Hello morse micro team,
pcb3-STM32.pdf (255.9 KB)
pcb3-HALOW.pdf (172.3 KB)
I am using the MM8108-MF15457 halow module in my new board design. The device is interfaced through SPI. I have attached the halow schematic and would appreciate it if you could review the design and let me know if there are any issues or recommended improvements before PCB fabrication.
SPICLK-PB13
SPIMOSI-PC3
SPIMISO-PC2
SPIINT-PB15
SPICS-PE1
BUSY-PE2
WAKE-PD0
Thank you for your support.
Hey @akhil
I notice you are using an STM32F407? Have you assessed the RAM and flash usage of your application? 1MB of flash and 192KB of RAM will probably work for very light applications, but as you start to do more complex activities (eg firmware upgrades, managing multiple connections, certificate chains for SSL backed connections, specific throughput requirements) you might find you will consume these RAM and flash offered by this target relatively quickly. I’d recommend prototyping the design on a nucleo first if you haven’t already 
If your debugger has a spare pin. I’d recommend breaking out MM_BUSY onto it so you can attach a logic analyser if needed.
Otherwise the schematics look okay to me. Please make sure you check them against the MM8108-MF15457 Hardware Design Guide as well as I may have missed something.
Hi @ajudge
Thank you for your review and feedback
Sir,
I have a few doubts regarding the MM8108 HaLow module:
Why does the MM8108 HaLow firmware need to be sent from the STM32 to the MM8108 over SPI after every MM8108 reset or power cycle?
For the development board I am currently using, where can I find the BUSY pin ? Is there any option to purchase a development board with only the HaLow IC/module? Also, when is the MM8108-EKH08-01-01 expected to be released?
Thank you.
The firmware is loaded into RAM as the chip does not have internal flash. This means it needs to be loaded on boot.
Which development board are you using? The EKH05? You can refer to the user guide schematic for this (the resolution isn’t great sorry) https://morsemicro.com/resources/user_guides/MM8108-EKH05-User-Guide.pdf
I believe we don’t currently have a timeline for this, but will let you know if we do release it.
Sir,
We are currently using the STM32F407G-DISC1 development board with the MM8108-EKH05. I have already ported the required code and am currently testing it. However, I am facing an issue during the firmware transfer, where the firmware transmission fails.
Could this issue be related to the BUSY pin? The MM8108-EKH05 board does not have an accessible BUSY pin test point. If the BUSY pin is required, is there any alternative method to access the BUSY pin from the board?
For testing purposes, if I use the available MM6108-EKH08-05US-01 module and first verify that the firmware and communication are working correctly, can I later switch to the MM8108-EKH05 HaLow IC?
Specifically, are the MM6108 and MM8108 compatible with the same firmware, drivers, and SPI communication implementation, or would separate firmware/configuration changes be required?
Thank you.
The chip firmware and driver are different, but we deliver both of those, and swapping between should be as simple as changing the MMHAL_CHIP_TYPE and FW_MBIN.
The mmhal_wlan abstraction layer for interfacing with the chip over SPI is agnostic to the chip and shouldn’t need to change.
For accessing the busy (and wake!) pin, I think your best bet is to use the test points around the chip - see here where I discussed this with another user: "mm8108-ekh05 v2" + esp32-p4 - #2 by ldennis
Could you please mention which pin is used for the BUSY signal? I’m unable to identify the BUSY pin from the schematic.
Accessing the busy pin on this board will be challenging, as it has no test point available. The most accessible point will be pin 91 on the STM32U585.
Sir,
Just to confirm, does this mean that the same host-side firmware/software can support both the MM6108 and MM8108, with only MMHAL_CHIP_TYPE and FW_MBIN needing to be changed, while the mmhal_wlan SPI abstraction layer remains unchanged?
Can you please confirm whether this is fully supported for both chips, including firmware download, initialization, and normal Wi-Fi HaLow operation?
Yes, that is correct
Sir,
I would like to clarify all the available SPI test points/pins on this board MM6108-EKH08-05US-02.
Please confirm, especially the BUSY pin is available on this board MM6108-EKH08-05US-02?
All the needed pins are available, see here: Morse Micro IoT SDK: mm-ekh08-u575 SPI Readme
yes, that’s the one I linked - the pinout of the SPI EKH08 boards are all the same, and only differ by what module is loaded.
