I've built a few ESP32 client & personal packaged projects using both the 30pin carrier level and the SMD WROOM module on either THT solderable prototyping board or a custom PCB. The former tends to be bulky and is overkill and messy when you need a few I2C/SPI peripherals (on THT-breakout boards) but not many GPIO while the latter is far more robust/reliable for multiple boards but expensive/time consuming for a 1-off. What I'd really like is a PCB laid out for the WROOM module with a THT-area and footprints for a few SOIC devices, maybe a dedicated ADC (the ESP32 on-board ADC is rubbish). So far the only thing that comes close is this one from directnine, but at 38GBP its very expensive for what I have in mind and is really only THT-compatible.

Does anyone have another similar off-the-shelf product suggestion?

I'm considering designing one myself. What would you put on there? As said, I'm thinking:

• the ESP32 WROOM module plus pins for external programming adapter (though I use OTA programming almost exclusively now)
• a few SOIC 8/14/16/20 'strips' with some SMD RC footprints for standard dual/quad opamp layouts
• a dedicated ADC and EXT reference with some SMD RC filtering
• space for a low wattage DC/DC or AC/DC converter?
• fits a standard 100 x 60 x 25mm prototyping enclosure?

Your thoughts?

 

So, I have been looking for protoboards that can be used with SMDs. So far this company’s products seem the most promising but they are very expensive. I point these out because of the pad design which might be helpful in laying out your proposed board.

​

 

Thinking about it, you might also want footprints for:

Type-C connector for power and data

The few components you’d need to include LiIon battery power/charge with a two pin JST connector to make standard LiPo cells plug-and-play.

A SMA or IPX antenna connector and a 50Ω transmission line to it.

A header for GPIO (2.45mm would be easy for some things, but there are some really nice, low profile and very small options as well)

 

Type-C connector for power and data - for power maybe. Adding data requires the CP2102 or CH340 chips and I've been trying to avoid putting them on board and only using an external USB/UART if necessary, but OTA mainly.

The few components you’d need to include LiIon battery power/charge with a two pin JST connector to make standard LiPo cells plug-and-play. - yes, that might be worth having on-board, not necessarily populated

A SMA or IPX antenna connector and a 50Ω transmission line to it - no, the WROOM module comes with a PCB antenna or an SMA connector - so if you need external antenna use the right module

A header for GPIO (2.45mm would be easy for some things, but there are some really nice, low profile and very small options as well) - an THT header area might be useful.

 

I have two suggestions.

1) For one-off SMD with simple circuit, I do double sided copper laminate and cut solder islands with an X-acto knife.

2) For a GP development board, it is difficult to anticipate all future needs. I would suggest laying out your own PCB to suit your immediate needs with additional pads to GPIO pins, an area of SMD pads, and some SOIC footprints.

 

A DIY design is IMO the best option. A four layer PCB stack from one of the cheap PCB houses is usually what I do during the design phase as you will need at least one PCB revision usually on a fresh design. Fully utilize both sides of the PCB so you can have extra space to solder on parts and to have easy access to PCB test-points.

Design example: https://forum.allaboutcircuits.com/...controller-and-sensor-node-for-canbus.189388/
This is the vref for the internal ADC that actually works to spec. https://www.analog.com/en/products/max6126.html#product-overview

https://github.com/espressif/esp-idf/issues/164
I agree, the ESP32 on-board ADC is total rubbish. The ADS1115 is a common external ADC for the controller.

You also might consider adding pads for a accelerometer. These things are pretty cheap and can easily provide movement/orientation information to a project.