ULP-I2C
Posted: Fri Oct 06, 2017 6:10 pm
Hi!
I just started with the esp32. I wanted to use an extern 16-bit ADC with the ESP. And I also intended to read that ADC with the ULP. As the ULP supports I2C I thought it was no problem.
Now I studied the Technical Reference Manuell and read about the RTC_I2C Controller. Apparently the I2C interface of the ULP is very limited. With the given I2C instruction I can only read one byte from the ADC before sending the STOP conditions. The 16-bit ADC I saw so far, required to read both bytes without a stop condition in between. So it is somehow possible to send an ACK instead of a STOP after reading one byte with ULP to receive the second half of my 16-bit Value. Or does someone know an 16-bit ADC where I can address the data bytes individually?
Well I can still fallback on the internal ADC but any other suggestions are welcome.
Greetings barosu
I just started with the esp32. I wanted to use an extern 16-bit ADC with the ESP. And I also intended to read that ADC with the ULP. As the ULP supports I2C I thought it was no problem.
Now I studied the Technical Reference Manuell and read about the RTC_I2C Controller. Apparently the I2C interface of the ULP is very limited. With the given I2C instruction I can only read one byte from the ADC before sending the STOP conditions. The 16-bit ADC I saw so far, required to read both bytes without a stop condition in between. So it is somehow possible to send an ACK instead of a STOP after reading one byte with ULP to receive the second half of my 16-bit Value. Or does someone know an 16-bit ADC where I can address the data bytes individually?
Well I can still fallback on the internal ADC but any other suggestions are welcome.
Greetings barosu