MJ wrote:I've successfully set up Microchip's USB bootloader using an 18F4550, but wondered the reason for using a type B USB connector (square, larger) in all the different sample schematics. Is there any reason you can't use a Type A (flat, familiar interface)?
Type As are typically used for the host, and type Bs (along with the couple mini usb connectors) are typically used for the device. I have yet to see a single type A to type A connector.
They definitely do exist - there is a cable listed on this site (see 'USB Male Type A Connector' under the ordering options) but they are definitely NOT a good idea, unless you are just using them as an extension. They violate the USB spec., and (more importantly) can potentially destroy a device if you plug host->host (a->a) or client->client. Normal USB is NOT a peer-to-peer protocol ordinarily. The devices at the enbds of the cable are not equivalent. I understand that Firewire can do this, and the currently little used USB on-the-go standard allows peer-to-peer. Use miniB connectors for this.
In fact that might be an interesting idea - I believe that Cypress has some USB on-the-go parts. Their documentation does not have a good reputation, butperhaps SparkFun could value-add that.