topic Re: imx233 bootlets and no battery board in i.MX Processors

imx233 bootlets and no battery board

mlopez — Wed, 30 Jan 2013 07:20:51 GMT

The default configuration of the bootlet code for the latest i.MX233 support a hardware configuration that has both a LiIon battery configuration. For other configurations though such as a VDD5V connection only or a DCDC_BATT/Battery connection only, some additional changes need to be done.

I'm designing a board with the i.M233 and VDD5V connection with no battery.

What are the additional changes in boot_prep recommended to work this way?

The bootloader also checks the adc to decide which load chain use, based on pressed keys. How could I disable this feature?

Could anyone help me?

Thanks

Re: imx233 bootlets and no battery board

VladanJovanovic — Wed, 30 Jan 2013 17:03:49 GMT

There's some patches for i.MX28 available for this kind of setup. As it's quite similar to i.MX233, it may provide some guidelines on how to do this.

i.MX287 Product Summary Page

Re: imx233 bootlets and no battery board

OtavioSalvador — Wed, 30 Jan 2013 20:12:13 GMT

You may want to look at U-Boot as it has got MX233 support; the code is much easier to follow and hack than bootlets.

The first version with support for MX233 will be 2013.04 but current GIT has it already; other fixes and improvements (as USB support) has been posted today in mailing list.

Re: imx233 bootlets and no battery board

JorgeRama_rezRi — Tue, 05 Feb 2013 22:43:23 GMT

Hi,

I'm not much a SW guy, but I'd like to point there are some details you need to take into account on the HW side. Please take a look to page 4 of the attached for connections for 5V operation.

Best regards.

Jorge.

Re: imx233 bootlets and no battery board

mlopez — Fri, 12 Apr 2013 06:09:29 GMT

Thank you.

I've not seen the revc schematics till now (only revb).

My problem was that in my board, the DC_DC_BAT and BATT pins were not connected.

By placing a 1K pull-up resistor to 4.2V and a 33uF capacitor to ground to both pins connected together, all starts OK without any change in software.