STCmicro Development Boards

Temu STC89C52 Kit

Overview

I saw on Temu a '51/52 MCU Development Board for Learning KIT STC89C52 Experiment Board' for sale, a microcontroller (MCU) kit you build yourself featuring a STCmicro STC89C52 MCU and various inputs and outputs. Note that the STC89C51 is used in various Temu electronic kit products.

Temu claimed the RRP to be £75.20 ($98.91) but they were selling it for £15 ($19.73). That might seem like a steal but there is always a concern about getting hold of documentation so I waited for it to drop in price. Which it eventually did, when I bought it I paid  £11.86 ($15.62) although it dropped after buying it, allowing me to claim back £2.51 ($3.30).

As typical with Temu products the user manual does not contain anything specific or useful to the kit, such as build instructions. However, the Temu page contained this description:

This development board features 17 separate modules, which include a power USB to serial port, a buzzer, DC motor driver, stepper motor driver, LCD12864 display interface, LCD1602 display interface, relay, ISP download socket, reset circuit, an 8 * 8 matrix keyboard, 1 * 4 independent buttons, infrared transmitter, infrared receiver, DS18B20 interface, and a digital tube.

This electronic kit requires assembly and is not a complete product. You can find comprehensive instructions by scanning the QR code included in the package. For any inquiries, please reach out to us for expert assistance.

This DIY soldering kit is designed to help you grasp the fundamentals of printed circuit boards, familiarize yourself with different electronic components, and enjoyably practice soldering skills with your children, students, or fellow DIY enthusiasts.

The clearly marked connections on the board simplify the assembly process. You can use the labels on the PCB to solder each part. If it doesn't function after soldering, reach out to us for assistance. Please consult the User Manual prior to installation.

Taken from one of the images on the page are some of the board's features, which I'll now list with my notes in parentheses:

LCD1602 (likely supports attaching a 16 x 2 HD44780 display, not included)
LCD12864 (possible for attaching 128 x 64 graphics display, not included. I don't know the interface type)
Backlight adjustment potentiometer
Digital tubes (4 digit LED 7-segment display)
Flowing light (8 red LEDs in a row; 4 red, 2 green, 2 yellow)
Infrared emission (looks to be infrared LED)
MCU socket (ZIF socket)
4 * 4 matrix (16 push buttons arranged 4 x 4 forming a keypad)
Independent button (4 push buttons)
Infrared reception (photodiode)
Temperature sensor (3-way header to plug in sensor, not included)
Crystal oscillator
ISP Download Stand (5 x 2 male header for programming)
Relay
Buzzer
Stepping motor (5-way male header for stepper motor)
DC motor (2-way male header for motor)
Power switch
CH340G (USB to serial chip)
5V power supply (female barrel jack)
USB download dock (USB Type-B female connector)

Another image also lists features, again I’ve added my notes:

8X8 lattice (if this is referring to the keypad it should be 4 x 4)
8-bit Patch (likely the 8 LEDs in a row)
LDE light (have no idea)
On Board 9 Chips (should be the chip total but there are only 3 chips)
Infrared Remote Control (could be referring to the photodiode or infrared LED)
18B20 (support for DS18B20 temperature sensor)
Wireless Module Interface (the only wireless is the infrared?)
138 Decoder (could be a 74LS138)
Clock DS1302 (Real time clock, don’t know where that would be connected)
AD/DA (Analog-to-digital/Digital-to-analog converter, don’t know how that’s provided)
Stepper Motor Drive

I haven't linked to the Temu page as Temu tends to discontinue their products but I found a similar one on Amazon (not a sponsored link):

https://www.amazon.co.uk/STC89C52-Development-Learning-LCD1602-Controller/dp/B0BQ72G5H6

It's selling for £24.99 ($33.74) and has some differences, including an LED dot matrix, micro USB, and 2.4G wireless interface, and comes with a number of accessories including a remote control, LCD module, and motor. It looks to be a pre-assembled kit.

Technical

Searching online for STC89C52 we can find the datasheet:

https://www.stcmicro.com/datasheet/STC89C51RC-en.pdf

Which covers the STC89Cxx and STC89LExx series. We can see the MCU series is made by STCmicro (STC MCU), which is a Chinese manufacturer. The MCU is based on the 8-bit 80C51 MCU and features 64KB flash memory for the user’s program, supports In-System Programming (ISP) and In-Application-Programming (IAP), has different speed modes, and other features not found on a standard 80C51.

The STC89C series in particular runs on 3.3V to 5.5V, runs at maximum 48MHz, it also has various timers and input/output (I/O). On the last page of the datasheet we can see the specifics of the STC89C52:

8KB flash

512B SRAM

3 timers

1 UART (Universal Asynchronous Receiver-Transmitter)

2 DTPR (probably meant to be DPTR, Data Pointer register)

WDT (Watchdog timer)

4KB EEPROM

Internal low voltage interrupt

4 external interrupts which can wake up

Please read the full datasheet for the complete details.

I also found this page with a similar kit, which is worth a read:

https://hackaday.io/project/170540-adventures-with-a-stc89c52-development-board

Unboxing

The following information is based on what I received and may be different to what someone else may get.

The box was bashed and on the box it stated:

Product name: Programming Kit
Model number: H054
FCC ID:2AHMR-ESP32-S
Serial number: TF133

Along with a barcode having number '# 50875089230'.

Clearly the FCC ID is wrong and if you google it you’ll find:

https://fcc.report/FCC-ID/2AHMR-ESP32S

Which, not surprisingly, is for an ESP32 module.

The serial number, however, matches the sticker on the back of the PCB but googling the barcode number didn't come up with anything related.

In the box was a label with generic information, the unpopulated PCB, a bag of loose components, and the main chip, a red LED, and LED display protected with foam (not the usual anti-static type) but the ZIF socket was unportected and arrived with two bent pins as did other components too. Note that they didn't put static sensitive components in an anti-static bag and there was no QR code so I was unable to get the assembly instructions. However, the components are labelled on the PCB with some Chinese that will need translating.

Here is a photo of the kit with the components taken out of the box and bag:

To confirm all the components were present I put together a list (see below) and used the photos from the Temu page showing the kit unassembled and assembled as a guide, however, the photos were poor quality and the two images of the kit unassembled had some differences.

Here is the list of the components I received, which I sorted by quantity, along with notes:

Construction

To be added soon.

All content of this and related pages is copyright (c) James S. 2026