Solved. I ran some integrity test on all the pins, and there's an internal short between two of them. I found a fresh, never-used module and it flashes OK.

Oh, I didn't realize the CDN wasn't letting you through. I've attached the circuit diagram to this post (so it's uploaded to the Espressif server). You should now be able to see it.

That link does not work Really? You must be getting rendered a different page than me; maybe forum moderation rules don't permit links unless approved and the Espressif team are absent during Chinese New Year. The link is: https://www.14core.com/wp-content/uploads/2017/04/ESP32-Flash-USB-UART-Wirin...

mikemoy wrote:Where is the image?

Do you mean the image of the circuit? If it's not displaying inline, it's available here.

I've been struggling to understand why my flashing circuit isn't working. It's a copy of the image below, but without the LED, and using a real 3.3V power supply. https://www.14core.com/wp-content/uploads/2017/04/ESP32-Flash-USB-UART-Wiring-Guide-diagram.jpg I know the module works, because I have s...

So, I assume not possible then? The STM32 ADC1 and ADC2 can be synchronized in dual mode at orders of magnitude of Msps with hardware triggering; whereas the ESP32 can't do any of that? It's disappointing.

I was reading the API docs for i2s_set_adc_mode: esp_err_t i2s_set_adc_mode(adc_unit_t adc_unit, adc1_channel_t adc_channel) The only acceptable adc_unit_t is ADC_UNIT_1 . ( ADC_UNIT_BOTH is "not supported yet"). Does this mean that the ESP32 ADCs are incapable of recording stereo signals or is ther...

I'm trying to do some signal processing on a steady-state cosine signal emitted by the DAC (whose memory buffer is fed using the I2S driver). I hence need to synchronize my reading from the ADC with the DAC signal so that I can calculate phase difference. Is there a way to synchronize the DAC and AD...

No, but you have a 240MHz processor at your disposal; there's very little stopping you from generating the waveform yourself. Despite this, the best I can get out of this loop is 120kHz square wave: while(1) { dac_output_voltage( DAC_EXAMPLE_CHANNEL, 0 ); dac_output_voltage( DAC_EXAMPLE_CHANNEL, 25...

I'm trying to do a little steady-state signal processing on a circuit, making use of the cosine waveform (CW) generator as per this repo . The code there doesn't actually allow me to retrieve the current CW value and so at the moment I have to do my own CW lookup table (costing CPU and memory). Is t...