Maker IoT Idea's Espressif ESP12-E Card and Base Board Evoke Memories of the Altair Bus
Designed to connect peripheral cards with a microcontroller card — starting with an ESP-12 model — this modular kit draws from history.
Pseudonymous electronics designer "Maker IoT Ideas" is bringing back a classic computing form-factor, popularized by the Altair 8800, for microcontrollers, with an Espressif ESP8266-12E plug-in card and base board carrier.
"Originally started in May 2022, I wanted an interchangeable MCU [Microcontroller Unit] card based on ESP32/ESP8266 and eventually maybe an Arduino or [Raspberry Pi] RP2040 that can plug into a standardized base board, similar to a standard desktop PC motherboard, with standardized slots to add or remove peripherals as needed," the person behind Maker IoT Ideas explains. "This is now finally starting to come together."
While Maker describes the project as being inspired by a desktop PC motherboard, in reality it's closer to the design of the Altair Bus — later S100 Bus, having been co-opted by competitors — with a series of electronic cards that connect to a single shared central bus. While many of these cards hold peripheral devices, one or more will also host the central processing unit — which, in this case, is an Espressif ESP-12E ESP8266 microcontroller module.
"The ESP-12E Card contains the bare minimum components to allow the chip to function," Maker explains. "There are no power regulators or USB-to-TTL converters onboard. Code is flashed via an external USB-to-TTL converter, with flash and reset buttons on the actual PCB or available in the 2×20 Pin female header at the bottom of the card. Most of the GPIO [General-Purpose Input/Output] is also broken out to the 2×20 pin header, with the exception of the six GPIO that is usually connected to the internal flash on the ESP-12E module."
That 2×20-pin header is designed for connection to the base board, that then provides connectivity to the rest of the cards in the system — which could range from USB interfaces to make programming easier to storage, sensors, displays, and more. For now, though, Maker has developed a prototype limited to I2C connectivity along with two interrupt pins per slot — and, at the time of writing, had not shared designs for any peripheral cards.
More information on the project is available on Maker's Hackaday.io pages for the ESP-12E Card and the Base Board respectively.