Maker computing seemingly sits on top of three, somewhat unbalanced pillars. In one corner is the now venerable Arduino and any number of compatibles, clones, and spin-offs, in the other is the Raspberry Pi. But the third pillar, perhaps a bit more arguably, consists of boards based around the Espressif ESP8266 and ESP32 chips.
Not a single company but an architecture this time based around a family of chips, and a community. Because what these three pillars of the community share is just that, community. About and around them are active, vibrant, communities.
There are any number of boards based around the ESP32, as well as its little brother the ESP8266. It’s interesting to see how they have evolved from the simple breakout boards we saw when the chip was released back in 2015 to something a lot more robust, and the latest data point is the esp32MX-E from Modtronix Engineering, which will be raising soon on Crowd Supply.
The small 64.4 × 42 mm (2.54 × 1.65 inch) board is built around an off the shelf ESP-WROOM-32 module. However things get interesting after that, with three independent methods of powering the board; a USB-C connector, a 2.1 mm barrel connector, or via broken-out +V and GND pins, the board can be powered with a 4.5 to 16 V supply.
The on-board USB connector also provides a serial console, and allows you to program the board. The board is has both Wi-Fi, and Bluetooth, provided by the ESP32, as well as an Ethernet jack. The board also has a Micro SD card slot, along with a user addressable LED and button.
The ESP32 board is built around is a dual-core 32-bit Tensilica’s Xtensa LX6 micro-processor operating at either 160 or 240 MHz, with 4MB of SPI Flash, and 520KB of SRAM.
Capable of running a real-time operating system (RTOS) like Zephyr, it is often under-utilised when used in projects, many of which could happily be built on top of an much lower powered 8-bit processor.
However, in addition to the ESP32, and somewhat interestingly perhaps, the board also has a user-programmable STMicroelectronics STM32F030F4 micro-controller. This is a 32-bit Arm Cortex-M0 core operating at 48 MHz, with 256 KB of Flash and 32 KB of SRAM. This secondary processor is an I²C I/O expander handling the pins on the two expansion headers; the first with 2×7 pins, the other with 2×10 pins with programmable pull-up and pull-down resistors on most inputs, although not all of the pins are available when the SD card slot is in use.
The board will be released in two versions. While both will have the same configurations, on will have an operating range of 0° C to 85° C, while the second, an ‘industrial’ version, will be capable of operating at temperatures down to -40° C. With all the connectors facing towards one side, for easy access when in an enclosure, the use case for this ESP32-based board is really rather obvious.
The additional I/O capabilities mark this out as a cheap data logger. Aimed squarely towards the Internet of Things (IoT) and industry, this board is intended to be housed in anonymous black or grey boxes with numbers written in sharpie on the outside to let you tell it apart from the fifty other identical boxes you have scattered around your factory.
This board, and the others like it, are the quietly anonymous Windows XP boxes of the next decade, replacing ageing desktop machines that are ubiquitous on factory floors the world over.
With the addition of machine learning, this board is an obvious candidate for rapidly deployed distributed sensor network. It’s a leading indicator about how the market is shaping around computing that originated in the maker market.
In other words, the esp32MX-E is an excellent example of a whole class of boards I’m starting to see a lot more right now. While they have a network connected, it’s almost a given these days, they are relatively low powered and capable of being used as ‘smart’ sensors. Of running machine learning locally on the edge looking for noises or vibration that says that something is wrong with the ‘legacy’ dumb machines that the anonymous box has been velcroed to to on the factory floor.
While it’s not yet available you can the esp32MX-E will be raising soon on Crowd Supply, and you can sign up for email updates to be notified when the project goes live. While there isn’t an indicator of price, and won’t be until the Crowd Supply campaign starts, this board is an obvious example of what I call ‘capable computing,’ computing that is “good enough.”
I’m rather looking forward to getting my hands on a bunch of them, or at least something similar, and replacing some of the self-built smart things I have around the lab with some robust computing with a little bit extra head room to do more interesting things like machine learning.
UPDATE: The esp32MX-E is now live on Crowd Supply, with a single board costing $30 for the basic model with free shipping inside the US, or an extra $7 for worldwide shipping. The industrial version with temperature tolerance between -40°C and +85C adds an extra $2, while you can also pick up a prototype daughterboard along with the board for another $2. Ordering in larger volumes will get you some discount, with 5 basic model boards costing $139.