FlexCase E & G

Supported OS’s

The FlexCase MPU implementation is designed to closely mimic the architecture of the manufacturer’s official development kits. As such, you should be able to flash any approved OS image from the manufacturer and expect it to function correctly.

If you are uncertain about which hardware features are connected, please reference the MPU pinout/data sheet to confirm the available interfaces. In general, most operating systems will be compatible, and your choice will depend on your application needs (e.g., if you require a GUI or specific kernel).

Identifying the MPU

There are a few ways to identify exactly which MPU module is installed in your FlexCase:

• Recommended (Newer Models): Look for the label on the back of the device for the microprocessor short code (CMxx). This code can be referenced against the complete list in the microprocessor pin out/data sheet documentation.
• Purchasing Documentation: You can reference your original purchasing documentation or receipt.
• Direct Inspection: If the case is open, you can look at the MPU module itself. The processor model is typically marked on the silk screen of the module.

Process Lookup

In order to use the header flashing method, you must have both a supported FlexCase and Module.

Flashing through header brackets (new)

This process utilizes dedicated programming headers for flashing, offering a streamlined approach that does not require opening the case.

Compatibility and Control:

• This process is only available on some models of the FlexCase and MPU. Please check the table above (on the original page) for compatibility.
• The control scheme for the MPU_Boot and MPU Reset pins is available on the data sheet pin out.
• If you are looking for an automated program that you can flash to your microcontroller to initiate a programming process, you can check the download site or reach out to us to provide a file for them.

Process Steps:

1. Ensure the FlexCase is unpowered and the OS image is compatible with the MPU you are using.
2. Connect the header USB to a host PC. DO NOT CONNECT V+; connect only D+, D-, and GND.
3. Turn on the FlexCase.
4. Set the “MPU_Boot” pin High on the MCU.
5. Toggle the “MPU Reset” pin HIGH and then LOW to reset the MPU.

The MPU will now be connected to the host PC in MASKROM mode. You can flash the OS using the desired tool following the MPU manufacturer’s guidelines (typically RKDevTool or Raspberry Pi Imager).

Flashing via the PCB (old)

This is the older process, and in order to flash the MPU, you’ll need to have the case open to access the internal PCB connections. There is a similar Micro USB port available on the PCB for this purpose.

The hardware is implemented similar to how most Compute Module (CM) development boards are designed, allowing a direct connection for OS flashing.

Process for MASKROM Mode:

1. To put the MPU into MASKROM mode, simply insert a USB connection to the designated port on the PCB and apply power to the FlexCase through the header.
2. You should then follow the specific flashing instructions provided in the development kit documentation for your particular MPU, as the procedure will be identical. This may include rpi boot/RKDevTook/etc.

Note: We do not require that you make other physical changes, such as setting PCB jumpers.