Hardware
21.04.2020 17:54 by chris
- The ESP32 is a general purpose microcontroller from espressif, which is cheap (my board costs ~10€) and has a low power consumption.
- It is Arduino compatible, so it can be programmed using the Arduino platform tools, which a lot of people are used to. On the other hand, there is the ESP-IDF, which is a device specific framework from espressif under MIT-license. With this framework all device specific quirks can be used, but therefore it is not compatible with other microcontrollers.
- It comes with integrated WiFi und Bluetooth capability, which made it’s predeseccor, the ESP8266, quite popular.
- Supports UART, I²C, SPI, I2S, PWM, SDIO, ADC, DAC
- Links: datasheet, pinout
- The Bosch GY-BME280 is a digital barometric pressure sensor. It has a compact design and runs with 1.2V … 3.6V so it’s a good fit for the ESP (3.3 V).
- It operates between 300 … 1100 hPa and -40 … 85 °C.
- It can be connected using a I²C or a SPI bus.
- Links: product website, datasheet
1,77” ST7735S TFT color display
- 1,77 inch (~4,5 cm) color display with 128×160 pixels
- Very cheap (~8€)
- SPI bus
- The display is supported by several libraries like ucgib and ESP32_TFT_library.
- I first tried to supply a HAL for ucglib, since it is implemented on the Arduino framework and not the ESP-IDF, but then experienced very bad performance. Therefore I tried the ESP32_TFT_library (ESP-IDF version 4 fork by jeremyjh). This library uses a custom made SPI driver for the ESP32 and is a lot faster than my custom made HAL.
- Links: product website, datasheet
5V 0.5A USB power adapter