May 10, 2018

The Sparkfun ESP32 Thing in 2018

This has been laying in my drawer for over a year. I connected it up today to a USB cable and my linux system sees: 
May 10 16:28:49 cholla kernel: usb 2-1.8: new full-speed USB device number 5 using ehci-pci
May 10 16:28:49 cholla kernel: usb 2-1.8: New USB device found, idVendor=0403, idProduct=6015
May 10 16:28:49 cholla kernel: usb 2-1.8: New USB device strings: Mfr=1, Product=2, SerialNumber=3
May 10 16:28:49 cholla kernel: usb 2-1.8: Product: FT231X USB UART
May 10 16:28:49 cholla kernel: usb 2-1.8: Manufacturer: FTDI
May 10 16:28:49 cholla kernel: usb 2-1.8: SerialNumber: DN027NC4
May 10 16:28:49 cholla kernel: ftdi_sio 2-1.8:1.0: FTDI USB Serial Device converter detected
May 10 16:28:49 cholla kernel: usb 2-1.8: Detected FT-X
May 10 16:28:49 cholla kernel: usb 2-1.8: FTDI USB Serial Device converter now attached to ttyUSB0
I pull down an up-to-date copy of the IDF: 
git clone --recursive https://github.com/espressif/esp-idf.git
Inside here is our old friend, esptool.py, it needs the pyserial package, which is not installed on my linux system by default. 
dnf install pyserial
cd esp-idf/components/esptool_py/esptool
./esptool.py version
esptool.py v2.3.1
2.3.1
A simple command is to check my flash chip: 
./esptool.py flash_id
esptool.py v2.3.1
Connecting......
Detecting chip type... ESP32
Chip is ESP32D0WDQ6 (revision 0)
Features: WiFi, BT, Dual Core
Uploading stub...
Running stub...
Stub running...
Manufacturer: ef
Device: 4016
Detected flash size: 4MB
Hard resetting via RTS pin...

Clocks and clock speed

The Sparkfun thing has a 26 Mhz crystal for the CPU, and a 32768 Hz crystal for the RTC.

Both this board and my WeMOS boards have the D0WDQ6 chips. These are early production chips (reflecting the fact that I was eager and bought them in late 2016). The code D0WDQ6 indicates: 

D: Dual core
0: no internal flash
WD: WiFi+Dual-Mode Bluetooth
Q6: 6x6 QFN
I am reading conflicting information about whether this chip may be limited to 160 Mhz or can run at the full 240 Mhz clock speed. Apparently 80 Mhz is a minimum? Sparkfun indicates a 240 Mhz clock speed, so this is probably a needless worry.
Feedback? Questions? Drop me a line!

Tom's Computer Info / tom@mmto.org