C6 ULP + EInk demo

This demo uses ULP core to control temperature sensor and e-ink display using I2C.

Used Peripherals + Protocols

• I2C: Communication with temperature && humidity and e-ink display
• ULP: Code that controls screen and sensor works on ULP core

Used devices

• ESP32C6 DevkitC
• BMP280 + AHT20 temperature, humidity and pressue sensor module
• Waveshare 1.9inch Segment E-Paper Module
• M5Stack VAMeter
• BS170 N channel mosfet

Connection Scheme

ESP32-C6	Screen	Sensor	VAMeter	BS170
3v3	VDD	VCC	OUT+	NONE
5	SDA	SDA	NONE	NONE
GND	NONE	GND	OUT-	S GATE
6	SCL	SCL	NONE	NONE
4	RST	NONE	NONE	NONE
5	BUSY	NONE	NONE	NONE
3	NONE	NONE	NONE	G GATE
NONE	GND	NONE	NONE	D GATE

Command to build

make -j distclean
./tools/configure.sh esp32c6-devkitc:nsh
kconfig-merge -m .config PATH_TO_EXAMPLE/c6_ulp_eink/configs/espressif &&
make olddefconfig -s -j
make -j bootloader && make ESPTOOL_BINDIR=./ -s -j
make download ESPTOOL_PORT=/dev/ttyUSB0 ESPTOOL_BAUD=921600 ESPTOOL_BINDIR=./

What Does it Do

When device boots up, it configures screen and sensor. After that sets the ULP code and then sleep. ULP core might wake up a bit late and throught that time screen shows all 0's. After ULP wakes up screen gets refreshed and then shows temperature and humidty value. After that LP-Core also sleeps and then wakes up to update values.

Current Consumption Checks

Testbench

• Jumper on ESP32C6 removed, after that 3v3 and ground lines connected to the VAMeter (also Joulescope).

Values

• Booting up: 19-23 mA
• Deep Sleep + ULP awake: 1 mA
• Screen Refresh: 2.3 - 2.5 mA
• Deep Sleep + ULP sleep: 48-60 uA