MH32

This page discusses a number of MCUs that are expected to share the same or a closely related die.

Disclaimer: the following is speculation:

These microcontrollers are manufacturer by MegaHunt https://megahuntmicro.com/

MegaHunt is the OEM for a number of companies

Beijing Hongli Kunpeng International Trade Co., LTD.

Website: https://www.hlkpint.com

The site mentions they replace ST parts. The following parts are mentioned:

• HL2030A
• HL2103A
• MH2103C
• HL32F103A (in an image 'table')
• HL32F103C (in an image 'table')

It is assumed the F103A and 2103A are equivalent, as well as the F103C and 2103C. It is assumed the 2103 is a replacement for F1 series (Cortex M3). and the 2030 a replacement for F0 series, as it has a Cortex M0 core. So far the 2103 has been observed.

The datasheets provided for these parts contain a disclaimer mentioning MegaHunt, therefore it has been established MegaHunt is related to these parts.

LuatOS

Website: https://wiki.luatos.org/

LuatOS offers a series of AIR32F103 microcontrollers, variants with different amounts of flash and pins are available. Mentions of the following variants are made:

• AIR32F103CBT6
• AIR32F103CCT6
• AIR32F103RPT6
• AIR32F103VET6
• AIR32F103VGT6
• AIR32F103ZET6

Availability:

No official distributors known.

There appear to be little resellers on AliExpress in 2026. I have located one: https://nl.aliexpress.com/item/1005009166472987.html

On an LuatOS Air32F103 board:

These boards were available for a while, but appear to be no longer available.

On a Blue Pill:

https://nl.aliexpress.com/item/32719680030.html Select option "STM32F103C8T6 china" In February 2023 the board received contained what appears to be a relabelled AIR32F103, which likely is an MH2103A.

WIZNet https://wiznet.io

WIZNet, the creator of the W5500 Ethernet controller, has created a microcontroller with an integrated ethernet controller. Amongst others, there is the WH55MH32 ( https://wiznet.io/products/mcu-chips/w55mh32 ) which appears to be a MegaHunt core. The part name containing MH32 also suggest this.

No known distributors.

WIZNet Evaluation Board: W55MH32Q-EVB https://nl.aliexpress.com/item/1005010531068787.html

TODO: rewrite below

There are various git repositories floating around on github for the air32f103, mh32f103 and mh2103c, mentioning the parts are equivalent.

These chips are reported to have additional RAM (96 KiB) that can be unlocked by some magic bytes. Additionally they can run much faster (up to 218 MHz). Furthermore they offer a random number generator and a dac.

In a migration guide it discusses a way to identify the MCU. It seems their serial number starts with a fixed value. The migration guide discusses

MH2103C CBT6   0x1C5A5BBX
MH2103C CCT6   0x1C5A5CCX

The LuatOS wiki mentions the following values

AIR32F103CBT6 0x1A5A5BBX
AIR32F103CCT6 0x1A5A5CCX
AIR32F103RPT6 0x1A6A5CDX
AIR32F103VET6 0x1A8A6DDX
AIR32F103VGT6 0x1A8A6EDX
AIR32F103ZET6 0x1A9A6DDX

Observed values are

AIR32F103   0x1a5a5bb5
 MH32F103   0x1a5a5cca

The fist byte in the migration guide is 1C. Observed on the tested MCU it is 1A. This suggests these are equivalent to HL2103A in stead, furthermore we see the BB and CC near the end, suggesting a 128 KiB flash and a 256 KiB flash variant.

There have some issues as discussed in a previous blog post (TODO link)