An Alternative to the Blue Pill?

An ATtiny88-Based Replacement for the STM32-Based Blue Pill

Alasdair Allan
3 min readApr 10, 2019

The ubiquitous STM32-based Blue Pill board is everywhere. It’s not popular, or particularly easy to use, but it’s cheap enough to be practically free in quantity, and readily available. It’s a poster child for capable computing.

However, we all know the Blue Pill has problems.

People often get intermittent results with the board due to the persistently reoccurring R10 problem. While most of the boards work okay, despite the commonly occurring resistor mismatch, I’ve seen some with a 10GΩ resistor in R10 rather than the more common (and still wrong) 10kΩ or 4.710kΩ resistors. I have no idea what’s going on when they’re put together, maybe the spec sheet floating around Shenzhen is a badly multiply-photocopied thing and the value of the R10 resistor just isn’t that clear?

So it’s actually sort of interesting to see a potential replacement being sold into the same niche as the Blue Pill. However rather oddly perhaps the board, called the MH-Tiny produced by MH-ET Live, is based around the ATtiny88.

The MH-ET Live MH-Tiny board. (📷: MH-ET Live)

Unlike the STM32, which is a 32-bit Arm Cortex-M3, the significantly less powerful ATtiny88 is an 8-bit AVR processor. The board breaks out 26 GPIO pins, although like the Arduino Uno two of these are double up for USB serial communications. All the pins are capable of PWM, yet only two have hardware PWM support, while there is ADC support on eights of the pins.

Pin out for the MH-ET Live MH-Tiny board. (📷: MH-ET Live)

The MH-Tiny is programmable using the Arduino development environment, and a walkthrough of how to get started is available on the board’s website.

The MH-ET Live MH-Tiny board, front (top) and back (bottom). (📷: MH-ET Live)

The MH-Tiny is available on AliExpress starting from around $1.70 a piece in low volumes. That’s comparable with the STM32-based Blue Pill, and of course the equally ubiquitous but much higher powered ESP8266 and Air 602 modules. But since the board is based around an 8-bit AVR, rather than a 32-bit Arm, you’re getting a lot less computing power for your money.

Perhaps a case of Moore’s Law catching up with hardware? Unless you have a specific need for an AVR-based board, there are more powerful alternatives.