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Hello. I am trying to enable the USB SAM-BA to program my AT91SAM7S Chip. I don't have any Evaluation Kit, I made a custom Header Board and trying to Program the MCU via USB. The Chip is working. I can program the Chip with RS232 SAM-BA. The Problem I am getting in the USB Pull-Up connection: USB D+ ---> 1.5K ----> 3.3V My Windows PC is reporting "Device Not Recognized". Any suggestion .... Thanks in advance. Regards. Sakibnaz.
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Sorry my bad English, I am russian ... To use SAMBA, you must first do 2 steps: 1. Power on your board, connect ERASE pin to +3.3v directly for 1-2 sec. This will erase all CPU's flash memory. 2. Power off board, disconnect ERASE pin from 3.3v, connect TEST pin to +3.3v directly. 3. Power on board, wait 15-sec. In this step CPU rewrites SAMBA from internal ROM to Flash. 4. Power off, disconnect TEST pin from 3.3v. 5. Power on board. SAMBA is works. If you connect board to USB, your computer will detect new hardware and ask driver. Driver is available in SAMBA program installation. Note, you must have external 1.5k pull-up resistor on D+ pin. AT91SAM7S does not have internal resistor. You can see Olmex dev board schematics. There are 2 variants - fixed pull-up and disconnectable by PA16 pin. You always must use only PA16 for this - required by SAM-BA bootloader.
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