Graupner MZ-32 Teardown

Description

I decided to gently take apart the Graupner MZ-32 R/C Transmitter, taking apart just enough to identify all of the main electronic components. I didn't completely remove all of the smaller PCBs, as it didn't seem necessary to identify some of the less important interface ICs and associated switches, etc.

This transmitter was well engineered and the design was well thought out. Graupner did a nice job laying out their PCBS, and routing components on both sides. There is no evidence of any cheap components being used or leaving out components in order to reduce cost.

The dual-processor design was a smart engineering decision, leaving the RF and LCD parts of the Tx to be two separate domains, each controlled by their own STM32 processor. Therefore, there is no overhead on the RF module being wasted to any LCD and associated code.

The Wifi, Bluetooth, and MP3 are nice simple SOC modules that are easy to integrate into an embedded system. So much future potential!

Details

Ok, so here are the basic components of this Graupner MZ-32 R/C Transmitter, which was released around first quarter of 2018.

Main components list:

STM32F4229Z
STM32F405
480272HG-T32
IS42S16400J

MT28EW256ABA

AM 480272HG-T32
ESP-12S
W32i-A
VS1011E

Processor 1:

STM32F4229Z -> ST Micro STM32F29, LQFP-144 pin package (ARM Core). The 32F29 has the built-in LCD-TFT controller, which is what they are using as their processor to drive the touch screen, graphics, etc.

Processor 2:

STM32F405 ->ST Micro STM32F405, LQFP-64 pin package (ARM Core). The 32F405 is part of their ST32 family, which is what they are using as their main RF processor, handing all the actual Tx/Rx processing.

Memory 1:

ISSI IS42S16400J -> Integrated Silicon Solutions IS42S16400, 8MB (64 Mbits) SDRAM, external 8MB memory added on for the Processor 1, LCD processor.

Flash 1:

28EW256ABA -> Micron NOR Flash, 32MB (256 Mbits) 56-pin TSOP. This flash provides an external 32MB to the main lcd processor (processor 1).

LCD:

AMPIRE 480272HG-T32 -> Ampire 480x272 RGB LCD screen with capactive touch, parallel interface. This is the main Tx LCD interface with touch.

WiFi Module:

ESP-12S -> RF Solutions 2.4Ghz wifi module. This is the wifi SOC module that provides the 2.4Ghz wifi capability for this Tx.

Bluetooth Module:

W32i-A -> Silicon Labs Bluetooth SOC module. This unit provides the bluetooth capability for this Tx.

MP3:

VLSI VS1011E -> VLSI Solutions MP3 SOC Module. This unit provides the mp3 decoding capability for this Tx.

(The 8MB SDRAM is mainly used for the LCD Frame Buffer needed for the STM32F429, as there is no internal ram available on these STM processors big enough for an LCD frame buffer. )

** Just to re-iterate, this Tx design is top-notch, and was well thought out and engineered to very high standards, and not cutting any corners to save costs.

The Dual-processor design gives them so much capability to keep RF comms and GUI/User operational tasks in separate domains.

There is plenty of room for the future in this design, as they have plenty of flash space in both STM32 processors, as well as the external 32MB flash for the main processor. Also, they may have even more external SDRAM available for the main processor, depending on how much of the 8MB SDRAM they are using for the frame buffer (or buffers).

Project Logs

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Debug Header (SWD)

PhillyFlyers • 04/13/2020 at 21:39 • 0 comments

5-pin header on the main board, goes right to the main STM32F429ZI processor... utilizing the Serial-Wire Debug interface from the chip.

** Note: ** developers enabled the 'read protection', so can't easily dump the main flash of the chip to capture the main firmware, not sure how this firmware in the cpu's 2MB flash releates to the FW update files.. but would have been nice to try and understand the correlation.