You can also combine ESP-IDF and Arduino if you still want to use Arduino APIs (except for Wire in your case). If the driver is still limiting you might want to try the ESP-IDF implementation of the I2C driver – start at and use code from the I2C example to get up and running. Give the I2C driver the biggest possible continuous buffer it can handle and if it writes it efficiently (only big setup functions at the beginning of a multi-byte tranmissions) it should increase performance significantly. BTW your chip supports 1000 kHz fast-mode plus at p.6 – default Wire frequency is 100kHZ.Īlso page 8 of the datasheet shows the "Writing to IS31F元741 (Automatic address increment) " which should be what you want and the way to go to overcome the driver-overhead. The Wire library seems to have some significant overhead in its drivers, looking at places like here and more importantly the I2C write functions and sub-calls like this, so 62 microseconds overhead between I2C transmissions doesn’t seem that absurd…Įven tClock(1000000) ( docs) won’t help much if the inter-write times are so big. I thought that this could be an issue that could be caused by task switching from FreeRTOS (I’m running this code on the Setup function) but lowering the freertos scheduler frequency didnt help. Using this IC, you can use only the SDA and SCL pins of your Arduino board to control up to 8 digital I/O ports. Is this an inherent problem with the Wire library? Should I use the original ESP I2C library? Code ESP32 and a PCF8574 expander example The PCF8574 is an 8 bits I/O port expander that uses the I2C protocol.
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I’ve hooked up my scope and captured some screenshots to made it easier to show what’s happening: I2CWriteByte(addr, i2cAddrbuffer, i2cCMDbuffer) I2cAddrbuffer = IS31F元741addrmap Īnd then sending the data over to the I2C bus using the wire library: for(int i = 0 i I am filling 2 buffers with data uint8_t i2cAddrbuffer How to Use DHT-22 Sensor - Arduino Tutorial: The DHT-22 (also named as AM2302). Compile and upload code to ESP32 board by clicking Upload button on Arduino IDE. Copy the above code and paste it to Arduino IDE. Click Install button to install LiquidCrystalI2C library. Enter as a separate line (without quotation marks). Type LiquidCrystal I2C on the search box, then look for the LiquidCrystalI2C library by Frank de Brabander. There you click on the small icon behind Additional Boards Manager URLs. The issue that I am facing is that for some reason there is a big delay between consecutive I2C transfers (write only) that is causing very poor refresh rate. In the Arduino IDE, go to File > Preferences. I’m interfacing an LED matrix using a matrix driver that communicates over I2C. I’ve been building a project using PlatformIO and the ESP32 on a custom board.#Esp32 arduino i2c example how to
#Esp32 arduino i2c example install