Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
|
Forum Index : Microcontroller and PC projects : CMM2: Very important if your PCB uses the MCP2221A
Author | Message | ||||
matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 8516 |
By default the MCP2221A only asks for 100mA from the host. However, it can be configured to request the maximum 500mA using a simple utility. This can be downloaded from the Microchip website but I attach it here for convenience MCP2221Utility.zip Just change the power required to 500mA and then click on the configure button. This is stored in FLASH so it is a one-off requirement. Microbridge equipped CMM2 ask for 500mA by default. Edited 2020-06-20 01:04 by matherp |
||||
JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3641 |
What happens if that's not done? I've not yet found how the utility works or a Linux version... (Or Mac.) John |
||||
matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 8516 |
I think it depends on the host. Most may not limit the output to the requested level but better safe than sorry. |
||||
robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2282 |
here is a good place to start: https://pypi.org/project/PyMCP2221A/ and what needs adjusting is listed in the table on page 6: http://ww1.microchip.com/downloads/en/DeviceDoc/20005565C.pdf REGISTER 1-10: USBREQCRT REGISTER bit 7-0USBREQCRT[7:0]: USB Bus-Powered Required Current Amount bits (in units of 2 mA) Factory default is 50 (decimal); the USB enumeration interprets this value as a current requirement of 100 mA. cheers, rob :-) |
||||
JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3641 |
Cheers, Rob! John |
||||
thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 3807 |
Hey folks, I'm sure the instructions in the first post are sufficient for the electronics savvy who mostly occupy The Back Shed, but I'm just a poor software guy who had only just started to flash LEDs when he was derailed by the arrival of the CMM2. Courtesy of the White Wizzard I have a V3.0 motherboard with a WaveShare and a socketed M2221A. * Is this one of the devices that needs updating? * Why does it need updating? * Do I update the M2221A in situ? * Or is there some sort of "programmer" setup I need to use. Best wishes, Tom Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
||||
matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 8516 |
Yes because, if you are using a computer to supply power it is only requesting 100mA as part of the USB enumeration and the board takes 170-200mA. Most computers probably will supply the power anyway but they are not required to. Of course it is irrelevant if using the CMM2 stand-alone with a USB power supply Yes, just install and run the program I attached in the first post No |
||||
JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3641 |
You do need Windoze, though :( Looks like my board gets enough power anyway. :) John |
||||
thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 3807 |
Thanks Peter, Win10 complained it couldn't install the driver, but then it seemed to work fine anyway <shrugs shoulders> Regards, Tom Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
||||
Womble Senior Member Joined: 09/07/2020 Location: United KingdomPosts: 267 |
I had real difficulty getting this to work. Installed the MCP2221Utility.zip under "Windows 10 Home version 1909 build 18363.900" and it threw an error when installing the driver. As mentioned by "thwill" in a previous post. The error message suggested manually installing the drivers. Even after doing this ... it did not work, the Micromite2/MCP2221A refused to detect. After much head scratching, and resorting to metering the connections from the USB-B socket to the chip, using the excellent schematics as a guide, I discovered that I had a duff connection on the MCP221A socket. No doubt due to my ameteurish soldering. A quick bodge wire later and the device detected instantly. No drivers were required for Windows10, and the MCP2221Utility worked first time. Moral of the story ... check the schematic, and a multimeter is your friend I was convinced it was a Win10 driver issue ... and wasted hours troubleshooting software when in reality it was a bad solder joint / socket pin. Lesson Learnt !!! |
||||
Print this page |