A while back I designed a couple circuit boards to use ESP32 Dev Kit V1 modules. Since I designed those boards, a confusing array of ESP32 NodeMCU-type modules have become available. Two problems, even if you don't need any special features of the new modules: 1 – the pinsouts are different between the modules and 2 – the spacing between the pin rows can change.
If you order from Amazon, ebay or various Chinese sites, the specs aren't well spelled out (like distance between the rows) and determining the pinout often depends on the accuracy of a fuzzy picture. Also, I'll only be assembling a few of the 10 boards I'm having made, trusting the modules from "The Happy Captain Company" may not be the same the next time I order the same part.
Any recommendations for specific ESP32 NodeMCU modules that are likely to be available for the foreseeable future with some trustworthy specs? I'm in the US, and I may need a lot of I/O, so mini-modules won't do.
I was going to suggest the same as Dana. EasyEDA have the ESP32(16MB) available,
Am I right in thinking that all the ESP development software uses the built in (ROM) bootloader and no additional firmware is needed? If so then building the module into your board seems the obvious solution.
That seems like a lot of extra effort – worth it if I were building many copies, but a run of ten boards is likely all I will need. There's also a lot of 'glue' on a NodeMCU that would need to be duplicated.
6PCS ESP32 NodeMCU Board Live Mini Kit for ESP32 WiFi Module Bluetooth Internet of Development Board Based ESP8266 Fully Functional with Pins for WeMos DIY Kit : Amazon.co.uk: Business, Industry & Science
MH-ET LIVE D1 mini ESP32 ESP-32 WiFi+Bluetooth Interne. Connectivity Technology Bluetooth, Wi-Fi, USB, WLAN, I2C, GPIO. Wireless Communication Standard Bluetooth, 802.11b. 100% compatible with Arudino IDE, Lua and Micropython, it shows robustness, versatility, and reliability in a wide variety...
Am I right in thinking that all the ESP development software uses the built in (ROM) bootloader and no additional firmware is needed? If so then building the module into your board seems the obvious solution.