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README: remove external RTC support

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King Kévin 2017-10-09 17:57:24 +02:00
parent b95994027f
commit 937c9fd25c
1 changed files with 2 additions and 7 deletions
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README.md
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@ -4,7 +4,7 @@ The purpose is to have LEDs on the circumference of the clock to show the progre
For that you will need:
- a WS2812B RGB LEDs strip (long enough to go around the clock)
- a development board with a STM32F103 micro-controller equipped with a 32.768 kHz oscillator for the Real Time Clock (such as the [blue pill](https://wiki.cuvoodoo.info/doku.php?id=stm32f1xx#blue_pill)), or using a external [Maxim DS1307](https://www.maximintegrated.com/en/products/digital/real-time-clocks/DS1307.html) RTC module
- a development board with a STM32F103 micro-controller equipped with a 32.768 kHz oscillator for the Real Time Clock (such as the [blue pill](https://wiki.cuvoodoo.info/doku.php?id=stm32f1xx#blue_pill))
- a coin cell battery to keep the RTC running (optional)
- a GL5528 photo-resistor to adjust the LED brightness (optional)
- a DCF77 module to set and update the time automatically (salvaged from a radio controlled digital clock)
@ -32,8 +32,6 @@ The brain of this add-on is a [STM32 F1 series micro-controller](http://www.st.c
To keep track of the time a Real Time Clock (RTC) is used.
If the board includes a 32.768 kHz oscillator (such as a [blue pill](https://wiki.cuvoodoo.info/doku.php?id=stm32f1xx#blue_pill)) the micro-controller will use the internal RTC.
Otherwise connect an external [Maxim DS1307](https://www.maximintegrated.com/en/products/digital/real-time-clocks/DS1307.html) RTC module to the I2C port and set `EXTERNAL_RTC` in `main.c` to `true`.
Also connect the external RTC square wave output in order to have a sub-second time precision.
Connect a DCF77 module (e.g. salvaged from a radio controlled clock) to the micro-controller.
This will allow to automatically get precise time (at least in Europe) when booting.
@ -42,7 +40,7 @@ Alternatively set the time using serial over the USB port (providing the CDC ACM
Power the board using an external 5 V power supply (e.g. through the USB port).
This will power the micro-controller, and the LEDs (a single LED consumes more energy than the micro-controller).
To keep the correct time in case the main power supply gets disconnected optionally connect a 3 V coin battery on the VBAT pin for the internal RTC, or in the module for the external RTC.
To keep the correct time in case the main power supply gets disconnected optionally connect a 3 V coin battery on the VBAT pin for the internal RTC.
For the LEDs use a 1 meter LED strip with 60 red-green-blue WS2812B LEDs.
Tape the LED strip along the border/edge of the clock.
@ -83,9 +81,6 @@ Connect the peripherals the following way (STM32F10X signal; STM32F10X pin; peri
- USART1_TX; PA9; RX; UART RX; optional, same as over USB ACM
- USART1_RX; PA10; TX; UART TX; optional, same as over USB ACM
- I2C1_SDA; PB7; DS1307 SDA; SDA; optional, when using external RTC
- I2C1_SCL; PB6; DS1307 SCL; SCL; optional, when using external RTC
- TIM2_CH1_ETR; PA0; DS1307 SQ; square wave output; optional, when using external RTC
- ADC12_IN1; PA1; GL5528; photo-resistor + 1 kOhm to 3.3 V; without GL5528 photo-resistor connect to ground for highest brightness or Vcc for lowest brightness
- TIM3_CH3; PB0; PA5; SPI1_SCK; generated clock for WS2812B transmission
- SPI1_MISO; PA6; WS2812B DIN; DIN; WS2812B LED strip data stream