ESP32 C3FN4 not detecting

[shastrinvs]

Hi

We have designed a board using ESP32-C3FN4

We are not able to detect the chip. We have provided EPSON 40MHZ crystal [FA-238].

The hardware guide for ESP32 C3 mentions that we have to choose a component in series with XTAL P pin, but does not recommend any value.

Also there is a 499ohm in series with UOTXD in the ref schematic.

Need help of experts to solve this.

Hardware connection to the ESP32 C3FN4

ESP UART -- FTDI UART

U0TXD - RX
U0RXD - TX
GND - GND
IO0 - GPIO9
RST - EN


Best Regards

[ESP_Sprite]

- What do you use as a 3.3V power source?
- Can you confirm the reset signal is OK? (Pulled low at startup, then high afterwards)
- Does your 40MHz crystal oscillate? Measure it with an oscilloscope, you should see a 40MHz low-ish amplitude sine on one of the pins.
- Do you see bootup chatter on the Tx0 pin when you reset the ESP?

[shastrinvs]

Hi

I use a LDO as a power source. 3.3V is stable

I think the issue is with GPIO8 and GPIO2 not be pulled up with 10K to 3.3V, as i have connected it to an LED.

As per ESP32 C3 TRM, page 182, Table 7-2, GPIO8 and GPIO2 states should be high when the device is booting out of reset.

Will try this assumption and keep you posted.

BR

shastrinvs