From 4cfef2e8e9316ca52f94928a08d10ae86b08ddf6 Mon Sep 17 00:00:00 2001 From: Nathaniel Wesley Filardo Date: Thu, 26 Dec 2019 00:46:46 +0000 Subject: [PATCH] README: more hardware details --- README.rst | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/README.rst b/README.rst index 52c8c85..f85d4d6 100644 --- a/README.rst +++ b/README.rst @@ -57,18 +57,21 @@ ESP8266, etc. Revision 1.1 ============ -An AND gate (actually, a 7408) was added to gate serial access to the -WS2812. On boot, the ESP8266 emits debugging information to its alternate -serial console, which is also the ws2812 data source. This results in some -blindingly bright light when the machine boots or crashes. The AND gate -effectively prevents the chip from writing to the ws2812 matrix unless -another GPIO is pulled high as well. +An AND gate (actually, a 7408) was added to gate serial access to the WS2812. +On boot, the ESP8266 emits debugging information to its alternate serial +console, which is also the ws2812 data source (ESP GPIO 2). This results in +some blindingly bright light when the machine boots or crashes. The AND gate +effectively prevents the chip from writing to the ws2812 matrix unless another +GPIO (specifically, ESP GPIO 0) is pulled high as well. The WS2812 LED array from AdaFruit allows for one of many pins to be selected for the WS2812 input line; as the ESP8266 does not use all of the possible I/O lines of the Feather design, a free signal (N/C to the ESP8266 Feather Huzzah CPU board) was chosen instead and the AND gate's output -routed back into the stack on this line. +routed back into the stack on this line. We used the Feather pin immediately +below ADC; that is, the 6th pin from RST to convey this gated signal; on the +Feather NeoPixel board, this is selected by the jumper that sits below and +between the "e" and "a" in the big "feather" silkscreen. ESP IO ###### @@ -78,7 +81,7 @@ The various boards are interfaced as follows: +--------------+----------------------------------------------------------+ | ESP GPIO Pin | Function | +--------------+----------------------------------------------------------+ -| 0 | WS2812 AND-gate input (see above) | +| 0 | WS2812 AND-gate input (see Revision 1.1, above) | +--------------+----------------------------------------------------------+ | 2 | WS2812 serial shift out (to LED array input) | +--------------+----------------------------------------------------------+ -- 2.50.1