected to ground while the lamp boots up.